Extrapolating the INE

PNRJ critique of neoclassical economics, current events, inequality, public policy , , , , , , , , , , ,

Apr 6 JDN 2460772

I was only able to find sufficient data to calculate the Index of Necessary Expenditure back to 1990. But I found a fairly consistent pattern that the INE grew at a rate about 20% faster than the CPI over that period, so I decided to take a look at what longer-term income growth looks like if we extrapolate that pattern back further in time.

The result is this graph:

Using the CPI, real per-capita GDP in the US (in 2024 dollars) has grown from $25,760 in 1950 to $85,779 today—increasing by a factor of 3.33. Even accounting for increased inequality and the fact that more families have two income earners, that’s still a substantial increase.

But using the extrapolated INE, real per-capita GDP has only grown from $43,622 in 1950 to $85,779 today—increasing by only a factor of 1.97. This is a much smaller increase, especially when we adjusted for increased inequality and increased employment for women.

Even without the extrapolation, it’s still clear that real INE-adjusted incomes have were basically stagnant in the 2000s, increased rather slowly in the 2020s, and then actually dropped in 2022 after a bunch of government assistance ended. What looked, under the CPI, like steadily increasing real income was actually more like treading water.

Should we trust this extrapolation? It’s a pretty simplistic approach, I admit. But I think it is plausible when we consider this graph of the ratio between median income and median housing price:

This ratio was around 6 in the 1950s, then began to fall until in the 1970s it stabilized around 4. It began to slowly creep back up, but then absolutely skyrocketed in the 2000s before the 2008 crash. Now it has been rising again, and is now above 7, the highest it has been since the Second World War. (Does this mean we’re due for another crash? I’d bet as much.)

What does this mean? It means that a typical family used to be able to afford a typical house with only four years of their total income—and now would require seven. In that sense, homes are now 75% more expensive today than they were in the 1970s.

Similar arguments can be made for the rising costs of education and healthcare; while many prices have not grown much (gasoline) or even fallen (jewelry and technology), these necessities have continued to grow more and more expensive, not simply in nominal terms, but even compared to the median income.

This is further evidence that our standard measures of “inflation” and “real income” are fundamentally inadequate. They simply aren’t accurately reflecting the real cost of living for most American families. Even in many times when it seemed “inflation” was low and “real income” was growing, in fact it was growing harder and harder to afford vital necessities such as housing, education, and healthcare.

This economic malaise may have been what contributed to the widespread low opinion of Biden’s economy. While the official figures looked good, people’s lives weren’t actually getting better.

Yet this is still no excuse for those who voted for Trump; even the policies he proudly announced he would do—like tariffs and deportations—have clearly made these problems worse, and this was not only foreseeable but actually foreseen by the vast majority of the world’s economists. Then there are all the things he didn’t even say he would do but is now doing, like cozying up to Putin, alienating our closest allies, and discussing “methods” for achieving an unconstitutional third term.

Indeed, it honestly feels quite futile to even reflect upon what was wrong with our economy even when things seemed to be running smoothly, because now things are rapidly getting worse, and showing no sign of getting better in any way any time soon.

A new theoretical model of co-ops

PNRJ critique of neoclassical economics, inequality, market failure, mathematical models, public policy , , , , , , , , ,

Mar 30 JDN 2460765

A lot of economists seem puzzled by the fact that co-ops are just as efficient as corporate firms, since they have this idea that profit-sharing inevitably results in lower efficiency due to perverse incentives.

I think they’ve been modeling co-ops wrong. Here I present a new model, a very simple one, with linear supply and demand curves. Of course one could make a more sophisticated model, but this should be enough to make the point (and this is just a blog post, not a research paper, after all).

Demand curve is p = a – b q

Marginal cost is f q

There are n workers, who would hold equal shares of the co-op.

Competitive market

First, let’s start with the traditional corporate firm in a competitive market.

Since the market is competitive, price would equal marginal cost would equal wage:

a – b q = d q

q = a/(b+f)

w = d (a/(b+f)) = (a d)/(b+f)

Total profit will be

(p – w)q = 0.

Monopoly firm

In a monopoly, marginal revenue would equal marginal cost:
d[pq]/dq = a – 2 b q

If they are also a monopsonist in the labor market, this marginal cost would be marginal cost of labor, not wage:

d[d q2]/dq = 2 f q

a – 2 b q = 2 f q

q = a/(2b + 2f)

p = a – b q = a (1 – b/(2b + 2f)) = (a (b + 2f))/(2b + 2f)

w = d q = (a f)/(2b + 2f)

Total profit will be

(p – w) q = ((a (b + 2f))/(2b + 2f) – (a f)/(2b + 2f))a/(2b + 2f) = a2/(4b + 2f)

Now consider the co-op.

First, suppose that instead of working for a wage, I work for profit sharing.

If our product market is competitive, we’ll be price-takers, and we will produce until price equals marginal cost:

p = f q

a – b q = f q

q = a/(a+b)

But will we, really? I only get 1/n share of the profits. So let’s see here. My marginal cost of production is still f q, but the marginal benefit I get from more sales may only be p/n.

In that case I would work until:

p/n = f q

(a – b q)/n = fq

a – b q = n f q

q = (a/(b+nf))

Thus I would under-produce. This is the usual argument against co-ops and similar shared ownership.

Co-ops with wages

But that’s not actually how co-ops work. They pay wages. Why do they do that? Well, consider what happens if I am offered a wage as a worker-owner of the co-op.

Is there any reason for the co-op to vote on a wage that is less than the competitive market? No, because owners are workers, so any additional profit from a lower wage would simply be taken from their own wages.

If there any reason for the co-op to vote on a wage that is more than the competitive market? No, because workers are owners, and any surplus lost by paying higher wages would simply be taken from their own profits.

So if the product market is competitive, the co-op will produce the same amount and charge the same price as a firm in perfect competition, even if they have market power over their own wages.

Monopoly co-ops

The argument above doesn’t assume that the co-op has no market power in the labor market. Thus if they are a monopoly in the product market and a monopsony in the labor market, they still pay a competitive wage.

Thus they would set marginal revenue equal to marginal cost:

a – 2 b q = f q

q = a/(2b + f)

The co-op will produce more than the monopoly firm..

This is the new price:

p = a – b q = a(1 – b/(2b+f)) = a(b+f)/(2b + f)

It’s not obvious that this is lower than the price charged by the monopoly firm, but it is.

(a (b + 2f))/(2b + 2f) – a(b+f)/(2b + f) = (a (2b + f)(b + 2f) – 2 a(b+f)2)/(2(b+f)(2b+f))

This is proportional to:

(2b + f)(b + 2f) – 2(b+f)2

2b2 + 5bf + 2f2 – (2b2 + 4bf + 2f2) = bf

So it’s not a large difference, but it’s there. In the presence of market power in the labor market, the co-op is better for consumers, because they get more goods and pay a lower price.

Thus, there is actually no lost efficiency from being a co-op. There is simply much lower inequality, and potentially higher efficiency.

But that’s just in theory.

What do we see in practice?

Exactly that.

Co-ops have the same productivity and efficiency as corporate firms, but they pay higher wages, provide better benefits, and offer collateral benefits to their communities. In fact, they are sometimes more efficient than corporate firms.

Since they’re just as efficient—if not more so—and produce much lower inequality, switching more firms over to co-ops would clearly be a good thing.

Why, then, aren’t co-ops more common?

Because the people who have the money don’t like them.

The biggest barrier facing co-ops is their inability to get financing, because they don’t pay shareholders (so no IPOs) and banks don’t like to lend to them. They tend to make less profit than corporate firms, which offers investors a lower return—instead that money goes to the worker-owners. This lower return isn’t due to inefficiency; it’s just a different distribution of income, more to labor and less to capital.

We will need new financial institutions to support co-ops, such as the Cooperative Fund of New England. And general redistribution of wealth would also help, because if middle class people had more wealth they could afford to finance co-ops. (It would also be good for many other reasons, of course.)

Reflections on the Index of Necessary Expenditure

PNRJ inequality, macroeconomics, public policy, statistics , , , , , , , , , , , ,

Mar 16 JDN 2460751

In last week’s post I constructed an Index of National Expenditure (INE), attempting to estimate the total cost of all of the things a family needs and can’t do without, like housing, food, clothing, cars, healthcare, and education. What I found shocked me: The median family cannot afford all necessary expenditures.

I have a couple more thoughts about that.

I still don’t understand why people care so much about gas prices.

Gasoline was a relatively small contribution to INE. It was more than clothing but less than utilities, and absolutely dwarfed by housing, food, or college. I thought maybe since I only counted a 15-mile commute, maybe I didn’t actually include enoughgasoline usage, but based on this estimate of about $2000 per driver, I was in about the right range; my estimate for the same year was $3350 for a 2-car family.

I think I still have to go with my salience hypothesis: Gasoline is the only price that we plaster in real-time on signs on the side of the road. So people are constantly aware of it, even though it isn’t actually that important.

The price surge that should be upsetting people is housing.

If the price of homes had only risen with the rate of CPI inflation instead of what it actually did, the median home price in 2024 would be only $234,000 instead of the $396,000 it actually is; and by my estimation that would save a typical family $11,000 per year—a whopping 15% of their income, and nearly enough to make the INE affordable by itself.

Now, I’ll consider some possible objections to my findings.

Objection 1: A typical family doesn’t actually spend this much on these things.

You’re right, they don’t! Because they couldn’t possibly. Even with substantial debt, you just can’t sustainably spend 125% of your after-tax household income.

My goal here was not to estimate how much families actually spend; it was to estimate how much they need to spend in order to live a good life and not feel deprived.


What I have found is that most American families feel deprived. They are forced to sacrifice something really important—like healthcare, or education, or owning a home—because they simply can’t afford it.

What I’m trying to do here is find the price of the American Dream; and what I’ve found is that the American Dream has a price that most Americans cannot afford.

Objection 2: You should use median healthcare spending, not mean.

I did in fact use mean figures instead of median for healthcare expenditures, mainly because only the mean was readily available. Mean income is higher than median income, so you might say that I’ve overestimated healthcare expenditure—and in a sense that’s definitely true. The median family spends less than this on healthcare.

But the reason that the median family spends less than this on healthcare is not that they want to, but that they have to. Healthcare isn’t a luxury that people buy more of because they are richer. People buy either as much as they need or as much as they can afford—whichever is lower, which is typically the latter. Using the mean instead of the median is a crude way to account for that, but I think it’s a defensible one.

But okay, let’s go ahead and cut the estimate of healthcare spending in half; even if you do that, the INE is still larger than after-tax median household income in most years.

Objection 3: A typical family isn’t a family of four, it’s a family of three.

Yes, the mean number of people in a family household in the US is 3.22 (the median is 3).

This is a very bad thing.

Part of what I seem to be finding here is that a family of four is unaffordable—literally impossible to afford—on a typical family income.

But a healthy society is one in which typical families have two or three children. That is what we need in order to achieve population replacement. When families get smaller than that, we aren’t having enough children, and our population will decline—which means that we’ll have too many old people relative to young people. This puts enormous pressure on healthcare and pension systems, which rely upon the fact that young people produce more, in order to pay for the fact that old people cost more.

The ideal average number of births per woman is about 2.1; this is what would give us a steady population. No US state has fertility above this level. The only reason the US population is growing rather than shrinking is that we are taking in immigrants.

This is bad. This is not sustainable. If the reason families aren’t having enough kids is that they can’t afford them—and this fits with other research on the subject—then this economic failure damages our entire society, and it needs to be fixed.

Objection 4: Many families buy their cars used.

Perhaps 1/10 of a new car every year isn’t an ideal estimate of how much people spend on their cars, but if anything I think it’s conservative, because if you only buy a car every 10 years, and it was already used when you bought it, you’re going to need to spend a lot on maintaining it—quite possibly more than it would cost to get a new one. Motley Fool actually estimates the ownership cost of just one car at substantially more than I estimated for two cars. So if anything your complaint should be that I’ve underestimated the cost by not adequately including maintenance and insurance.

Objection 5: Not everyone gets a four-year college degree.

Fair enough; a substantial proportion get associate’s degrees, and most people get no college degree at all. But some also get graduate degrees, which is even more expensive (ask me how I know).

Moreover, in today’s labor market, having a college degree makes a huge difference in your future earnings; a bachelor’s degree increases your lifetime earnings by a whopping 84%. In theory it’s okay to have a society where most people don’t go to college; in practice, in our society, not going to college puts you at a tremendous disadvantage for the rest of your life. So we either need to find a way to bring wages up for those who don’t go to college, or find a way to bring the cost of college down.

This is probably one of the things that families actually choose to scrimp on, only sending one kid to college or none at all. But because college is such a huge determinant of earnings, this perpetuates intergenerational inequality: Only rich families can afford to send their kids to college, and only kids who went to college grow up to have rich families.

Objection 6: You don’t actually need to save for college; you can use student loans.

Yes, you can, and in practice, most people who to college do. But while this solves the liquidity problem (having enough money right now), it does not solve the solvency problem (having enough money in the long run). Failing to save for college and relying on student loans just means pushing the cost of college onto your children—and since we’ve been doing that for over a generation, feel free to replace the category “college savings” with “repaying student loans”; it won’t meaningfully change the results.

The Index of Necessary Expenditure

PNRJ core principles, critique of neoclassical economics, current events, inequality, politics, public policy, statistics , , , , , , , , , ,

Mar 16 JDN 2460751

I’m still reeling from the fact that Donald Trump was re-elected President. He seemed obviously horrible at the time, and he still seems horrible now, for many of the same reasons as before (we all knew the tariffs were coming, and I think deep down we knew he would sell out Ukraine because he loves Putin), as well as some brand new ones (I did not predict DOGE would gain access to all the government payment systems, nor that Trump would want to start a “crypto fund”). Kamala Harris was not an ideal candidate, but she was a good candidate, and the comparison between the two could not have been starker.

Now that the dust has cleared and we have good data on voting patterns, I am now less convinced than I was that racism and sexism were decisive against Harris. I think they probably hurt her some, but given that she actually lost the most ground among men of color, racism seems like it really couldn’t have been a big factor. Sexism seems more likely to be a significant factor, but the fact that Harris greatly underperformed Hillary Clinton among Latina women at least complicates that view.

A lot of voters insisted that they voted on “inflation” or “the economy”. Setting aside for a moment how absurd it was—even at the time—to think that Trump (he of the tariffs and mass deportations!) was going to do anything beneficial for the economy, I would like to better understand how people could be so insistent that the economy was bad even though standard statistical measures said it was doing fine.

Krugman believes it was a “vibecession”, where people thought the economy was bad even though it wasn’t. I think there may be some truth to this.


But today I’d like to evaluate another possibility, that what people were really reacting against was not inflation per se but necessitization.

I first wrote about necessitization in 2020; as far as I know, the term is my own coinage. The basic notion is that while prices overall may not have risen all that much, prices of necessities have risen much faster, and the result is that people feel squeezed by the economy even as CPI growth remains low.

In this post I’d like to more directly evaluate that notion, by constructing an index of necessary expenditure (INE).

The core idea here is this:

What would you continue to buy, in roughly the same amounts, even if it doubled in price, because you simply can’t do without it?

For example, this is clearly true of housing: You can rent or you can own, but can’t not have a house. And nor are most families going to buy multiple houses—and they can’t buy partial houses.

It’s also true of healthcare: You need whatever healthcare you need. Yes, depending on your conditions, you maybe could go without, but not without suffering, potentially greatly. Nor are you going to go out and buy a bunch of extra healthcare just because it’s cheap. You need what you need.

I think it’s largely true of education as well: You want your kids to go to college. If college gets more expensive, you might—of necessity—send them to a worse school or not allow them to complete their degree, but this would feel like a great hardship for your family. And in today’s economy you can’t not send your kids to college.

But this is not true of technology: While there is a case to be made that in today’s society you need a laptop in the house, the fact is that people didn’t used to have those not that long ago, and if they suddenly got a lot cheaper you very well might buy another one.

Well, it just so happens that housing, healthcare, and education have all gotten radically more expensive over time, while technology has gotten radically cheaper. So prima facie, this is looking pretty plausible.

But I wanted to get more precise about it. So here is the index I have constructed. I consider a family of four, two adults, two kids, making the median household income.

To get the median income, I’ll use this FRED series for median household income, then use this table of median federal tax burden to get an after-tax wage. (State taxes vary too much for me to usefully include them.) Since the tax table ends in 2020 which was anomalous, I’m going to extrapolate that 2021-2024 should be about the same as 2019.

I assume the kids go to public school, but the parents are saving up for college; to make the math simple, I’ll assume the family is saving enough for each kid to graduate from with a four-year degree from a public university, and that saving is spread over 16 years of the child’s life. 2*4/16 = 0.5; this means that each year the family needs to come up with 0.5 years of cost of attendance. (I had to get the last few years from here, but the numbers are comparable.)

I assume the family owns two cars—both working full time, they kinda have to—which I amortize over 10 year lifetimes; 2*1/10 = 0.2, so each year the family pays 0.2 times the value of an average midsize car. (The current average new car price is $33226; I then use the CPI for cars to figure out what it was in previous years.)

I assume they pay a 30-year mortgage on the median home; they would pay interest on this mortgage, so I need to factor that in. I’ll assume they pay the average mortgage rate in that year, but I don’t want to have to do a full mortgage calculation (including PMI, points, down payment etc.) for each year, so I’ll say that they amount they pay is (1/30 + 0.5 (interest rate))*(home value) per year, which seems to be a reasonable approximation over the relevant range.

I assume that both adults have a 15-mile commute (this seems roughly commensurate with the current mean commute time of 26 minutes), both adults work 5 days per week, 50 weeks per year, and their cars get the median level of gas mileage. This means that they consume 2*15*2*5*50/(median MPG) = 15000/(median MPG) gallons of gasoline per year. I’ll use this BTS data for gas mileage. I’m intentionally not using median gasoline consumption, because when gas is cheap, people might take more road trips, which is consumption that could be avoided without great hardship when gas gets expensive. I will also assume that the kids take the bus to school, so that doesn’t contribute to the gasoline cost.

That I will multiply by the average price of gasoline in June of that year, which I have from the EIA since 1993. (I’ll extrapolate 1990-1992 as the same as 1993, which is conservative.)

I will assume that the family owns 2 cell phones, 1 computer, and 1 television. This is tricky, because the quality of these tech items has dramatically increased over time.

If you try to measure with equivalent buying power (e.g. a 1 MHz computer, a 20-inch CRT TV), then you’ll find that these items have gotten radically cheaper; $1000 in 1950 would only buy as much TV as $7 today, and a $50 Raspberry Pi‘s 2.4 GHz processor is 150 times faster than the 16 MHz offered by an Apple Powerbook in 1991—despite the latter selling for $2500 nominally. So in dollars per gigahertz, the price of computers has fallen by an astonishing 7,500 times just since 1990.

But I think that’s an unrealistic comparison. The standards for what was considered necessary have also increased over time. I actually think it’s quite fair to assume that people have spent a roughly constant nominal amount on these items: about $500 for a TV, $1000 for a computer, and $500 for a cell phone. I’ll also assume that the TV and phones are good for 5 years while the computer is good for 2 years, which makes the total annual expenditure for 2 phones, a TV, and a computer equal to 2/5*500 + 1/5*500 + 1/2*1000 = 800. This is about what a family must spend every year to feel like they have an adequate amount of digital technology.

I will also assume that the family buys clothes with this equivalent purchasing power, with an index that goes from 166 in 1990 to 177 in 2024—also nearly constant in nominal terms. I’ll multiply that index by $10 because the average annual household spending on clothes is about $1700 today.

I will assume that the family buys the equivalent of five months of infant care per year; they surely spend more than this (in either time or money) when they have actual infants, but less as the kids grow. This amounts to about $5000 today, but was only $1600 in 1990—a 214% increase, or 3.42% per year.

For food expenditure, I’m going to use the USDA’s thrifty plan for June of that year. I’ll use the figures assuming that one child is 6 and the other is 9. I don’t have data before 1994, so I’ll extrapolate that with the average growth rate of 3.2%.

Food expenditures have been at a fairly consistent 11% of disposable income since 1990; so I’m going to include them as 2*11%*40*50*(after-tax median wage) = 440*(after-tax median wage).

The figures I had the hardest time getting were for utilities. It’s also difficult to know what to include: Is Internet access a necessity? Probably, nowadays—but not in 1990. Should I separate electric and natural gas, even though they are partial substitutes? But using these figures I estimate that utility costs rise at about 0.8% per year in CPI-adjusted terms, so what I’ll do is benchmark to $3800 in 2016 and assume that utility costs have risen by (0.8% + inflation rate) per year each year.

Healthcare is also a tough one; pardon the heteronormativity, but for simplicity I’m going to use the mean personal healthcare expenditures for one man and woman (aged 19-44) and one boy and one girl (aged 0-18). Unfortunately I was only able to find that for two-year intervals in the range from 2002 to 2020, so I interpolated and extrapolated both directions assuming the same average growth rate of 3.5%.

So let’s summarize what all is included here:

  • Estimated payment on a mortgage
  • 0.5 years of college tuition
  • amortized cost of 2 cars
  • 7500/(median MPG) gallons of gasoline
  • amortized cost of 2 phones, 1 computer, and 1 television
  • average spending on clothes
  • 11% of income on food
  • Estimated utilities spending
  • Estimated childcare equivalent to five months of infant care
  • Healthcare for one man, one woman, one boy, one girl

There are obviously many criticisms you could make of these choices. If I were writing a proper paper, I would search harder for better data and run robustness checks over the various estimation and extrapolation assumptions. But for these purposes I really just want a ballpark figure, something that will give me a sense of what rising cost of living feels like to most people.

What I found absolutely floored me. Over the range from 1990 to 2024:

  1. The Index of Necessary Expenditure rose by an average of 3.45% per year, almost a full percentage point higher than the average CPI inflation of 2.62% per year.
  2. Over the same period, after-tax income rose at a rate of 3.31%, faster than CPI inflation, but slightly slower than the growth rate of INE.
  3. The Index of Necessary Expenditure was over 100% of median after-tax household income every year except 2020.
  4. Since 2021, the Index of Necessary Expenditure has risen at an average rate of 5.74%, compared to CPI inflation of only 2.66%. In that same time, after-tax income has only grown at a rate of 4.94%.

Point 3 is the one that really stunned me. The only time in the last 34 years that a family of four has been able to actually pay for all necessities—just necessities—on a typical household income was during the COVID pandemic, and that in turn was only because the federal tax burden had been radically reduced in response to the crisis. This means that every single year, a typical American family has been either going further and further into debt, or scrimping on something really important—like healthcare or education.

No wonder people feel like the economy is failing them! It is!

In fact, I can even make sense now of how Trump could convince people with “Are you better off than you were four years ago?” in 2024 looking back at 2020—while the pandemic was horrific and the disruption to the economy was massive, thanks to the US government finally actually being generous to its citizens for once, people could just about actually make ends meet. That one year. In my entire life.

This is why people felt betrayed by Biden’s economy. For the first time most of us could remember, we actually had this brief moment when we could pay for everything we needed and still have money left over. And then, when things went back to “normal”, it was taken away from us. We were back to no longer making ends meet.

When I went into this, I expected to see that the INE had risen faster than both inflation and income, which was indeed the case. But I expected to find that INE was a large but manageable proportion of household income—maybe 70% or 80%—and slowly growing. Instead, I found that INE was greater than 100% of income in every year but one.

And the truth is, I’m not sure I’ve adequately covered all necessary spending! My figures for childcare and utilities are the most uncertain; those could easily go up or down by quite a bit. But even if I exclude them completely, the reduced INE is still greater than income in most years.

Suddenly the way people feel about the economy makes a lot more sense to me.

Evolutionary skepticism

PNRJ ethics, Logic of Kindness, tribal paradigm , , , , , , ,

Post 572 Mar 9 JDN 2460744

In the last two posts I talked about ways that evolutionary theory could influence our understanding of morality, including the dangerous views of naive moral Darwinism as well as some more reasonable approaches; yet there are other senses of the phrase “morality evolves” that we haven’t considered. One of these is actually quite troubling; were it true, the entire project of morality would be in jeopardy. I’ll call it “evolutionary skepticism”; it says that yes, morality has evolved—and this is reason to doubt that morality is true. Richard Joyce, author of The Evolution of Morality, is of such a persuasion, and he makes a quite compelling case. Joyce’s central point is that evolution selects for fitness, not accuracy; we had reason to evolve in ways that would maximize the survival of our genes, not reasons to evolve in ways that would maximize the accuracy of our moral claims.

This is of course absolutely correct, and it is troubling precisely because we can all see that the two are not necessarily the same thing. It’s easy to imagine many ways that beliefs could evolve that had nothing to do with the accuracy of those beliefs.

But note that word: necessarily. Accuracy and fitness aren’t necessarily aligned—but it could still be that they are, in fact, aligned rather well. Yes, we can imagine ways a brain could evolve that would benefit its fitness without improving its accuracy; but is that actually what happened to our ancestors? Do we live on instinct, merely playing out by rote the lifestyles of our forebears, thinking and living the same way we have for hundreds of millennia?

Clearly not! Behold, you are reading a blog post! It was written on a laptop computer! While these facts may seem perfectly banal to you, they represent an unprecedented level of behavioral novelty, one achieved only by one animal species among millions, and even then only very recently. Human beings are incredibly flexible, incredibly creative, and incredibly intelligent. Yes, we evolved to be this way, of course we did; but so what? We are this way. We are capable of learning new things about the world, gaining in a few short centuries knowledge our forebears could never have imagined. Evolution does not always make animals into powerful epistemic engines—indeed, 99.99999\% of the time it does not—but once in awhile it does, and we are the result.

Natural selection is quite frugal; it tends to evolve things the easiest way. The way the world is laid out, it seems to be that the easiest way to evolve a brain that survives really well in a wide variety of ecological and social environments is to evolve a brain that is capable of learning to expand its own knowledge and understanding. After all, no other organism has ever been or is ever likely to be as evolutionarily fit as we are; we span the globe, cover a wide variety of ecological niches, and number in the billions and counting. We’ve even expanded beyond the planet Earth, something no other organism could even contemplate. We are successful because we are smart; is it really so hard to believe that we are smart because it made our ancestors successful?

Indeed, it must be this way, or we wouldn’t be able to make sense of the fact that our human brains, evolved for the African savannah a million years ago with minor tweaks since then, are capable of figuring out chess, calculus, writing, quantum mechanics, special relativity, television broadcasting, space travel, and for that matter Darwinian evolution and meta-ethics. None of these things could possibly have been adaptive in our ancestral ecology. They must be spandrels, fitness-neutral side-effects of evolved traits. And just like the original pendentives of San Marco that motivated Gould’s metaphor, what glorious spandrels they are!

Our genes made us better at gathering information and processing that information into correct beliefs, and calculus and quantum mechanics came along for the ride. Our greatest adaptation is to be adaptable; our niche is to need no niche, for we can carve our own.

This is not to abandon evolutionary psychology, for evolution does have a great deal to tell us about psychology. We do have instincts; preprocessing systems built into our sensory organs, innate emotions that motivate us to action, evolved heuristics that we use to respond quickly under pressure. Steven Pinker argues convincingly that language is an evolved instinct—and where would we be without language? Our instincts are essential for not only our survival, but indeed for our rationality.

Staring at a blinking cursor on the blank white page of a word processor, imagining the infinity of texts that could be written upon that page, you could be forgiven for thinking that you were looking at a blank slate. Yet in fact you are staring at the pinnacle of high technology, an extremely complex interlocking system of hardware and software with dozens of components and billions of subcomponents, all precision-engineered for maximum efficiency. The possibilities are endless not because the system is simple and impinged upon by its environment, but because it is complex, and capable of engaging with that environment in order to convert subtle differences in input into vast differences in output. If this is true of a word processor, how much more true it must be of an organism capable of designing and using word processors! It is the very instincts that seem to limit our rationality which have made that rationality possible in the first place. Witness the eternal wisdom of Immanuel Kant:

Misled by such a proof of the power of reason, the demand for the extension of knowledge recognises no limits. The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would be still easier in empty space.

The analogy is even stronger than he knew—for brains, like wings, are an evolutionary adaptation! (What would Kant have made of Darwin?) But because our instincts are so powerful, they are self-correcting; they allow us to do science.

Richard Joyce agrees that we are right to think our evolved brains are reasonably reliable when it comes to scientific facts. He has to, otherwise his whole argument would be incoherent. Joyce agrees that we evolved to think 2+2=4 precisely because 2+2=4, and we evolved to think space is 3-dimensional precisely because space is 3-dimensional. Indeed, he must agree that we evolved to think that we evolved because we evolved! Yet, for some reason Joyce thinks that this same line of reasoning doesn’t apply to ethics.

But why wouldn’t it? In fact, I think we have more reason to trust our evolved capacities in ethics than we do in other domains of science, because the subject matter of morality—human behavior and social dynamics—is something that we have been familiar with even all the way back to the savannah. If we evolved to think that theft and murder are bad, why would that happen? I submit it would happen precisely because theft and murder are Pareto-suboptimal unsustainable strategies—that is, precisely because theft and murder are bad. (Don’t worry if you don’t know what I mean by “Pareto-suboptimal” and “unsustainable strategy”; I’ll get to those in later posts.) Once you realize that “bad” is a concept that can ultimately be unpacked to naturalistic facts, all reason to think it is inaccessible to natural selection drops away; natural selection could well have chosen brains that didn’t like murder precisely because murder is bad. Indeed, because morality is ultimately scientific, part of how natural selection could evolve us to be more moral is by evolving us to be more scientific. We are more scientific than apes, and vastly more scientific than cockroaches; we are, indeed, the most scientific animal that has ever lived on Earth.

I do think that our evolved moral instincts are to some degree mistaken or incomplete; but I can make sense of this, in the same way I make sense of the fact that other evolved instincts don’t quite fit what we have discovered in other sciences. For instance, humans have an innate concept of linear momentum that doesn’t quite fit with what we’ve discovered in physics. We tend to presume that objects have an inherent tendency toward rest, though in fact they do not—this is because in our natural environment, friction makes most objects act as if they had such a tendency. Roll a rock along the ground, and it will eventually stop. Run a few miles, and eventually you’ll have to stop too. Most things in our everyday life really do behave as if they had an inherent tendency toward rest. It’s only once we realized that friction is itself a force, not present everywhere, that we came to see that linear momentum is conserved in the absence of external forces. (Throw a rock in space, and it will not ever stop. Nor will you, by Newton’s Third Law.) This casts no doubt upon our intuitions about rocks rolled along the ground, which do indeed behave exactly as our intuition predicts.

Similarly, our intuition that animals don’t deserve rights could well be an evolutionary consequence of the fact that we sometimes had to eat animals in order to survive, and so would do better not thinking about it too much; but now that we don’t need to do this anymore, we can reflect upon the deeper issues involved in eating meat. This is no reason to doubt our intuitions that parents should care for their children and murder is bad.

Other approaches to evolutionary ethics

PNRJ ethics, tribal paradigm , , , , , , , , , , ,

Mar 2 JDN 2460737

In my previous post, I talked about some ways that evolutionary theory can be abused in ethics, leading to abhorrent conclusions. This is all too common; but it doesn’t mean that evolutionary theory has nothing useful to say about ethics.

There are other approaches to evolutionary ethics that do not lead to such horrific conclusions; one such approach is evolutionary anthropocentrism; it is a position held by respected thinkers such as Frans de Waal, but it is still flawed. The claim is that certain behaviors are moral because we have evolved to do them—that behaviors like friendship, marriage, and nationalism are good precisely because they are part of human nature. On this theory, we can discern what is right and wrong for human beings simply by empirically studying what behaviors are universal or adaptive among human beings.

While I applaud the attempt to understand morality scientifically, I must ultimately conclude that the peculiar history of human evolution is far too parochial a basis for any deep moral truths. Another species—from the millions of other life forms with which we share the Earth to the millions of extraterrestrial civilizations that must in all probability exist somewhere in the vastness of the universe—could have a completely different set of adaptations, and hence a completely incompatible moral system.

Is a trait good because it evolved, or did it evolve because it is good? If the former then “good” just means “fit” and human beings are no more moral than rats or cockroaches. Indeed, the most fit human being of all time was the Moroccan tyrant Mulai Ismail, who reputedly fathered 800 children; the least fit include Isaac Newton and Alan Turing, who had no children at all. To say that evolution gets it right—as, with qualifications, I will—is to say that there is a right, independent of what did or did not evolve; if evolution can get it right, then it could also, under other circumstances, get it wrong.

For illustration, imagine a truly alien form of life, one with which we share no common ancestor and only the most basic similarities. Such creatures likely exist in the vastness of the universe, though of course we’ve never encountered any. Perhaps somewhere in one of the nearby arms of our galaxy there is an unassuming planet inhabited by a race of ammonia-based organisms, let’s call them the Extrans, whose “eyes” see in the radio spectrum, whose “ears” are attuned to frequencies lower than we can hear, whose “nerves” transmit signals by fiber optics instead of electricity, whose “legs” are twenty frond-structured fins that propel them through the ammonia sea, whose “hands” are three long prehensile tentacles extending from their heads, whose “language” is a pattern of radio transmissions produced by their four dorsal antennae. Now, imagine that this alien species has managed to develop sufficient technology so that over millions of years they have colonized all the nearby planets with sufficient ammonia to support them. Yet, their population continues to grow—now in the hundreds of trillions—and they cannot find enough living space to support it. One of their scientists has discovered a way to “ammoniform” certain planets—planets with a great deal of water and nitrogen can be converted into ammonia-supporting planets. There’s only one problem: The nearest water-nitrogen planet is called Earth, and there are already seven billion humans (not to mention billions of other lifeforms) living on it who would surely die if the ammoniforming were performed. The ammoniformer ship has just entered our solar system; we have managed to establish radio contact and achieve some rudimentary level of translation between our radically different languages. What do we say to the Extrans?

If morality is to have a truly objective meaning, we ought to be able to explain in terms the Extrans could accept and understand why it would be wrong for them to ammoniform our planet while we are still living on it. We ought to be able to justify to these other intelligent beings, however different they are from us chemically, biologically, psychologically, and technologically, why we are creatures of dignity who deserve not to be killed. Otherwise, the species with superior weapons will win; and if they can get here, that will probably be them, not us.

Sam Harris has said several times, “morality could be like food”; by this he seems to mean that there is objective evaluation that can be made about the nutrition versus toxicity of a given food, even if there is no one best food, and similarly that objective evaluation can be made about the goodness or badness of a moral system even if there is no one best moral system. This makes a great deal of sense to me, but the analogy can also be turned against him, for if morality is just as contingent upon our biology as diet, then who are we to question these Extrans in their quest for more lebensraum?

Or, if you’d prefer to keep the matter closer to home: Who are we to question sharks or cougars, for whom we are food? In practice it’s difficult to negotiate with sharks and cougars, of course. But if even this is to have real moral significance, e.g. that creatures more capable of rational thought and mutual communication are morally better, we still need an objective inter-species account of morality. And suppose we found a particularly intelligent cougar, and managed some sort of communication; what would we be able to say? What reasons could we offer in defense of our claim that they ought not to eat us? Or is, ultimately, our moral authority in these conflicts no deeper than our superior weapons technology? If this is so, it’s hard to see why the superior weapons technology of the Nazi military wouldn’t justify their genocide of the Jews; and thus we run afoul of the Hitler Principle.

While specific moral precepts can and will depend upon the particular features of a given situation, and evolution surely affects and informs these circumstances, the fundamental principles of morality must be deeper than this—they must at least have the objectivity of scientific facts; in fact I think we can go further than this and say that the core principles of morality are in fact logical truths, the sort of undeniable facts that any intelligent being must accept on pain of contradiction or incoherence. Even if not trivially obvious (like “2+2=4” or “a triangle has three sides”), logical and mathematical truths are still logically undeniable (like “the Fourier transform of a Gaussian function is a Gaussian function” or “the Galois group of some fifth-order real polynomials has an acyclic simple normal subgroup” or “the existence of a strong Lyapunov function proves that a system of nonlinear differential equations has an asymptotically stable zero solution”. Don’t worry if you have no idea what those sentences mean; that’s kind of the point. They are tautologies, yes, but very sophisticated tautologies). The fundamental norms must be derivable by logic and the applications to the real world must depend only upon empirical facts.

The standard that moral principles should be scientific or logical truths is a high bar indeed; and one may think it is unreachable. But if this is so, then I do not see how we can coherently discuss ethics as something which makes true claims against us; I can see only prudence, instinct, survival or custom. If morality is an adaptation like any other, then the claim “genocide is wrong” has no more meaning than “five fingers are better than six”—each applies to our particular evolutionary niche, but no other. Certainly the Extrans will not be bound by such rules, and it is hard to see why cougars should be either. There may still be objectively valid claims that can be made against our behavior, but they will have no more force than “Don’t do that; it’s bad for your genes”. Indeed, I already know that plenty of things people do are (at least potentially) bad for their genes, and yet I think they have a right to do them; not only the usual suspects of contraception, masturbation and homosexuality, but indeed reading books, attending school, drinking alcohol, watching television, skiing, playing baseball, and all sorts of other things human beings do, are wastes of energy in purely Darwinian terms. Most of what makes life worth living has little, if any, effect at spreading our genes.

Naive moral Darwinism

PNRJ ethics, tribal paradigm , , , , , ,

Feb 23 JDN 2460730

Impressed by the incredible usefulness of evolutionary theory in explaining the natural world, many people have tried to apply it to ethical claims as well. The basic idea is that morality evolves; morality is an adaptation just like any other, a trait which has evolved by mutation and natural selection.

Unfortunately the statement “morality evolves” is ambiguous; it could mean a number of different things. This ambiguity has allowed abuses of evolutionary thinking in morality.

Two that are particularly harmful are evolutionary eugenics and laissez-faire Darwinism, both of which fall under an umbrella I’ll call ‘naive moral Darwinism’.

They are both terrible; it saddens me that many people propound them. Creationists will often try to defend their doubts about evolution on empirical grounds, but they really can’t, and I think even they realize this. Their real objection to evolution is not that it is unscientific, but that it is immoral; the concern is that studying evolution will make us callous and selfish. And unfortunately, there is a grain of truth here: A shallow understanding of evolution can indeed lead to a callous and selfish mindset, as people try to shoehorn evolutionary theory onto moral and political systems without a deep understanding of either.

The first option is usually known as “Social Darwinism”, but I think a better term is “evolutionary eugenics”. (“Social Darwinism” is a pejorative, not a self-description.) This philosophy, if we even credit it with the term, is especially ridiculous; indeed, it is evil. It doesn’t make any sense, either as ethics or as evolution, and it has led to some of the most terrible atrocities in history, from forced sterilization to mass murder. Darwin adamantly disagreed with it, and it rests upon a variety of deep confusions about evolutionary science.

First, in practice at least, eugenicists presumed that traits like intelligence, health, and even wealth are almost entirely genetic—when it’s obvious that they are very heavily affected by the environment. There certainly are genetic factors involved, but the presumption that these traits are entirely genetic is absurd. Indeed, the fact that the wealth of parents is strongly correlated with that of their children has an obvious explanation completely unrelated to genetics: Inheritance. Wealthy parents can also give their children many advantages in life that lead to higher earnings later. Controlling for inherited environment, there is still some heritability of wealth, but it’s quite weak; it’s probably due to personality traits like conscientiousness, ambition, and in fact narcissism which are beneficial in a capitalist economy. Hence breeding the wealthy may make more people who are similar to the wealthy; but there’s no reason to think it will actually make the world wealthier.

Moreover, eugenics rests upon a confusion between fitness in the evolutionary sense of expected number of allele copies, and the notion of being “fit” in some other sense, like physical health (as in “fitness club”), socially conformity (as in “misfits”) or mental sanity (as in “unfit to serve trial”). Strong people are not necessarily higher in genetic fitness, nor are smart people, nor are people of any particular race or ethnicity. Fitness entails the probability of one’s genes being passed on in a given environment—without reference to a specific environment, it says basically nothing. Given the reference environment “majority of the Earth’s land surface”, humans are very fit organisms, but so are rats and cockroaches. Given the reference environment “deep ocean”, sharks fare far better than we ever will, and better even than our cousins the cetaceans who live there. Moreover, there is no reason to think that intelligence in the sense of Einstein or Darwin is particularly fit. The intelligence of an ordinary person is definitely fit—that’s why we have it—but beyond that point, it may in fact be counterproductive. (Consider Isaac Newton and Alan Turing, both of whom were geniuses and neither of whom ever married or had children.)

There is milder form of this that is still quite harmful; I’ll call it “laissez-faire Darwinism”. It says that because natural selection automatically perpetuates the fit at the expense of the unfit, it ultimately leads to the best overall outcome. Under laissez-faire Darwinism, we should simply let evolution happen as it is going to happen. This theory is not as crazy as evolutionary eugenics—nor would its consequences be as dire—but it’s still quite confused. Natural selection is a law of nature, not a moral principle. It says what will happen, not what should happen. Indeed, like any law of nature, natural selection is inevitable. No matter what you do, natural selection will act upon you. The genes that work will survive, the genes that fail will die. The specifics of the environmental circumstances will decide which genes are the ones that survive, and there are random deviations due to genetic drift; but natural selection always applies.

Typically laissez-faire Darwinists argue that we should eliminate all government welfare, health care, and famine relief, because they oppose natural selection; but this would be like tearing down all skyscrapers because they oppose gravity, or, as Benjamin Franklin was once asked to do, to cease installing lightning rods because they oppose God’s holy smiting. Natural selection is a law of nature, a fundamental truth; but through wise engineering we can work with it instead of against it, just as we do with gravity and electricity. We would ignore laws of nature at our own peril—an engineer who failed to take gravity into account would not make very good buildings!—but we can work with them and around them to achieve our goals. This is no less true with natural selection than with any law of nature, whether gravity, electricity, quantum mechanics, or anything else. As a laser uses quantum mechanics and a light bulb uses electricity, so wise social policy can use natural selection to serve human ends. Indeed, welfare, health care, and famine relief are precisely the sort of things that can modulate the fitness of our entire species to make us all better off.

There are however important ways in which evolution can influence our ethical reasoning, which I’ll talk about in later posts.

The real source of the evolution debate, part 2

PNRJ Logic of Kindness , , , , , , , , , , , ,

As I discussed in my last post, the propositions that people really object to are not evolution per se. They are distinct but conceptually related ideas, such as adaptationism, common descent, animalism, abiogenesis, and atheism.

In my last post I dealt with adaptationism and common descent; now its time for animalism, abiogenesis, and atheism.

Animalism

Next we must consider animalism, the proposition that humans are not “special”, that we are animals like any other. I’d like to distinguish two forms of animalism which are quite different but often confused; I will call them weak animalism and strong animalism. The former is definitely true, but the latter doesn’t make any sense. Weak animalism is the observation that human beings have the same biological structure as other animals, and share a common ancestry and many common traits—in short, that humans are in fact animals. We are all born, we all die; we all breathe, we all eat, we all sleep; we all love, we all suffer. This seems to me a completely unassailable observation; of course these things are true, they are essential to human nature, and they are a direct consequence of our kinship with the rest of the animal domain. Humans are not rocks or plants or empty space; humans are animals.

On the other hand, strong animalism is the claim that because humans are animals, we may (or should) “act like animals”, stealing, raping, murdering, and so on. It is true that all these behaviors, or very close analogues, can be observed in the animal domain; but at the same time, so can friendship (e.g. in chimpanzees), affection (e.g. in penguins), monogamy (e.g. in gerbils), and many other behaviors. The diversity of behaviors in the animal domain is mind-bogglingly huge. There are animals that can sever and regrow limbs and animals that can infest and control other animals’ minds.

In the only sense in which we are “just animals”, the fact justifies no moral claims about our behavior. This matter is not a trivial quibble, but a major factor in the evolution debate: Intelligent Design proponents made a similar complaint when they objected to Bloodhound Gang’s song “The Bad Touch” which includes the line, “You and me baby we ain’t nothin’ but mammals // So let’s do it like they do on the Discovery Channel”. This may make for entertaining music (and I’ve no objection to sex or even promiscuity and seduction per se), but it is highly fallacious reasoning, and it’s clearly hurting the public understanding of science. If you insist on saying that humans are “just animals”, you should be very clear about what this means; I much prefer to remove the condescending “just” and say “humans are animals”. For to say humans are just animals would be like saying the Earth is just a planet, or love is just a chemical reaction. If all you mean is that the example is an instance of a category, you don’t need the “just”; by saying “just”, you clearly are trying to assert some sort of equivalence between members of the category, one that would deflate the status of the particular example. Yet if you have to say it, it probably isn’t true; no one would point at a random rock and say “this is just a rock”—instead you point to the Earth and say “this is just a rock”, when in fact it is a very special rock. Humans are a very special animals, the Earth is a very special planet, and love is a very special chemical reaction (closely tied to that most mysterious of chemical reactions, consciousness). We are members of one vast animal family—indeed, one vast family of life—but we are most definitely the wisest and most powerful member.

I’m honestly not sure what I would do if I tried to “act like an animal”; I suppose I would be born, breathe, eat, sleep, love, suffer and die—but I was going to do these things anyway, whether I wanted to or not. Indeed, by weak animalism, humans are animals, and so by acting like human beings we are in fact acting like animals—the animal Homo sapiens.

Abiogenesis

Next comes abiogenesis, the proposition that living things came from nonliving things. Well, where else would they come from? The only way to deny this proposition is to say that living things always existed. (If God made life, he would have done so by being a living thing that always existed.) The problem with this idea is that it doesn’t really explain where life comes from, it only pushes its origin back into the infinite past. Scientists are making progress in using nonliving chemicals to produce replicating entities that are very similar to life, and inn 2010 scientists created the first all-synthetic bacterium, but to do it they had to use pre-existing bacteria to set up the reactions. This lends credibility to the idea that life came from nonlife, but in fact even this wouldn’t conclusively demonstrate abiogenesis; it would prove that life can arise from nonlife, but that doesn’t mean it did originally. The truth is, we really don’t understand much about the origin of life, and even less about the origin of the universe; but this does nothing to undermine evolution or even common descent. No one doubts the existence of gravity simply because we don’t know what caused the Big Bang!

Atheism

Finally, and most controversially, there is atheism. Theism is belief in a superhuman being that responds to prayers and performs miracles; atheism is the negation of theism. This is all atheism means; if you think it means something more than this—absolute knowledge that there cannot be a creator being, or no ultimate foundation for morality, or no meaning to existence, or whatever else—that isn’t atheism. An atheist is someone who doesn’t believe in a personal divinity, someone who says that there are no superhuman beings that intervene in our lives. This is a fairly strong claim in itself, since if correct, atheism implies that religion as we know it—prayer, rituals, miracles, holy books—is utterly false. Deep philosophical religion, like that practiced by Einstein or Kant, remains intact; but the religion of churches, mosques and temples is completely undermined.

Evolution doesn’t imply atheism, but it does support it, in the following sense: Evolution answers the question of “Where did we come from?” without requiring God. Even before we knew about evolution, religion wasn’t a very convincing answer to that question; but we didn’t really have a better one—and now we do.

Yet atheism is clearly correct. This is something we can infer directly from a large body of scientific evidence. I’ve already addressed this topic in previous posts, so I’ll be brief this time around.

Maybe there is a kind of religion that could be reconciled with science; but it’s not a theistic religion. Perhaps there is a God who made the whole of the universe, set it running in perfect harmony to achieve some divine plan. This is called deism, and it’s a scientifically respectable position. But then, it is senseless to pray, since God isn’t going to change the divine plan on behalf of tiny creatures on a backwater planet of a backwater star in a backwater galaxy. It is plainly wrong to call such a being “he” or even “He”, since no being so vast and powerful could ever be properly described in the petty terms of a biological male—it would be like saying that gravity has testicles, energy conservation has a beard, or causality has a Y chromosome. I’m not sure we can even fairly say that God is a conscious being, for consciousness as we know it seems too vulgar a trait to assign to an entity of such vastness. In fact, the theologian Paul Tillich thought even existence a concept insufficient to describe the divine. It is foolish to look to ancient books to understand God, for its work is written from horizon to horizon in the fabric of the universe, and these ancient books are but pale shadows of its grandeur. It is naive to suppose that we are special beings created in God’s image, for God has made many millions of species on this planet, and probably countless more on other distant planets; furthermore, God’s process of production favors insects and bacteria and requires massive systematic death and suffering.

And even once we have removed everything we knew of religion, even this truncated theology suffers from an egregious flaw: Such a creator offers us no evidence of its existence. A deistic God is indistinguishable from the universe itself, definitely in practice and perhaps even in principle. I don’t really see the point in using the word “God” when the word “nature” captures what we mean much better. Saying “God is vaster than we can imagine, and of course by `God’ I mean the universe” strikes me as like saying “The Sun is powered by magical unicorn love, and of course by `magical unicorn love’ I mean nuclear fusion.”

And theism, religion as we know it, is philosophically and scientifically bankrupt. Imagine an airline pilot who lets go of the controls and prays to God to fly the plane; imagine a surgeon who puts down the scalpel and prays to God for the patients to be healed. That’s the sort of thing we would do if theism were true. It would make sense to do these things—it would be rational to do these things—under the presumption that there is a God who answers our prayers. You can’t escape this; if it makes sense to pray for your sick grandmother, then it doesn’t make sense for her to take medicine—because if God is in control, then chemistry isn’t. The fact that hardly anyone really would resort to prayer when an obvious and effective scientific alternative is available (and the fact that people who do are considered fanatical or even insane) clearly shows that theism is bankrupt, and that hardly anyone believes it confidently enough to actually live by it. No one except the craziest fanatics believes in God the way they believe in gravity.

I’m sure this book will be perceived as yet another “angry atheist” “attacking” “religious people”; on the contrary, I am a respectful and reflective atheist criticizing theistic religion. I respect religious people; I do not respect theistic religion. Indeed, I respect religious people too much to let them go on believing such ridiculous things. What glorious powers of human reason are wasted on such nonsense! If you believe in the subtle, abstract, inscrutable God of Einstein or Spinoza, very well. We disagree only about the most abstract matters, almost at the level of semantics (what you call “God” I prefer to call “nature”). Our beliefs and values are not only reconcilable but nearly identical.

On the other hand if you believe in a magical personal God, a God who writes books and answers prayers, then my criticism is indeed directed at your beliefs; I think you are mistaken, gravely, dangerously mistaken.

Atheism is a scientific fact.

Conclusion

Evolution is a fact. The Modern Synthesis of genetics and natural selection is among the most certain scientific theories ever devised; it is the unified field theory of life on Earth. The following claims may be controversial in our society, but they are also scientific facts: Living things are adapted to their environment by natural selection; all life on Earth is descended from a common ancestor; humans are animals; life arose by natural processes; and theistic religion is false. You can accept these facts, or else you can live in denial.

Yes, in principle evolution is a theory that can be doubted, but in principle everything in science is a theory that can be doubted. If you want certain, undeniable truths, you will need to stay with logic and mathematics—and even then, you’ll need to be careful about your axioms. Otherwise, you must always be open to a thin sliver of uncertainty, a sliver that should be no larger for evolution than for gravity or photosynthesis. (Of the three, gravity is by far the least-understood.)

The convergence of scientific evidence in favor of evolution, a 4.5-billion-year-old Earth, genetics, natural selection, common descent, adaptationism, weak animalism, and yes, even atheism, is so incredibly massive that we’d have to give up half of science to abandon these things. Any revisions we do make in the future will necessarily be minor, leaving the core of truth intact.

To doubt that rubidium decays into strontium at the same rate now it did a million years ago, you must explain how the fundamental laws of nuclear physics that we have verified to twelve decimal places are incorrect.

To doubt that cetaceans evolved from land mammals, you must explain why they breathe air instead of water and swim vertically rather than horizontally, unlike nearly everything else in the sea.

To believe in microevolution but not macroevolution, you must think that there is some mysterious force that prevents what has happened 100 times from happening an additional 100,000 times for the same reasons—for, if repeated many times, a 0.01% systematic change per century, a darwin of evolution (lowercase for a unit of measure, like the newton of force or the weber of magnetic flux), is more than enough to account for the transition from archaea to eukaryotes over 3 billion years, and vastly more than is needed to account for the transition from apes to humans over 5 million years. In fact, observed rates of evolution in the short term have reached the level of kilodarwins, thousands of darwins.

To doubt that life on Earth has changed and diverged over time you must ignore the most obvious facts about a remarkably rich and well-organized fossil record. There are no rabbits in Precambrian layers. There are no trilobites in Mesozoic layers. There are no primates in the Jurassic, and no sauropods in the Tertiary. There have never been a human fossil and a dinosaur fossil found in the same rock. Creationists like to claim that the fossil record sorted itself by size and lifestyle (as here), but in fact there are large and small, land and sea, in pretty much every layer of the fossil record—just not the same ones, because the organisms in lower layers died off and were replaced by the organisms in higher layers. Pterodactyls look a lot like a birds, come in roughly the same size ranges as birds, and seemed to live similar lifestyles, but you’ll never find the two buried together. Looking at the fossils, you can’t help but infer evolution; if God made the fossils, he must have wanted us to believe in evolution.

The real source of the evolution debate, part 1

PNRJ Logic of Kindness , , , , , , , , , , ,

Feb 9 JDN 2460716

The last few posts have been about evolution; but everything I’ve said in them has been very technical and scientific, and I imagine it is not very controversial or offensive to anyone. In fact, I would guess that anyone who believes in Creationism, upon reading my definition of evolution as “change in allele distribution in a population”, was thinking, “Of course we believe in that. But that’s not evolution.” Actually it is; evolution is change in allele distribution in a population. What people are objecting to isn’t really evolution.

There are however several propositions that people do object to, which are conceptually related, but not strictly implied by evolution. They are adaptationism, common descent, animalism, abiogenesis, and atheism respectively. They are all true—and in what follows I will offer a defense of each—but they are not necessarily entailed by evolution or the Modern Synthesis, and so they should be considered separately on their own merits. This post will deal with adaptationism and common descent, and I’ll save the others for a later post.

Adaptationism

Adaptationism is the principle that living organisms have the traits they do because these traits are adaptive, that is, that they are beneficial to fitness. It’s obvious that this isn’t completely true in every case; whales have hipbones despite having no apparent use for them, and the human appendix seems mostly useful for collecting toxins and occasionally exploding. There are also limits to how much an organism can change given its current structure; the emerging field of developmental evolutionary biology, or evo-devo, seeks to characterize these limits more precisely.

But in general, adaptationism is an incredibly powerful principle, one which makes sense of the diversity and complexity of life on Earth in a way no other theory can. Natural selection predicts that organisms will become more and more adapted over time; adaptationism is based on the fact that we have had plenty of time to adapt really, really well. In fact, it can be argued that adaptationism is really what evolutionary theory is about, that all this business about changes in allele distributions is useful but not really the point of the enterprise.

When we look at the world, we see that living things are extremely complex and well-suited to their environments; theologians used to say (in fact some still do) that this was evidence that living things were designed by a perfect God.

The problem with this argument was exposed almost immediately by David Hume: If complex things need designers, aren’t designers even more complex than what they design? But then, the designer needs a designer-designer, and the designer-designer needs a designer-designer-designer, and so on into an infinite regress! Another problem with this sort of Intelligent Design thinking is that it cannot explain the cases when adaptationism fails—in particular, why do so many species go extinct? Recently a theory of “Intelligent Recall” was proposed for this purpose; but this forces us to think of our designer as no more intelligent than a financial analyst or an automobile engineer! What kind of God would make mistakes in design?

And now we know better: The remarkable complexity and fitness of living organisms can be entirely explained by adaptationism. When we ask why dolphins have fins, why birds have wings, why centipedes have so many legs, why snakes are so long, or why humans have such enormous brains, adaptationism gives us the answer: organisms have these traits because having these traits benefited their ancestors. In some cases it’s pretty obvious how this would work (having fins lets dolphins swim faster, swimming faster has obvious benefits in catching fish and escaping sharks, so dolphin ancestors with more fin-like limbs survived better); in others we’re still working on the specifics (there is as yet no consensus on how humans got so incredibly smart compared to other animals); but in general adaptationism has explained a huge body of data that we couldn’t account for any other way.

Common descent

Common descent is the proposition that all living organisms on Earth are descended from a common ancestor. This implies, in particular, that human beings share a common ancestor with other animals. The former is strictly stronger, and not quite as certain; at least in principle it could be that some broad classes of organism do not share a common ancestor, but nonetheless it would still be quite clear that humans share a common ancestor with chimpanzees. In practice nearly all biologists agree with the strongest form of common descent, that all living organisms on Earth share a common ancestor. Recently the biochemist Douglas Theobald mathematically compared this strongest form of common descent (universal common descent) with several other models of phylogenetic history, finding that universal common descent was the most probable result by a factor of at least 102000—a 2001-digit number. That is, scientists are 99.999,999,999,999,999,999… (on with 1,980 more nines!) percent sure that universal common descent is right. This is not hyperbole; it is mathematically precise. At this point any sliver of uncertainty left in universal common descent needs to apply to all of our fundamental knowledge of physics and chemistry; in order to be wrong about this, we’d need to be wrong about everything.

How are we so sure? Nature presents us with a very consistent pattern of observations that simply make no sense any other way. Traits in living things (and, we are increasingly finding, genes) have distinct patterns, structural similarities that exist between species irrespective of their lifestyle; we call these similiarities homologues. (Similarities that are due to lifestyle—e.g., both dolphins and fish have fins—are called analogues.) Dolphin skeletons are more like dog skeletons than they are like fish skeletons, even though dolphins live more like fish. Bat skin is more like human skin than like bird skin, even though bats live more like birds. The most parsimonious explanation is that these traits were passed on from some common ancestor—that dolphins and dogs have similar skeletons because dolphins and dogs are actually genetically related somehow, and they differ from fish because they are more distantly related.

Once we began to understand DNA, we became able to detect even more compelling homologues. Many kinds of mutation are completely ineffectual; some involve a change to DNA that doesn’t do anything, others swap out two amino acids that are essentially the same; in fact because of the way genes code for amino acids, it’s possible to have a change in a gene that isn’t reflected in the resulting protein at all. All of these changes have no effect on the organism, but they are still passed on to offspring. When you find two organisms that have the same trait (e.g. bats and birds both have wings), if that trait does something important (lets you fly), then maybe it’s just a similarity in lifestyle; if that happens we call it convergent evolution. But when we’re looking at a DNA sequence that doesn’t do anything, lifestyle can’t be the reason—it must be either common ancestry or pure coincidence. Statistical analysis can rule out pure coincidence, and then we are left with only one possibility: common descent. A third option often proposed by Creationists simply doesn’t work: A common designer of sharks and dolphins would not give one a cartilaginous skeleton and gills and the other a bony mammalian skeleton and lungs. There is no reason for dolphin skeletons to be more like dog skeletons than shark skeletons—except that dogs and dolphins share closer common ancestry to each other than they do to sharks.

There are thousands of traits and genes that we can use to assess these relationships. When we do this, we find a remarkably consistent organizational structure, a pattern of a few common ancestors diversifying into a wide variety of descendants—it looks a bit like a tree, so we call it a phylogenetic tree. In some cases there is ambiguity about which species are more closely related, and we need to gather more evidence. This is a normal part of evolutionary biology research.

One thing is not disputed: Humans share a common ancestor with apes. This is simply too obvious from the morphological and genetic homologues. Human and chimp DNA coincides 95-98\%, depending on how you count insertions and deletions.

A standard measure of genetic distance is the Nei distance; a larger Nei distance implies more genetic differences, which in turn suggests that the common ancestor was further in the past. (Exactly how it’s calculated is a bit too technical for this post.)

Humans and chimps have a Nei distance of 0.45. This similarity between humans and chimps represents a closer similarity than that between dogs and foxes, who differ by a Nei distance of 1.1. Almost anyone can see that dogs and foxes are related animals; so why is it so hard to believe that humans and chimps are related too?

Creationists often claim that we never find the transitional forms predicted by evolutionary theory, but this is simply not true. We do in fact see many transitional forms; feathered dinosaurs mark the transition from reptiles to birds, ambulocetids mark the transition from land mammals to cetaceans, therapsids mark the transition from reptiles to mammals, and a huge variety of hominids marks the transition from apes to humans. It’s important to understand what this means: transitional forms are not bizarre combinations of their descendant organisms, but fully-functional lifeforms in their own right that have descendants very different from one another. Just as your grandparents are not a combination of half of you and half of your first cousin, common ancestors are not simply half-and-half combinations of their descendant organisms. Ambulocetids are not half-deer/half-dolphin, they are somewhat deer-like yet somewhat dolphin-like mammals whose ancestors were on average slightly more deer-like and whose descendants were on average slightly more dolphin-like. Different traits changed at different times, generations apart: Ambulocetids began to swim before they lost their legs, and even modern dolphins haven’t lost their lungs or hipbones.


This is such a deep, marvelous truth that Creationists are missing out on: All life on Earth is part of one family. We are kin with the dogs and the cats and the elephants, with the snakes and the lizards and the birds, with the beetles and the flies and the bees, even with the flowers and the bushes and the trees.

Defining evolution

PNRJ Logic of Kindness, tribal paradigm , , , , , , , , ,

Feb 2 JDN 2460709

In the last post I said I’d explain the basics of evolution, then went into a bunch of detail about genetics. Why all this stuff about DNA? Weren’t we supposed to be talking about evolution? Yes—but it’s impossible to truly understand evolution without understanding DNA. This unity between genetics and evolution is called the Modern Synthesis, and it is the unified field theory of the life sciences. It’s quite different from what Darwin invented in 1859, but the fundamental insights were his; the Modern Synthesis is a body of flesh over the skeleton of Darwinian evolution. Now that I have explained the basics of DNA, it is time to discuss evolution itself.

The fundamental unit of evolution is the gene. (Darwin, among others, insisted that the fundamental unit of evolution is the organism, because it is organisms that are born and die. There is some truth to this, but given the presence of phenomena like kin selection and genetic drift, we also need to consider genes themselves. Richard Dawkins makes a distinction between “replicators” (genes) and “vehicles” (organisms) that makes a great deal of sense to me—both are necessary parts of the same system, and it’s a little silly to ask which is “more fundamental”.) The fundamental unit of evolution is not the population or the species; it is populations that evolve, but they evolve by natural selection acting upon individuals and genes. Natural selection is not sensitive to “the good of the species”; it is only sensitive to the good of the organism and the good of the gene.

A gene is a section of DNA that, when processed by the appropriate proteins, produces a particular protein. Most DNA is not in the form of genes. The majority of DNA has no effect—you can change it without affecting the organism—and most of the rest is involved in regulating the genes, not in producing proteins. Yet, genes are the recipes by which we are made. Human beings have genes for hemoglobin that oxygenates our blood, genes for melanin that pigments our skin, genes for serotonin that transmits signals in our brains, genes for keratin that makes up our hair, and about 46,000 other genes that produce other proteins (the Human Genome Project is still working on the exact number). An allele is a particular variant of a gene which produces a particular variant of the resulting protein. Alleles in melanin genes give different people different colors of skin; a particular allele in a hemoglobin gene gives some people sickle-cell anaemia.

When the distribution of alleles in a population changes, that is evolution. Yes, that’s all “evolution” means: Changes of distribution in alleles in a population. When a baby is born, that’s evolution. When a person dies, that’s evolution. This is what we mean when we say that evolution is a fact; it is a fact that alleles do change distribution in populations. Individuals do not evolve, populations evolve. You will never see a dog turn into a cat, nor an ape to a human. You could see, if you were watching for millions of years, a population of animals that started very dog-like and got increasingly cat-like with each generation, or a population of animals that started very ape-like and got increasingly human-like with each generation. Even these latter are not necessary occurrences; under different environmental circumstances, the same genes can evolve in completely different directions.

Fitness is the expected number of copies that an allele is likely to produce in the next generation.(There are a few subtly different ways of defining fitness; the one I prefer is the expected value of the number of copies of a given allele in the next generation. The fitness f of an allele a at generation t is given by the expectation of the number n of copies of that allele in that population at generation t+1: f(a,t) = E[n(a,t+1)]This is an \inclusive fitness measure, which accounts for kin selection better than exclusive fitness measures like “predicted grandchildren” or “expected number of reproductively-viable offspring”. In practical terms these generally give the same results; but when they don’t, the inclusive measure is to be preferred.)

Fitness is a probabilistic notion—alleles with high fitness are likely to be passed on, but this is not guaranteed. “Survival of the fittest” ultimately just means that genes that are likely to make many copies are likely to have many copies. It has been said that this is a tautology, and indeed it is; but so is the Pythagorean Theorem. Some tautologies are useful, and all tautologies are undeniably true.

What causes evolution? Organisms are born, reproduce, and die. Any time this happens, it changes the distribution of alleles in the population—it is evolution. If there was a reason why the ones who lived lived and the ones who died died, then the actual number of copies of each allele in the population will reflect the fitness of those alleles; this is called natural selection. On the other hand, if it just happened by chance, then the distribution of alleles won’t match the fitness; this is called genetic drift. Examples of each: Trees are tall, giraffes eat leaves, so giraffes with longer necks get more food and live longer—that’s natural selection. A flood rips through the savannah and kills half of the giraffes, and it just happens that more long-necked than short-necked giraffes die—that’s genetic drift. The difference can be subtle, since sometimes we don’t know what the reasons are; if it turned out that there was some reason why floods are more likely to kill long-necked giraffes (they can’t swim as well?), then in fact what we thought was genetic drift was really natural selection. But notice: Natural selection is not chance. Natural selection is the opposite of chance. If evolution happens by chance, that’s genetic drift. Natural selection is evolution that happens for a reason.

Natural selection changes populations, but what causes them to separate into distinct species? Well, a species is really a breeding population—it is a group of organisms that regularly interbreeds within the group and does not regularly interbreed outside the group. In most cases, breeding between species is actually impossible; but in many cases it is simply rare. Indeed, there is a particularly interesting case called a ring species, in which interbreeding possibilities rest on a continuum rather than being sharply delineated. In a ring species, there are several distinct populations for which some can interbreed easily, others can interbreed with difficulty, and others can’t inbreed at all. A classic case is the Ensatina salamanders who live in the Central Valley in California. There are nineteen populations, and each can interbreed with its adjacent populations—but the two populations at the far ends cannot interbreed. Ensatina eschscholtzii eschscholtzii can interbreed with E.e. croceater, which can interbreed with E.e. oregonensis, and so on all the way to E.e. klauberi—but E.e. eschscholzii on one end can’t interbreed with E.e. klauberi on the other end. Are they different “species”? It’s difficult to say. If all the intermediates died out, we would call them different species, Ensatina escholzii and Ensatina klauberi; but in fact genes do sometimes pass between them, because they can both interbreed with the intermediates. Really, the concept “species” fails to capture the true complexity of the situation.

This is not a problem for evolutionary theory—it is a prediction of evolutionary theory. We should expect to see new species occasionally forming, and while they are in the process of forming there should be many intermediates that aren’t yet distinct species. Evolution predicts gradual divergence, and sometimes we are lucky enough to see that divergence in process.

Natural selection can only act upon alleles that already exist; it chooses the best out of what’s available, not the best that could possibly exist. This is why dolphins breathe air instead of water; breathing water would be much better for their lifestyle, but no dolphin has yet been born who can breathe water. The alleles aren’t there, so natural selection cannot act upon them. If a mutant dolphin is someday born who can breathe water, as long as they don’t suffer from other problems as a result of their mutation, they are likely to live a long time and have lots of offspring; in a hundred generations perhaps water-breathing dolphins would form a new species, or even replace air-breathing dolphins. And notice how short a time that is: 100 generations of dolphins is only about 1000 years. We could watch this happening in historical time. If it had happened a million years ago, the fossil record would probably never show the intermediate forms. This is why we don’t see transitional forms between closely-related species; because the differences are so subtle, the necessary changes can occur very rapidly, in too few generations to ensure fossilization.

Indeed, monogenic traits—those that can be changed by a single mutation—never produce transitional forms. There is a single gene for sickle-cell anaemia in humans; we should not expect to see people with “30\% sickle-cell anaemia”, because there are only three options: you either have no copies of the sickle-cell allele (normal), you have one copy (sickle-cell trait), or you have two copies (sickle-cell anaemia). In fact, in this particular case, the one-copy variant isn’t even mild anaemia; it is a generally healthy non-anaemic state that offers protection against malaria. There is a single gene for six fingers in humans. Two copies gives you six fingers; one copy doesn’t do anything. Even if we had access to every individual organism that ever lived, we still wouldn’t see transitional forms for monogenic traits. Given that we actually have fossils of less than one in ten billion organisms that ever lived, it’s not surprising that most evolutionary changes leave no mark in the fossil record.

Furthermore, it’s important to understand that natural selection, even when there is plenty of variation to act on, does not produce perfectly-adapted organisms. It only produces organisms that are good enough to survive and pass on their alleles. In fact, there can be multiple fit alleles of the same gene in a population—all different, perhaps even some better than others, but each good enough to keep on surviving.

Indeed, the fitness of one allele can increase the fitness of another allele, in a number of different ways. The most morally-relevant ones only make sense in terms of game theory, so I will wait until later posts to get into them, but there are a few worth mentioning here. The first is co-evolution. Organisms evolve to suit their environments—but part of an organism’s environment consists of other organisms. Bees would not function if there were no flowers—but nor would flowers function without bees. So which came first, the bee or the flower? Neither. Ancient ancestors of each evolved together, co-evolved, the proto-flowers growing more flower-like as the proto-bees grew more bee-like, until finally an equilibrium was reached at the bees and flowers we see today.

Another way that organisms can affect the evolution of other organisms is through frequency-dependent selection, in which the fitness of a given allele depends upon the distribution of other alleles of the same gene. The most important case of frequency-dependent selection is in sex dimorphism, the differences between sexes within a species. If there are more males than females, the fitness of females goes up—it pays to be female; you’ll get your choice of males. Conversely, if there are more females than males, it pays to be male. Hence, over time, sex distributions reach an equilibrium at 50% male and 50% female, which has happened in almost every species (eusocial insects are the only major exception, and it’s due to their weird genetics). There are other cases of frequency-dependent selection as well; for instance, in stag beetles (Lucanidae), there are three kinds of males, called “alpha”, “beta”, and “gamma”. Alpha males have large horns and fight heavily with other alpha males; they risk being killed in the process, but if they win the fight, they get all the best females. Beta males have short horns and only fight other beta males; this limits their mating pool, but prevents them from being killed by alpha males. Finally, gamma males look just like females and will occasionally sneak past an alpha male and mate with his females. This is frequency-dependent selection because the success of each strategy depends on the other strategies in a fashion similar to rock-paper-scissors. If gamma males become very common, beta males will become more successful, because they won’t get cheated the way alpha males do. If beta males become common, alpha males will become more successful, because they can beat beta males in fights. If alpha males become common, gamma males will become more successful, because they can cheat alpha males. In the long run, the system settles into an equilibrium with a certain fraction of all three types.

A third way alleles affect other alleles is in sexual selection; in sexual selection, the alleles of one sex affect the alleles of the other sex, because sexual compatibility has obvious advantages. For instance, when there are lots of alleles in peahens that make them attracted to big, colorful tails, there is a fitness advantage to being a peacock with a big, colorful tail. Hence, alleles for big, colorful tails in peacocks will be selected. But then, if all the males have big, colorful tails, there is a fitness advantage to being a female who prefers big, colorful tails, and so a positive feedback loop forms; the end result is peacocks with ridiculously huge, ridiculously colorful tails and peahens who love them for it.

Everything above is very technical and scientific, and I imagine it is not very controversial or offensive to anyone. In future posts, I’ll get into the stuff that really upsets people, the true source of controversy on evolution.