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.