Book Review: Why Evolution Is True (2009) by Jerry Coyne

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I read this book just to get an introduction before going to the heavier stuff. Not that I’m completely ignorant on the subject but I often find that going back to the basics is the best way to re-kindle and interest and as a launch pad for the heavier literature. The obvious choice for a non-expert would probably be Richard Dawkins, but I find his style a bit pompous; he sounds too much like the character Buzz Killington in Family Guy. So I settled for biologist and evolutionist zealot Jerry Coyne instead. He has a clear and simple albeit impersonal style like so many writers in Academia. Unlike many other biologists, he focuses on the theory and doesn’t get bogged down in a myriad of empirical facts, something that has always turned me away from reading books on biology; maybe it’s an aspergery trait of biologists, I don’t know.

Selection

He starts off with a presentation of the basic concepts of the theory, like natural selection, how gene variants in a population will become more or less frequent depending on whether they will promote survival and reproduction in a species. Then there is the less natural selection that is due to the fact that most species reproduce by sex rather than by cloning themselves. This means that we only pass on some gene variants to our offspring. Gene variants that aren’t good or bad can then become more or less common in a species just by random recombination, so-called genetic drift. It could also happen when a species dwindles to a very few individuals (called a bottleneck). If these individuals all happen to have pointy ears and this trait is neutral, then pointy ears it is. This random effect is not a big factor but it does happen.

Speciation

The other big thing is speciation: how every species ends either in extinction or by splitting into two new species. This means that the ancestral tree of all species is binary, and full of dead ends as most species become extinct without leaving any descendants. Speciation usually happens as populations of the same species are separated in different environments. A new environment will make new traits more adaptive, that is leading to survival and reproduction. And so the gene variants that cause these traits will become more common. This means that the populations become genetically less related. At some point they can’t interbreed anymore and the species has split. Unless Homo sapiens becomes extinct, we too will split eventually. I bet that will be awkward…

Evidence

The evidence for evolution can be found in many places. In spite of modern DNA technique, fossils remain an important clue to how life has evolved. We can date fossil by looking at what layer of rock it is located in, or by radioactive material that breaks down at a certain pace after the rock formed. Another dating method is based on the fact that the Earth’s rotation is slowing down so that days are getting longer and years are getting shorter – 380 million years ago, a year had 396 days and a day had 22 hours. Some organisms have growth markers for both day and year that are preserved in their fossil and can be dated this way.

What the fossil records tell us is that life has evolved, become more advanced and better adapted to various environments. When we go backwards in time we can find how tetrapods evolved into reptiles that evolved into birds and mammals. And all the fossils can be dated to the time period when they are supposed to be if evolution took place. That’s pretty hard evidence.

In a way art is like fossil - something alive in the mind of the artist that has been petrified and frozen in time. Art by Jenny Edlund. For more of her work just click the image.

In a way art is like fossil – something alive in the mind of the artist that has been petrified and frozen in time. Art by Jenny Edlund. For more of her work just click the image.

We can also find evidence in the form of vestiges, like the wings of ostriches. Both DNA and fossil records show that they descended (hehe) from flying birds. So at some point flying was not beneficial anymore and they started to evolve new traits. But wings can’t just disappear from one generation to the next, so in the case of the ostrich they represent a transition between the flying wing and whatever trait they will evolve into in the flightless existence. Why did it happen? One clue is that they are common on remote islands with few reptiles and mammals that could prey on them.

Or we have the hind legs of whales, small bones no longer connected to the rest of the skeleton, encapsulated in their bodies. They make no sense at all unless whales descend from land-living animals. Same goes for dolphins that have inactive olfactory receptors. Or our own genes for tails, also inactivated in most of us. And so on. Overall, Coyne presents this evidence well and makes a good case.

The Mystery of Sexual Selection

But when it comes to sexual selection, in which choice of mate decides the reproductive success of the individual, he fails to deliver a clear and reasonable explanation. Even Darwin had problems with this phenomenon. This type of selection is partly about male competition, the strongest walrus will knock out his competitors and mate with the females. That’s easy to understand because strength and endurance required to win these battles are heritable qualities that will then be passed on to the next generation. But in some cases, like peacocks, the males just show off gaudy traits like bright colors and large tail feathers and such. And for some reason the gaudiest win.

It seems that females (and in some species males) will choose whatever is novel and intense. You can glue some random blingy stuff on males and they will be transformed into desirable alphas. This makes less sense because unlike an alpha walrus who was selected for traits that enable him to search for food or fight off other animals, the gaudy traits are useless, even harmful as they reduce the animals mobility and attract predators. Or are they?

This, apparently, is what a real male looks like.

This, apparently, is what a real male looks like.

Coyne explains this as having to do with the fact that the sexes have different numbers and sizes of their gametes (eggs and sperm). But why did sexual reproduction become so common in the first place? The author says this is unclear. And why two sexes rather than three or five? And why the asymmetry of the gametes? Coyne says these are “messy” issues and just states these things as facts the reader will simply have to accept. I guess that saved him a lot of hard work, but it does nothing for the reader. But since the number of sexes and the asymmetry of gametes are facts, let’s move on and see if Coyne can explain sexual selection – and especially the weird gaudy traits that even Darwin was worried about.

Since the number of gametes is higher for males it means they can sire more offspring. The author exemplifies with the male record holder, a Moroccan emperor during the 1700s who had around 1000 children as opposed the female record holder, a Russian women (also living in the 1700s), who had 69 children. However, he fails to mention that women have hundreds of thousands of eggs so that doesn’t appear to be the limiting factor. It seems to me that the length of the pregnancy would be a more obvious reason why women can’t have a thousand children. He does mention that females have a larger investment in this way too but how does it relate to gametes?

But again, it is a fact that females are usually more invested and this means they have to be more picky regarding who they will mate with. But how do we go from that to the preference for gaudy traits? This is how Coyne explains it,

Males must compete to fertilize a limited number of eggs. That’s why we see the “law of battle”: the direct competition between males to leave their genes to the next generation. And that is also why males are colorful, or have displays, mating calls, bowers, and the like, for that is their way of saying “Pick me, pick me!” And it is ultimately female preference that drives the evolution of longer tails, more vigorous displays, and louder songs in males.

I can’t see how this explains the gaudy traits though. A female would always be better off with a male who does battle and wins over other males since this would be an indication of gene variants conferring strength and stamina. The bright colors and long tail feathers on the other hand impair the individual so that even if it’s somehow a proxy for health this would be largely cancelled by this impairment. The choice between a healthy male who is strong and mobile and a healthy male who is strong but attracts predators and has less mobility should be easy. Coyne mentions the American house finch as an example, how brightly colored males bring more food to their offspring, and how this might be an indication of health and it certainly gives females a direct advantage since lots of food increases the survival rate of the offspring. But this still doesn’t explain why she wouldn’t prefer a male that gets her lots of food without bringing predators in his wake. And do peacocks with large tail feathers that impair mobility bring more food too?

Coyne just fails miserably to explain this. And it’s even more disconcerting that there is so little evidence that gaudy males really produce more viable offspring – two studies to date. One of these is on frogs in which the males with the loudest call gets the females. But this is more of a physical display of strength than genuine gaudiness. This leaves us with one single study of peacocks in a semi-natural environment in Britain as the entire body of evidence. And then there is a number of studies that found no such effect; Coyne doesn’t say how many. But he does admit,

This belief, in the face of relatively sparse evidence, may partly reflect a preference of evolutionists for strict Darwinian explanations—a belief that females must somehow be able to discriminate among the genes of males.

This seems problematic, to say the least. Belief?

Debating Creationists

But even more problematic is the criticism of creationism that permeates this book. Obviously any creationist who accepts scientific method as the only way of understanding reality would have to concede that Darwin beats the Bible. But creationists are into metaphysics, they work under the assumption that there is an almighty creator – who created our ability to use scientific method in the first place. If this creator exists – and there is no way we can know – then all bets are off. Disproving God with science just isn’t science.

He also addresses the concern of evangelical author Nancy Pearcey and others who feel that the theory of evolution will undermine moral and cause social decay,

But Pearcey’s notion that these lessons of evolution will inevitably spill over into the study of ethics, history, and “family life” is unnecessarily alarmist. How can you derive meaning, purpose, or ethics from evolution? You can’t.

He also mentions congressman Tom Delay’s idea that the Columbine massacre was inspired by the theory of evolution, implying that this is nonsense. But he fails to mention the fact that one of the perpetrators, Eric Harris, entertained fantasies of superiority and of killing retarded people. At the day of the massacre he wore a t-shirt with the text “natural selection.” And Finnish school shooter Pekka-Eric Auvinen called himself a social Darwinist and who declared that, “I, as a natural selector, will eliminate all who I see unfit, disgraces of human race and failures of natural selection.”

Self-proclaimed social darwinist Pekka-Eric Auvinen.

Mass murderer and self-proclaimed social darwinist Pekka-Eric Auvinen.

Still Coyne claims that evolution doesn’t tell us to behave like these guys and that most human behavior isn’t even dictated by evolution. That may or may not be true, but that’s not the issue – it’s about how human behavior may be influenced by the theory per se, a cultural influence. Maybe some people will become inspired to acts of violence by the idea of natural selection.

And perhaps the author himself can’t handle the theory of evolution. When discussing “the sticky question of race” he admits that race is not a social construct since it is defined as differences on certain traits between populations of the same species. But he insists that the differences between races don’t amount to much since we left Africa so recently,

At the genetic level, then, human beings are a remarkably similar lot. That is just what we would expect if modern humans left Africa a mere 60,000 or 100,000 years ago.

And while he acknowledges that different groups have different intelligence and behavorial traits, he says we can’t know if this is due to evolution or not because we can’t conduct the research for ethical reasons,

Such studies require controlled experiments: removing infants of different ethnicity from their parents and bringing them up in identical (or randomized) environments. What behavioral differences remain would be genetic. Because these experiments are unethical, they haven’t been done systematically, but cross-cultural adoptions anecdotally show that cultural influences on behavior are strong.

So we have all these creative ways of dating fossil but when we come to a politically sensitive issue there is one and only one way to find evidence – and that’s forbidden for ethical reasons, so we shall never know. Personally, I think that if you can believe this nothing-to-see-move-along-folks trick then maybe belief is your forte, in which case you may prefer the Bible to this book.

Still, for some odd reason the author implies that anectdotal evidence of cross-cultural adoptions could give us a hint,

As the psychologist Steven Pinker noted, “If you adopt children from a technologically undeveloped part of the world, they will fit in to modern society just fine.” That suggests, at least, that races don’t show big innate differences in behavior.

If that’s the case then let me provide such an anecdote. A few months ago I visited a library and was using one of its computers. A White woman walks by and for some reason drops her 6-7 year old daughter next to me and walks a way to do whatever she came for. Bad parenting, right?  Normally, I would have objected to this because I know what Swedish kids are like when unsupervised. But this was a child of clearly East Asian origin. So I relax and go on working on the computer knowing – or prejudicially assuming – that I most likely will not be disturbed by her. Sure enough, she remains quiet and stationary for over an hour until her mom picks her up.

Was I prejudiced in believing in this outcome? Are East Asian adoptive children every bit as loud and rowdy as Western children? It’s almost a rhetorical question. I suspect most people share my experience that there are indeed big innate differences between Whites and East Asians. Note that this doesn’t contradict what Pinker said. That girl fitted in just fine – but her behavior was still very different from ethnically Swedish children.

Creationists Are to PC Liberals as PC Liberals Are to HBD

So it seems like Coyne and his ilk are much more similar to creationists than they care to admit. Coyne views Pearcey’s fear of evolution and its social ramifications as “alarmist” but when it comes to divergent selection for behavioural traits in humans – when his own values are at stake – he becomes defensive and says it would be unethical to find out. And that, in my view, makes him a failed scientist.

But what about Coyne’s and Pearcey’s concerns? It’s possible that spree killers are inspired by Darwin as creationists fear, and it’s equally possible that racists are inspired by research on biological differences between human races as Coyne fears. I honestly don’t know. But should we ban scientific research on sensitive issues for this reason? And if so, do we abandon research exclusively on race or do we abandon the theory of evolution altogether?  Whatever your answer is, don’t do like Coyne: pretend like you’re a scientist and the bail on it when you get cold feet.

That said, this book is pretty good introduction to some of the basics concepts of evolution, and it certainly provides insights into how politics intermingles with science in the academic community. And it’s an easy read.

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3 Responses to Book Review: Why Evolution Is True (2009) by Jerry Coyne

  1. […] Book Review: Why Evolution Is True (2009) by Jerry Coyne – book review from staffan. […]

  2. Dense yet accessible, both rhetorically and polemically effective. Fantastic review–sharing it an introduction to HBD-thinking with lots of friends and family, thanks.

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