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Tuesday, August 18, 2009

Richard Dawkins' The Ancestor's Tale - audiobook review

The Little Foxes by sea turtle from flickr (CC-NC-ND)
I don't really read paper books much. Hours of staring at computer and reading blogs and other stuff online are enough effort for my laser-powered eyes. More often than not when I want to read a book, I get an audiobook version of it. Yes, audio has a lot of problems, like lack of searchability, and difficulty of just skimming through less interesting bits. And virtually all audiobook recordings are way too slow. Fortunately my wonderful MP3 player supports increasing audiobook speeds. Side effects include everyone sounding considerably higher-pitched than they really do, but that's something you can really get used to it. By the way - is there any way to avoid that? I know that the most naive algorithm of resampling the original audio wave changes pitch and speed at the same time, and that's what seems to be used, but there surely have to be some smarter ways, right? Especially since I wouldn't really mind even higher speeds.

So, today's audiobook review is Richard Dawkins's The Ancestor's Tale. The audiobook version is unfortunately abridged, what's the dumbest solution to low audiobook speed problem you can think of. MP3 player manufacturers should really do something about it. Or surely there must be some programs out there to speed up audiobooks without making it unreasonably high-pitched right? At least for The Pirate Bay's version, as opposed to DRMed versions.


Anyway, the book starts with extremely long and boring preface explaining what the book is going to be about. I'm pretty sure many people will just turn it off before the real material starts. Then there are 40 concestor steps - concestor being what's more commonly known as most recent common ancestor of some clade of organisms. Yes, if you want that explained, go ahead and listen to the book preface. Or read some Wikipedia.

Then we move back concestor after concestor, and tell a story of what happened to organisms that split from our branch at that time. The first stories are about Neolithic Revolution, and Behavioral Modernity - two major changes on the way from humans being more sophisticated chimpanzees to humans as we know them. I find the notion of sudden rise of Behavioral Modernity extremely dubious - it disagrees with any molecular evidence, and the only proposed mechanism - acquisition of language - is highly dubious. Our best evidence suggest Neanderthals could most likely speak just as well as us (their FOXP2 gene is identical to ours and anatomy of their speech organs seems to allow speech), what pushes language way back to our common ancestor with Neanderthals, at least 660 thousand years ago. If that was so, it would render all theories of language-behaviour connection completely ridiculous. If Neanderthals couldn't speak, our best estimate for acquisition of language is around 200 thousand years ago, about the time Homo sapiens arose.

In the audiobook Dawkins acknowledges the problem, but postulates that maybe around 50 thousand years ago (supposed time of Behavioral Modernity revolution) language became "more advanced" as opposed to old and primitive kinds of language - this radically disagrees with the data, as modern languages take just one generation of children to reach full complexity and richness, as attested by Nicaraguan Sign Languages and all world's creoles. Yes, I'm going to argue with Dawkins a lot, about things that's not directly related to biology.

In the early chapters Dawkins talks a lot about human culture. An amazingly cool idea is that sheep and alikes "domesticated" grasses. Here's how it supposedly happened - sheep graze on grasses and other plans, what's individual grass plants are not too happy about. But - grasses take grazing reasonably well, while most other plants are far more devastated. As the result sheep give grasses marginal advantage over other plants - sure you're hurt, but the competition is hurt more, and now you have more sunlight, soil, water etc. for yourself. Isn't that great?

Something similar might have happened with domestication, and there's a very interesting domestication story - about tame silver foxes. You know the list of domesticated animals, right? Wolves (aka dogs), boars (aka pigs), aurochs (aka cows) and so on. Foxes are very definitely not on the list - few carnivores are for that matter. So how hard would it be to take a random wild species like a fox, and domesticate it into a pet? It turns out just a couple of decades by selecting for tameness. No genetic engineering or advanced biotechnology necessary. You could run this experiment on your own, given enough money for food and keeping a few hundred animals of whatever kind you want. As a side effect, selection for tameness seems to select for a variety of different characteristics useful for domestication, such foxes behave a lot more like dogs than like wild foxes. It will obviously take longer with species that breed slower than foxes, like most primates. That was your first thought, wasn't it? Domesticated marmosets!

Actually am I reviewing the audiobook or just randomly talking about various subjects vaguely related to it? Oh well, that's my blog, so you know what to expect, and staying on topic it is not! So I want to say I think Jared Diamond's argument that Europeans "had to" win the race because of geographical opportunities makes a lot less sense if you look at the data. The argument goes something like this - there are only 14 species of large domesticated animals. Therefore, there are only 14 species of large domesticable animals, and every animals that wasn't domesticated was obviously impossible to. This is bullshit, as silver foxes prove - just a couple of decades of effort, and you add another animal to the list. OK, it's not a "large" animal, so it doesn't count according to Diamond's criteria, but it proves that domesticated and easily domesticable are nowhere near the same thing.

Oh, and it's not like there weren't any other large animals elsewhere in the world. The Earth was full of them. Not only large land masses like Afroeurasia (silly name, but it makes sense here, as animals can walk from one end of it to another easily, climate issues notwithstanding), but also in Americas, and even on many small islands like Madagascar (elephant bird) and New Zealand (moa). The ones in Eurasia and Africa were just best at not getting extinct, probably by being exposed to Homo for millions of years, as opposed to suddenly.

Dawkins talks about it a lot, not just in the first chapters but all through the books. One amusing idea of his is the "wild Homo sapiens". What does it even mean? We're certainly not wild since the Neolithic Revolution, and arguable we never were. A simple question - do humans form a single species? That's an absurd question, of course they do, after all they can and do interbreed.

But isn't the criterion interbreeding in the wild? Do you know any wild Homo sapiens? Even modern hunter-gatherers are most emphatically not wild, with all the "contamination by civilization", and it's difficult position to claim that Paleolithic humans were really wild. Dawkins gives an example of a pair of grasshopper species that can interbreed perfectly well in zoos, but in the wild they never do so because they use incompatible mating songs. And according to him - how is it different from different groups of humans not interbreeding due to incompatible language and religion? Yes! Dawkins pretty much blames religion for development of human races.

Did I mention how the book doesn't bother with disclaimers, or political correctness, and whenever Dawkins disagrees with someone, he pretty much calls them names - with traditional British eloquence rather than common blogger vulgarity like I do, but it's pretty much the same thing. Oh by the way if you want some solid evidence that religion is a good barrier to human interbreeding, apparently European Ashkenazi Jews rate of interbreeding with surrounding European population, without any geographical or linguistic barriers, purely religious ones, was barely 0.5% per generation - a Jewish person was 200 more likely to mate with another Jew than with a non-Jew. It can be realistically imagined that with addition of some linguistic and geographic isolation barriers between tribes might have been much more significant, leading to a situation where an impartial observer might call different human tribes "distinct species". Of course this situation isn't permanent, and for example intermarriage rate for modern American Jews is 47%, far higher than historical rate even just a couple of decades ago. This makes such barriers temporary at worst, not enough to cause speciation, but plausible partial explanation of the origin of races.

Yes, Dawkins does talk about races. One of his claim about reality of races is how much different observers agree who belongs to which race. Like Colin Powell, who is supposedly "black". By the way, he doesn't look the slightest bit "black" to me - he's a total whitey to me, and Obama is obviously mixed race, not "black". But what do I know, I'm not American. By the way at various stages of history English-speaking people used to believe Irish, or Jews, or Southern Europeans, or Central/Eastern Europeans, or Middle Easterners, or Hispanics, or Indians etc., were "distinct races", even though they're all obviously totally white to me. Oh wait, they still believe Middle Easterners and Hispanics are "distinct races". Silly Americans. There's even plenty of Japanese people who look quite white-ish to me, even though most don't. So I don't really buy the "interobserver agreement" argument.

Dawkins talks a lot about how we shouldn't be giving to much weight to labels like species, and higher clades like phyla. There's plenty of cases like ring species, and gradual divergence of distinct clades where such thinking leads to unnecessary confusion.

Before humans

Wow, I wrote so much and I didn't even get to concestor 1 - of us, Common Chimpanzee, and Bonobo. Numeration starts from concestor 0 - ancestor of all humans. I'm not following the audiobook chapter by chapter - Dawkins talks about human issues a lot, all throughout the book. So first, I don't really buy the idea that there's some relevance of "a common ancestors of all living humans", supposedly living just a few thousand years ago, by statistical argument. Because humans reproduce sexually, we have a gene pool, and it doesn't really matter if there was such an individual or not. Imagine there's an island with 1 man and 10 women. That guy will be the common ancestor of everyone on the island starting from the next generation, but that very much does not mean all the genetic divergence only starts then. Perhaps the women are from 10 different places is the world, isolated for tens of thousands of years - genetic divergence would go hundreds of thousands years back. This is an exaggerated example, but with sufficient mixing of gene pool the time of one of the most recent common ancestors can easily be orders of magnitude than the time of the last genetic divergence.

This is less of a problem for earlier concestors. But there's a second problem. Dawkins claims there are only 40 concestors on our road from humans to concestor of all currently living organism. But that's just limits of our knowledge. It's quite likely that a few more concestors will be inserted around our merger with other Eukaryota, and then with Archaea and Bacteria. Or perhaps not. There are fairly strong limits on our knowledge of evolution that far back.

I think Dawkins commits something I'm going to call the "cladistic fallacy" - the idea that for example humans cannot possible be more closely related to Bonobo than to Common Chimpanzee, just because Bonobo and Common Chimpanzee have a common ancestor not shared by humans. This is technically defensible position, and well calibrated molecular clocks will confirm it - but how many years in the past we shared an ancestor is not a meaningful measure of relatedness!

For one, the same number of years doesn't mean the same number of generations - otherwise you would be equally related to your brother and your nephew, just because your last common ancestor in both cases is the same - that's obviously nonsense. More importantly, different evolutionary lines can diverge at different rates.

One example is Canine transmissible venereal tumor, a single-celled parasite of canines that evolved from dog tumor tissue hundreds or thousand years ago. Yes, it's a different species by all means. But it would be ridiculous to say dogs are more closely related to CTVT than to let's say coyotes. Sure, genetic clock says so, but that's not a meaningful measure of relatedness. CTVT is not a canine mammal is any meaningful sense of the word. Another such parasite is DFTD. There's also an arguable case of HeLa (Helacyton gartleri) - a similar species derived from humans - but in this case we could ignore it as a artificially created. A less drastic example are hippos and whales - yes, technically hippos are "more closely related" (as measured by time) to whales (Cetacea) than to any other Artiodactyla, but is it really the best measure? By the way, it's not really mentioned in the book, but there's an interesting even though most likely false theory that humans are more closely related to orangutans than to Chimpanzees, using similar arguments. Read if you're curious, even if it's unlikely.

Dawkins also panics for a moment about the problem of comparing all species against all others. Hippos and pigs both look like perfectly good Artiodactyla, so if you naively assume that it's a proper clade and try to just take one of these species for genetic comparisons, you might get different family trees. I understand his point, but DNA sequencing is getting ridiculously cheaper at exponential rate (I mean, genuinely not just metaphorically exponential). When the book was released apparently humans and mice were the only two mammals with fully sequenced genomes. Not any more. Right now there are at least 10 fully sequenced mammalian species. And you don't even need full sequences for genetic tree reconstruction, just a selection of a small number of representative genes will give a pretty decent approximation. It's funny how quickly books about biology get outdated.

Most of the audiobook is about different animal groups, and interesting things about them. Like how Deuterostomia (that's you) can be thought of as upside-down Protostomia (like insects). And how to explain Cambrian explosion - is it just an artifact, or was it real? How to explain the paradox of sex - why do you throw away half of your genes when you make children, instead of just cloning yourself and doubling your genetic success? How truly irreducible complexity (which we haven't found at all, so don't worry) would be a good evidence of directed panspermia, as opposed to creationism. About endosymbiosis, fish lungs, Platypus's bill, some theories on origins of life, and a lot more. Half of the stories are excluded from the abridged audiobook, unfortunately, so go on get a paper version if you want to get them all.

That's more or less what the book talks about. It's not the best Dawkins ever (especially the overly long preface annoyed me), but it's pretty decent Dawkins. Highly opinionated (and I don't always agree with his opinions), eloquent, and about something extremely interesting. It's definitely popular science, so hardly any biological background is needed. Enjoy.


Anonymous said...

Quite possibly the most critical positive review ever :)

I'm just about finished reading the paper version (have been working my way through it for a month or so with some others). A surprisingly interesting read considering the detail he goes into at times (I really have no biological background at all). At the same time not too surprising as Dawkins' is nothing if not someone great at putting down some prose.

Definitely a fair review as it's clear that Dawkins is speculating at times (but he's good to try to spell out when he is speculating past the accepted theories). I felt that in general he's doing a sort of survey of current theories rather than necessarily trying to make up his own.

Good stuff.

Michael J.T. O'Kelly said...

If you want to change the tempo, but not the pitch, you can't do much better than SoundTouch (which is FOSS):

Some complicated maths being done there under the hood. :)

Anonymous said...

The easiest way to modify speed on Mac is with QuickTime Player:

On Linux apart from SoundTouch which Michael mentioned, this plugin might be useful: