A Pilgrimage to the Dawn of Evolution by Richard Dawkins
with Yan Wong
I don't think anything I write can do this book justice. It's staggering in scope, dense with details, mind-expanding and yet surprisingly readable. The premise bases a look at evolution loosely on
The Canterbury Tales- the idea being that we time-travel skipping backwards to points where can meet up with common ancestors (the first is shared with chimpanzees) then on down through the ages meeting up with common ancestors of other primates, smaller mammals, fishes, etc etc on down to the one-celled organisms that arose at the dawn of time (and so many of them are still here on earth with us). Calling each chapter something like "The Peacock's Tale" or "The Rotifer's Tale" was a bit of a stretch- these weren't narrative tellings of anything, but very brief descriptions of the varied life forms and then lessons on what they can teach us about how we are all related. About gene transfer and how enzymes build proteins, about divergence and likewise convergence of species, about drifting and inheritance and molecular biology and tons more. I admit I did not understand it all, there were plenty of sections I had to read twice, but I didn't skip anything. Some of the stuff about molecular clocks and the math and chemistry when you get the end chapters about one-celled organisms that existed before plants converted solar energy into what others could consume- well it felt over my head. But there was so much that made me go
wow, or sit and think hard, or feel just boggled by the huge swarms of life that we can't even see- like
this diagram that shows how all life is related via molecular comparisons? it's got about eight branching groups each with five to eight branches in there- the others are all things like algae, slime moulds, amoebas, fungi and things I don't even know- radiolarians and pelobionts and so on. Plants are one tiny branch.
Animals are another- and we are such a tiny fragment of that it's not even visible on the diagram! It is mind-numbing the way that
Watchers at the Pond is. One main idea stated here was that we are more closely related- at the molecular level- to some bacteria, than those bacteria are to
other bacteria. That's how huge and varied the expanse of life really is.
Some things of wonder in this book: this "
brain map" that shows parts of the body in size difference according to how much of the brain is devoted to sensory input from and control of them. On the star-nosed mole biggest are the nose tentacles and then the digging paws. On humans, it's the
hands, and only slightly less the facial features especially the mouth (for speaking). Ever wonder why a tiny injury on your hand can hurt so much? well they're so dang sensitive and your brain has so much invested in their control and dexterity. So many things I looked up more about: the bdelloid rotifers which have been reproducing asexually- apparently there are no males- for
40 million years. The trichoplax, a tiny organism only a few cells thick that reveals a lot about early life, and I never knew it existed. The tooth-billed pigeon otherwise known as the little dodo- because it's the only living relative of the dodo and is on the verge of disappearing now, too. The microorganisms that live in termite guts- without them, the termites could not digest cellulose. To those microbes, the termite is the whole world. Who is serving whom in that regard. I thought of all the little things living in my own gut. I thought much more closely about viruses and bacteria near the end of this book.
It was hard to wade through some of the later chapters about the tiny microscopic life forms, simply because all the terminology about them is unfamiliar to me. But I was wowed by the next-to-the-last chapter. I really liked the explanation comparing the spread of fire, to how reproduction can happen without heredity and why that's significant. Also the description of what the atmosphere and basic components on earth were like before oxygen really existed. There were other things that, when a scientist put them all in a vat and left it sitting for a few weeks, turned into a "soup" of biological compounds- which with the right catalyst could spring into life. My husband tells me he's read of an experiment where basic elements were put together and a living cell was made, unlike any other living cell that's existed before. I had no idea. Look up synthetic biology.
And here's another big picture idea- Dawkins tells how many times evolution has come up with specific things- eyes for example, or the power of flight. Very few things have happened only once (there's one bacteria that created a wheel!) So he posits that if most of life were wiped out, it would eventually all arise again- because the basic pieces would still be here- and just like the dinosaurs had all kinds of animals that filled all the niches- some that ate plants others that ate the grazers, some that climbed or flew or ate insects or used sonar in the ocean- the mammals spread to fill them after the dinosaurs were gone. On isolated islands like Madagascar or the continent of Australia, a slightly different form evolved to fill all the niches (think the marsupials). If an asteroid nearly wiped out all life, it would rise again and proliferate into all the diverse forms- maybe not with humans in it, but eventually with something pretty darn close. It's a lot to think about. I will say, I don't feel as much dread of us ending everything with our destructive ways- LIFE will recover again, we just wouldn't be here to see it! ha. And I'm also not quite so leery about GMO's either, if the commonality of genes between all living things like Dawkins outlines in here, is what I understood from it. We are all interrelated, much closer than you'd imagine.
No way is this even a fraction of what I gleaned from this book. I borrowed a copy to read from my brother in-law, but I'd sure like to have this in my own library someday. Maybe the newer edition, which I gather has a few updated chapters.
Rating: 4/5 671 pages, 2004
