22 August 2010

evolution explained

When I was young, I told myself I was going to be a scientist. I wanted to do something exciting, like be a paleontologist or anthropologist, or even be involved in the field of genetics.

But at the tender and highly impressionable age of 8, I came across a show on TV that featured a frog being dissected. Just one terrified look at the quivering innards of a frog that was cut open, and all its limbs stuck with pins to keep the entire body in place--and thus ended what would have been a potentially exciting scientific career for Gina.

It was one of those traumatic experiences that made me refuse to dissect a frog back in high school--and I was willing to fail my science subject (although I doubt my parents would have wanted me to) just to avoid the whole frog dissection lab exercise, but the teacher took pity on me--seeing how miserable and traumatized I looked--and made me do a paper instead.

And so instead of being some really cool scientist, I chose to embark on a frog-free career in communications and fundraising. Whatever scientific aspirations I had left in me found an outlet in just reading up on landmark discoveries in books and the internet, as well as watching National Geographic and Discovery Channel (the remote control in hand, with me ready to do some rapid channel switching should an image of a frog come into view).

The first book I started reading this 2010 was Richard Dawkins' The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution. I could have finished it earlier this year, but there were too many distractions at work, and I even read a couple of books while I let The Ancestor's Tale sit on the bookshelf unfinished. It was only today that I started reading more chapters in earnest, these chapters covering the period of evolution 6 to 180 million years ago.

But back in January, I was already raving about the wonderful premise of The Ancestor's Tale in a previous post; I had just started then on the first few chapters of the book, which tackles first, in a radical reverse tour of evolution, the period of man's evolution that took place less than 6 million years ago, starting from that point where he "branches off" from his shared common ancestor with the chimpanzee.

My previous post pretty much summarizes what Dawkins' book is all about (and so does the Amazon link), so I won't repeat what I've talked about before. But I have to say that I do regret not finishing this book earlier; in less than 7 hours today, I have gone as far back as the Age of Dinosaurs, where one of man's earliest mammal ancestors during that period was the marsupial mole. (Yes, hard to believe, but hey, at least I'm still in the mammal kingdom. Give me a few more chapters, and I'd really start struggling with the idea that we are descended from lungfish.)

In a deeply religious country where most, if not all, believe that man came into existence as explained in The Bible's Book of Genesis, I choose to believe that in my own world, religion and science can conveniently get along with one another. I actually think that the First Story of Creation ties in quite nicely with the story of man's evolution--with the land and sea being created first, and then the plants and animals, and lastly, man, who is given dominion over all creatures.

Of course, everyone is free to believe in what they wish to believe in; I've never force-fed anyone my beliefs, and neither should anyone, not even my own mother (who gave up trying years ago to get me to attend church), coerce me into believing in God and denouncing science, and vice versa. The debate on religion versus science is moot, and there will always be a Great Divide, so I'd rather not waste energy arguing with people from these two opposing factions.

This does not mean I don't have a religious bone in my body; in fact, I believe in God so much, that I feel He is ultimately the Master at work behind the fearfully beautiful and intricate process of evolution. Nothing as grand as this--this whole scheme or design that takes place in the span of millions and millions of years, with each living thing being created and 'assigned' a function and purpose in life--can simply be left to chance alone. Evolution is complex, yet everything ends up falling neatly into place--and at least for me, I find assurance in the belief that only a higher being such as God can orchestrate something as wonderful as this.

That said, I just want to say how I am totally absorbed with the ideas postulated in this book. :)

Indulge me by letting me directly quote passages from the book; whenever a good thought or fact strikes me, I normally take note of it. Some ideas in books aren't exactly ground-breaking, as I've heard or read about them before, but I usually like how the author explains the ideas. I either write these down or manually type them, so that when I come back to these little notes, I remember which parts of the book I liked best. Dawkins is pretty adept in making science accessible and interesting even to the most casual reader--although of course, it helps to have a healthy interest in evolution for one to read this book.

On bipedality (walking on two legs)

"Perhaps we rose on our hind legs, not because that is a good way of getting about, but because of what we were then able to do with our hands--carry food, for instance.... Other kinds of food such as meat or large underground tubers are harder to acquire but, when you do find them, they are valuable--worth carrying home in greater quantity than you can eat. When a leopard makes a kill, the first thing it normally does is drag it up a tree and hang it over a branch, where it will be relatively safe from marauding scavengers and can be revisited for meals.... Having much smaller and weaker jaws than a leopard, did our ancestors benefit from the skill of walking on two legs because it freed their hands for carrying food--perhaps back to a mate or children, or to trade favours with other companions, or to keep in a larder for future needs?

A particular version of the 'carrying food home' theory is that of the American anthropologist Owen Lovejoy. He suggests that females would often have been hampered in their foraging by nursing infants, therefore unable to travel far and wide looking for food. The consequent poor nutrition and poor milk production would have delayed weaning. Suckling females are infertile. Any male who feeds a nursing female accelerates the weaning of her current child and brings her into receptiveness earlier. When this happens, she might make her receptiveness especially available to the male whose provisioning accelerated it. So, a male who can bring lots of food home might gain a direct reproductive advantage over a rival male who just eats where he finds. Hence the evolution of bipedalism to free the hands for carrying." (Dawkins, p. 91-92.)

Not only does the theory of man evolving from a creature walking on all fours to that of a bipedal entity interest me, but my recent attendance in a gender sensitivity workshop has made me more conscious of how man and woman have played out their roles in society (both in ancient and modern times) which directly result in how people today develop gender-based notions and decision-making.

On racism in evolutionary theory

"Early explorers often assigned the native peoples of the forests a closer affinity with chimpanzees, gorillas or orangs than with the explorers themselves. In the nineteenth century, after Darwin, evolutionists often regarded African peoples as intermediate between apes and Europeans, on the upward path to white supremacy. This is not only factually wrong. It violates a fundamental principle of evolution. Two cousins are always exactly equally related to any outgroup, because they are connected to that outgroup via a shared ancestor.... All humans are exactly equally close cousins to all gorillas. Racism and speciesism, and our perennial confusion over how inclusively we wish to cast our moral and ethical net, are brought into sharp and sometimes uncomfortable focus in the history of our attitudes to fellow humans, and our attitudes to apes -- our fellow apes." (Dawkins, p. 111.)

Powerful stuff. The Great Ape Project, as Dawkins also mentions, proposes that great apes should be granted, "as far as is practically possible" the same moral status as humans. This moving notion, like many other ideas in The Ancestor's Tale, sets my science-loving mind and heart racing.


Post a Comment