Pages

11.24.2012

Evidence of Evolution - Darwin's Theory of Evolution


There is little hope of convincing Creationists that Darwin's Theory of Evolution is right and they are totally wrong. So let's forget about them for a minute.

There are surely a lot of people out there who are not fundamentally religious and just want to understand Darwin's Theory and the mountains of evidence for evolution that exist. Not everyone is a scientist, but many people are curious about science and seek truth.

As with global climate change, it is hard to get correct and rational information when there is so much misinformation flying around from people who are willfully ignorant, or more diabolically want to deceive (mostly hardcore church people have a vested interest in deception against evolution, because their livelihood depends on people rejecting Darwin's theory and the evolution timeline of billions of years, in favor of the patently false Biblical creation story and it's absurdly short timeline).

The best and brightest book for lay people about evolution by natural selection is Richard Dawkins' "The Greatest Show On Earth."

In it, Dawkins explains it all in very easy to understand words, and he destroys all religious rebukes and rebuttals easily (it's not hard to disprove falsehoods). It's by far the best and clearest overview of evolution by natural selection in general. If you are an evolution skeptic before reading this book, you will have no doubt that the theory of evolution is real and correct afterwards. So if you are a fundamentalist religious person and want to keep your head firmly in the sand, DO NOT read this book. Conversely, if you are secure in your faith, you have nothing to fear from reading this book and might learn something (CAUTION: It's the Devil's work, ha ha ha!). Everyone else can read it knowing they will be well informed and even entertained.


If you want to learn about the timeline of evolution on earth, I must once again refer you to Dawkins. His book, "The Ancestor's Tale," illustrates the evolution timeline beautifully, by working backwards from the humans of the present to the first lifeforms on earth.

Interestingly, on the tree of life, there are only about 40 branch points between us and the first microbes. This is actually mathematically verifiable, although it seems counterintuitive. You can take any two life forms on earth today and if you go back far enough, they will share a common ancestor. Consider that our most recent branch point is shared with chimpanzees, considerably different from us. Nothing has branched off from the human line since the ancestor of chimps did, although chimps subsequently split into several species. But we don't count the chimp branch points on our line because our ancestors had already split off by then.

One thing that even non-religious people don't get is that humans did not evolve from chimps. Both chimps and humans evolved from a common ancestor who was partly chimp-like and partly human-like (we'd probably say it was more chimp-like, and chimps would probably say it was more human-like). As soon as the two species split off, the ancestral species ceased to exist. One group gradually evolved over time into chimps and the other gradually evolved over time into humans. The ancestral species lived on the earth up until the time of the branching of the two species, but it does not exist today, except in the fossil record.


Dawkins also has a book called "The Blind Watchmaker," about the biological mechanics of evolution. Here he explains how animals evolve through incremental changes over long periods of time and how complex organs like eyes can develop. Critics of evolution argue that something as complex as an eye could not evolve incrementally because there is no such thing as a partially formed eye in nature.

"Hogwash!" says Dawkins (he probably doesn't say that really). Nature is full of examples of partially formed eyes, from simple light sensitive cells in worms, to compound eyes in insects, to pinhole camera style eyes in other organisms. In fact, the human eye, he points out, is designed horribly (unintelligent design, from an engineering standpoint), back to front, but still performs amply well for our needs. The squid has an even better eye than we do.

Another mistake the anti-evolutionists make is to suggest that evolution can't be true because otherwise there would be intermediate species in the fossil record. They say this as if they are fully confident there are no intermediate species in the fossil record. The only problem is that the fossil record is rich with intermediate species, especially younger fossils like the putative common ancestors of humans and chimps. Dawkins exposes this Creationist fallacy in "The Greatest Show On Earth" as well.


For the more advanced students of the science of evolution, have a look at "The Extended Phenotype," by Dawkins. This is a more technical text, akin to a college level textbook, which Dawkins disclaims right away in the foreward, so no one can call him out on that. This book is not the best choice for a first encounter with Dawkins' writing, unless you are technically savvy and well versed in the biological jargon of genetics and evolution by natural selection. Even then it can be a decent sedative. Definitely read one of the books above, or perhaps his seminal work, "The Selfish Gene (even my scientifically timid mom enjoyed that one)," if you want to ease into the writing of Dawkins. "The Extended Phenotype" is more of a plunge into deep, exotic waters.

Comments or questions are welcomed.

No comments:

Post a Comment