Science & Nature Archive

Monday, February 12, 2007

Review of Darwin's Origin of Species

There is a follow-up to this review, written after I finished reading the book. However, both of thses entries have been supplanted by a newer post, which combines the two, with a little editing, and a paragraph's worth of new content.

Cover of Origin of SpeciesSince today is Darwin Day, I figured I ought to post something. As it turns out, I'm currently reading The Origin of Species. I'm not quite done with it, yet - only about 2/3 of the way through - but I wasn't intending to write an in-depth review, anyway; I was only going to cover my general impressions of the book. So, with today being the day it is, I figured this would be a good time to do it, as I doubt my opinion will be changed much with the last third of the book.

Long before I picked up the book, I already had a pretty good understanding of evolution - better than most laymen, I'd wager. So I didn't start reading Origin of Species to try to learn anything about the theory. Rather, it was more to do with my interest in history, particularly for this case my interest in the history of science and technology, that was the reason I wanted to read this. And it doesn't disappoint.

Okay, let's get the background out of the way, first. Origin of Species was published in 1859, with the full title, On the Origin of Species By Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life. It's not that Darwin was the first to propose some type of evolution and common descent, but Origin of Species really was the book that presented the evidence in such a way, and proposed a plausible mechanism, that the theory really came to be accepted.

Part of what I find just so fascinating is how Darwin came up with all this without any knowledge of genetics. Even though Gregor Mendel was performing his pea plant experiments around the same time that Darwin wrote Origin of Species, it appears that Darwin wasn't really aware of Mendel's work. In fact, it wasn't until the early 1900's that the scientific community recognized the importance of Mendel's experiments. And it wasn't until the 1940's and 50's that people finally understood what DNA was and how it controlled heredity. Obviously, people in the 1800's knew that offspring bore some resemblance to their parents, but nobody knew how exactly this happened, or what it was that caused offspring to have variations. So Darwin was kind of left groping around in the dark, and all throughout the book, he's reduced to explaining concepts while admitting that he doesn't truly understand the mechanisms responible. From a modern viewpoint, understanding genetics, it almost makes you wish you could travel back and explain it to Darwin. It would have made things so much easier for him.

So knowing that Darwin was ignorant of genetics, and knowing that our knowledge of the geologic record was even less complete then than it is now, it's interesting to see the insights Darwin had that lead him to formulate the theory. For me, when I think of evolution, I think of fossils. Yeah, I know there are multiple other lines of evidence, but growing up, that was the main line of evidence that convinced me that evolution actually happened. But Darwin only briefly discusses fossils in two chapters of the book. The rest of Origin of Species is about what he observed in the world around him - how there seem to be clusters of similar species, the difficulties of distinguishing between true species and merely varieties of the same species, the geographical distribution of species, etc.

It's also interesting how Darwin determined that variation and natural selection were the mechanisms responsible for evolution. Consider one of Darwin's contemporaries, Jean-Baptiste Lamarck. Lamarck came up with the idea of "Use and Disuse," that animals could affect their own bodies through their actions, and that they could then pass on these acquired traits to their offspring. The classic example of this is a giraffe stretching its neck to reach higher leaves, and it's offspring thus having a longer neck because of it. Thanks to genetics, we now know this is a false view. To be fair, Darwin didn't rule this out entirely in Origin of Species, but he concluded that it must have been secondary to variation and natural selection. And one of the best examples he used to demonstrate this was ants - all the variation evident in workers, even though it's the queen that lays eggs.

I also find it fascinating to read Darwin comparing evolution to special creation, to think that creationism was the dominant scientific theory of the time. What I find especially fascinating, is to think how people integrated this into the knowledge of an ancient earth. Darwin fequently cited Charles Lyell in Orign of Species (Charles Lyell was one of the early popularisers of uniformitarianism, and helped promote the idea of the Earth being truly ancient), and in his chapters on the geological record, Darwin discussed some of the different geological periods. And concerning fossils appearing in the geological record, Darwin tells of how people proposed that those species were created during those periods. Just imagine that - seeing all the evidence for an ancient earth, and thinking that different species had been specially created throughout the history of the earth. I suppose without a better explanation, that's all the people could come up with then, but it certainly does seem an odd idea now.

I've read other places that evolution, through Origin of Species, was one of the last major scientific theories that was first presented to the world in a book intended for a lay audience. It wasn't presented in a peer reviewed journal; it wasn't full of technical jargon or equations; it was a book published by a regular publisher and sold through normal venues. It was easy to understand, and became a best seller. Now we need science writers to translate for us lay people, so we're always a few steps removed from the real science. It's hard to imagine any new major theories being presented the same way evolution was in Origin of Species.

I'd recommend this book to anyone with a good understanding of evolution who's interested in the history of the theory, but not necessarily to those people who don't undertand evolution, yet. For one thing, Darwin gets a few things wrong. For another, being written in a style 150 years old, it's not the easiest thing for a modern reader to understand. And finally, genetics is such a huge component of evolution, that a good introduction to evolution should include genetics in its explanation.

Anyway, despite any mistakes he may have made, Darwin certainly made a huge contribution to our understanding of the world. Happy Darwin Day, everybody.

Tuesday, February 6, 2007

Upcoming Darwing Day Event in Wichita Falls

Darwin Day GraphicWhile reading the latest entry on The Loom, I found out that there's actually a holiday called Darwin Day. Following the link that Zimmer provided, I found that there's even an event going on right here in my own hometown of Wichita Falls. Whoda thunk it? I doubt I'll go, but it's nice to see things like that here in this part of Texas.

(Yeah, I stole that picture from Zimmer, but I figured that a caricature from the 1800's was probably in the public domain by now.)

Thursday, August 24, 2006

Knowledge for Knowledge's Sake

This is something I wrote the other day in the comments of a TerrapinTables thread. It's short, but I like it enough that I wanted to post it here on my own blog. It was in response to the following question posed in relation to studying dark matter (prompted by this article), "But tell me this: first, I mean, seriously, aside from knowledge for knowldege's sake, why do we need to know what comprises a galaxy cluster infinity-miles away?" Here is my reply:

First off - I think knowledge for knowledge's sake is a good enough reason to do research. In the same way that some people may find beauty in a painting, others can find beauty in a deeper understanding of the mysteries of our universe. If you're going to question why we need to know about a substance that composes 1/4 of the universe, I could just as easily ask why we have an entire profession dedicated to smearing paint on canvas, or another profession dedicated to plucking guitar strings and beating on drums. (Don't take me the wrong way - I'm not saying the arts aren't worthwhile; I'm saying that I think pure knowledge with no practical applications is just as important.)

But aside from that, who knows where knowledge will lead? Like in the 19th century, when physicists were trying to measure the ether that light travels in, could they have known that it would eventually lead to such practical applications as lasers, CDs and DVDs? Or the geologists of that era, did they really start off thinking that their theories would lead to the abandonment of a literal interpretation of the bible (at least in most of the developed world, not counting the U.S.)?

So there you go - one example of knowledge that led to practical technical applications, and another that had huge societal & cultural implications. I'm sure I could go on listing more, but you get the point.

Friday, July 14, 2006

Physical Comparison of Humans to Other Animals

Not too long ago, I made a blog entry, Request for Information - Physical Comparison of Humans to Animals I actually did receive some feedback in the form of e-mail, which inspired me to do more research. In the course of which, I found the paper, Differential scaling of locomotor performance in small and large terrestrial mammals, written by Jose (Pepe) Iriarte-Diaz, which was published in the JOURNAL OF EXPERIMENTAL BIOLOGY, 205 (18): 2897-2908 SEP 2002. Anyway, as part of his research into animal locomotion, he had compiled a large set of data of mammal max running speeds along with their body mass and length. This was exactly the type of thing I was looking for in order to characterize how humans compare to other animals.

Continue reading "Physical Comparison of Humans to Other Animals" »

Wednesday, May 31, 2006

Request for Information- Physical Comparison of Humans to Animals

I'm throwing out a request for information for how humans fare physically in the animal kingdom. If anyone can supply me with links or recommend books on this topic, please do so in the comments. (I don't know how many people will even read this entry, but throwing it out there doesn't hurt.)

Here's where I'm coming from on this. I grew up as a kid who loved watching PBS, and then the Discovery Channel once we got cable. The types of animals that get all the attention are the fastest, the biggest, the strongest, etc.. And these animals are always compared to people, to try to put their skills into perspective. Growing up, I got the impression that humans were pathetic physically, and it was mainly our cleverness that allowed us to be so successful (along with our bipedalism and opposable thumbs). Now, my daughter watches The Most Extreme on Animal Planet, which seems to emphasize this even more.

Recently, there was an article in the 18 November 2004 issue of Nature, titled "Endurance running and the evolution of Homo." There is a very good summary and discussion of this article at the old Pharyngula site. Whether or not endurance running was a major driver of human evolution, I find it very interesting that humans are so good at long distance running, especially after all those years of documentaries telling me how pathetic of runners we are.

Hence, the request for information. Are there any places out there with comparisons similar to the above article, that show how humans fare in the animal kingdom, and not just compared to the biggest/fastest/strongest? If not, where would I go about finding this type of information, so that I could start making my own comparisons.

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