Science & Nature Archive

Friday, March 7, 2008

Book Review - At the Water's Edge

The full title of this book is At the Water's Edge : Fish with Fingers, Whales with Legs, and How Life Came Ashore but Then Went Back to Sea. It was written by Carl Zimmer, and as the long title suggests, is all about those two dramatic transitions of life evolving into such distinct environments. This book was great - one of the best non-fiction books I've read in a while. It was just the right blend of story telling, concepts, and evidence, and made for a very compelling read. In fact, I think I finished it in less than a week.

When I reviewed another book by Zimmer, the Smithsonian Intimate Guide to Human Origins, I commented that it wasn't very in depth. At only 176 pages, much of them filled with photos and illustrations, it was a little light on commentary. At the Water's Edge is very different in this regard. It's 304 pages, filled with small print, with only enough diagrams as are needed to illustrate a few key points. It's not a tome, by any means, but it certainly provides Zimmer with enough space to do this subject justice.

The book is divided into basically two halves - the first dealing with the transition from lobe finned fish to early tetrapods, and the second half dealing with the transition from mesonychids to dolphins and whales. As would be expected, both halves deal with the specifics of each of those cases - transitional forms that have been discovered, environmental pressures that would drive the transition, etc. However, mixed throughout the entire book are also sections on general theory. There's a nice section on development in the beginning, covering such topics as Hox genes and non-genetic factors; he describes exaptation; there's another section on cladistics; as well as sections on many other concepts related to evolution.

I learned quite a bit by reading this book. Even though I was already familiar with much of the general theory, Zimmer presented it in ways that made me think of things differently. He also introduced a few concepts, such as the evolutionary "quit point," that I hadn't thought of much before. Still, where I learned the most was in those specifics of the transitional forms between fish and tetrapods, and land mammals and whales.

I'll give one example of something very interesting I learned from this book. (In fact, this was the very first passage of the book that I read, when I first got it and was just thumbing through to see what it was like.) At some point, our ancestors must have developed lungs to breathe air, obviously. When we look at the world around us, most fish today cannot breathe atmospheric air - they rely on their gills to get oxygen from water, but also have organs similar to lungs called swim bladders, which they use to regulate their buoyancy. From that observation, you may be tempted to think that lungs are a modified swim bladder, which perhaps evolved to allow fish to survive in swamps or other oxygen poor environments. After all, what need would an ocean going fish have of lungs? I know that's what I had thought, but as it turns out, it's almost certainly wrong.

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Friday, February 22, 2008

Book Review - Smithsonian Intimate Guide to Human Origins

I already posted a brief review of this book in my review of the Lucy's Legacy Exhibit at the Houston Museum of Natural Science. I don't really have much to add, but I thought I ought to at least give that review some closure, since I'd only read 2/3 of the book when I wrote it. I also figured this would give me a good chance to get the review into my Books section.

The book is the Smithsonian Intimate Guide to Human Origins, by Carl Zimmer. I liked it. It's not very in depth - it only took me about one weekend to read the whole thing - so if you follow science news, you probably won't learn a whole lot from it. That's not to say you won't learn anything - I certainly did learn a few things from this book, but most of the information was a review of what I alread knew.

But, it does have lots of pretty pictures that make it worth the price. And I mean that in the best possible way - paragraphs are all well and good, and it would be impossible to teach evolution with nothing but glossy pictures, but it can be nice to have a page full of pictures of fossil skulls, to see with your own eyes the similarities and differences. Sometimes pictures do show things more clearly than words ever could. Plus, if you don't follow science news as much as I do, or happen to know a person who doesn't know much about human evolution, it makes for a very good overview. If someone doesn't want to read the whole thing, but they're willing to listen to you explain something to them, you can still use the book, and open it up to some of those pretty pictures to help illustrate your point.

Tuesday, February 12, 2008

Book Review - Voyage of the Beagle

In honor of Darwin Day, I figured I'd post a review of The Voyage of the Beagle, which I just recently finished reading. The edition I read was actually the one from The Folio Society, given to me as a gift, and not the one pictured at right from Amazon. The book is also available as a free download from Project Gutenberg as a text only version, or as html with pictures, or from The Complete Works of Charles Darwin Online.

There are many reasons to like this book. One can't ignore the historical importance, since this expedition gave Darwin much of the insight that would lead to developing the theory of evolution, but this book would still be interesting even if Darwin had gone on to do nothing after sailing on the Beagle. The book is basically the journal of a young man on a round the world voyage, visiting much of South America, Tahiti, Australia, and a few other places, describing all the different cultures, geographies, and animals that he encountered.

For this review, I'll quote heavily from The Voyage of the Beagle, letting Darwin speak for himself, to give the reader a better idea of the language of the book. But first, let's get the somewhat confusing background out of the way. Darwin went along on the second survey expedition of the HMS Beagle. The first expedition, begun in 1826, consisted of two ships, the larger HMS Adventure, captained by Phillip Parker King, and the smaller HMS Beagle, captained by Pringle Stokes. Stokes committed suicide near the end of the first expedition, and 23 year old Flag Lieutenant Robert FitzRoy was named as temporary captain of the Beagle. On the second expedition, begun in 1831, only the Beagle returned, and as FitzRoy had proven himself well enough as temporary captain on the first expedition, he was given command of the ship for this second expedition. Worried about becoming depressed and suffering the same fate as Stokes, FitzRoy invited Darwin along for the journey so that he could have someone to talk to. As survey expeditions, the main purpose was acquiring data to produce nautical charts. Darwin had a slightly different agenda, as a naturalist, collecting many samples of the flora & fauna and taking many notes along the way. After the expeditions' completion, a four volume account was published, titled, Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle. The third volume of this narrative was written by Darwin, and titled, Journal and Remarks, 1832--1835. Darwin's volume proved to be so popular that the publisher, Henry Colburn of London, decided to publish it as a stand alone book, renamed, Journal of Researches into the Geology and Natural History of the various countries visited by H.M.S. Beagle. The book was published several more times under several different titles, but is most commonly referred to today as The Voyage of the Beagle.

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Thursday, October 18, 2007

Book Review - Origin of Species

Well, I just announced that I was starting a new Books section, so I figure I ought to post a book review. But, I'm going to cheat a little on this first one - I'm going to combine two previous posts, with a little bit of editing, and adding only a paragraph's worth of new content.

The book is the classic, Darwin's The Origin of Species. 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 my interest in the history of science and technology. And it doesn't disappoint.

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Monday, October 1, 2007

Review of the Lucy's Legacy Exhibit at the Houston Museum of Natural Science

This exhibit is now at the Pacific Science Center in Seattle, Washington. I haven't seen the exhibit there, but I'm guessing that it's pretty similar to what was in Houston. If anybody who's seen Lucy in Seattle happens to come across this review, please leave a note in the comments section to let me know if they've changed the exhibit at all.

Lucy's fossilsThis past weekend, my family and I went down to the Houston Museum of Natural Science to see the Lucy's Legacy exhibit. For anyone unfamiliar with this topic, Lucy is the nickname given to an Australopithecus afarensis fossil found in 1974 in Ethiopia (her nickname in Amharic is dinqineĊĦ, "you are wonderful"). At the time, she was one of the oldest, most complete hominid fossils found, and helped clarify a long standing question in human evolution of which came first - big brains or bipedalism. (Thanks to Lucy, and confirmed by other fossils, we now know it's bipedalism.) She is still one of the most complete early hominid fossils, and still very important to science (more info - article on Slate).

I'm going to do this review a little backwards. Lucy was the very last part of the exhibit, but since she was the main reason we drove 6 hours to go to Houston, she's what I'm going to discuss first. If you study human evolution at all, there's really not much to be said. You already know what the bones look like. Seeing them in person doesn't teach you much, but there's just something magical about it. I stood and stared at her for as long as my family would let me, and had butterflies in my stomach the whole time. To look down at that little 3'-8" skeleton, knowing how long ago she lived and how closely related we are to her - no words can do justice to the feeling you get.

Lucy's skeleton was in a case in the middle of the room, with all the bones laid out flat. There's was thick glass or plexiglass protecting the bones (or some other material - I didn't want to touch it and put my fingerprints on it). A few feet away on one side, cast replicas of the fossils were arranged in an upright position, in the way they would have been in life (similar to the picture of Lucy on Wikipedia). A few feet away on the other side is a fleshed out, full size reconstruction of what Lucy might have looked like (this article on Bloomberg has a photo of the head of the reconstruction). It was nice to see those three things together to put the bones into perspective. On the circular outside wall of the room was a 78 foot long, 10 foot high mural by Viktor Deak, artistically representing 6 million years of hominid evolution (if you subscribe to Natural History, the cover of the October 2007 issue shows a portion of that mural, and for the time being, their website does as well). I think the mural was my wife and daughter's favorite part of the exhibit.

I have to bring up one negative point about the exhibit. Just before you go into the room with Lucy, they show a short film about how she was found and the fossils' significance. And it was during this film that something jumped out at me as being wrong. I forget the exact wording, but the film said something to the effect that some scientists believe Australopithecus might have split into two groups - one giving rise to chimps and the other to humans. However, my understanding is that the chimp/bonobo and human split was around 6 million years ago (more info), and that australopithecines are on the hominid side of that split. And with Lucy being a member of the species A. afarensis, and living around 3.2 million years ago, she almost certainly was not an ancestor of chimps or bonobos, as that film seemed to imply (or at least what a laymen ignorant of human evolution might have taken away from the film, giving the film makers the benefit of the doubt and assuming they were referring to an earlier species of Australopithecus).

As far as I could tell, Lucy was the only actual fossil in the exhibit. Maybe I missed them, but all the other "fossils" I saw were cast replicas. They were still interesting, and still helped tell the story of hominid evolution, but didn't inspire the same awe you get looking at the real thing. There were, however, several stone tools in the exhibit, that actually were ancient.

Even though hominid evolution, and Lucy in particular, were the main points of the exhibit, they were really only a small part of it. Most of the exhibit was dedicated to more recent Ethiopian history, from a few thousand years ago on. As the Houston Museum of Natural Science puts it on their website, "In addition to the fossil of Lucy, over 100 artifacts such as ancient manuscripts and royal artifacts from a dynasty Ethiopians believe stretches back to the son of the biblical King Solomon and the Queen of Sheba will be on display." Most of those artifacts besides the manuscripts were painted diptychs and processional crosses. There were also a handful of weapons, baskets, and other miscellaneous artifacts. Afterwards, my wife told me that she enjoyed those paintings much more than the Lucy fossils.

After we got done with Lucy's Legacy, there was still the rest of the museum to explore, and the permanent exhibits were very interesting. I do have one gripe, though, and maybe it comes from living so many years in D.C. with the Smithsonian museums, where admission was free. But there were three other temporary exhibits besides Lucy - Lizards & Snakes Alive, Treasures from Shanghai, and Frogs! - that you had to pay an additional fee to enter, along with another permanent exhibit, a greenhouse filled with butterflies, that also cost extra. When you've got even a small family of three, those extra prices add up pretty quickly. So, we didn't go to any of those other exhibits, even though my wife really wanted to see the Chinese art, and my daughter really wanted to see the snakes and lizards. Even for members, the discounted prices are still 1/2 to 2/3 of the non-member prices, and since we don't live very close to Houston, becoming members doesn't make much sense. I suppose they have to pay for the exhibits somehow. It's just a little disappointing, when I've been to other museums, like the Carnegie Museum of Natural History in Pittsburgh, where the regular admission price lets you see so much.

Lucy's Legacy LogoOne final note - I really wanted to get some type of coffee cup or shot glass as a souvenir, but just about everything in the gift shop that had to do with Lucy had the same logo on it. And to be honest, I don't particularly like the logo, especially the way it looked printed out small on a mug. If they had just had a picture of the fossil itself, I would have bought one. So instead, I bought a copy of Carl Zimmer's book, Smithsonian Intimate Guide to Human Origins*.

I know I did a little bit of complaining there at the end of this review, but that's only so the reader knows what to expect when going to the museum. As I said, seeing the actual fossils of Lucy in person really was awe-inspiring. It was worth the 6 hour drive to get there, and I'd do it again in a heart beat.

* I haven't quite finished Zimmer's book, but I'll give a quick review after having read about 2/3 of it - I like it. It's not very in depth, so if you follow science news, you probably won't learn very much from it. But, it does have lots of pretty pictures that make it worth the price. Plus, if you don't follow science news as much as I do, or happen to know a person who doesn't know much about human evolution, it makes for a very good overview. If someone doesn't want to read the whole thing, but they're willing to listen to you explain something to them, you can still use the book, and open it up to some of those pretty pictures to help illustrate your point.


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