Thursday, January 14, 2010

Book Review: Evolution - What the Fossils Say and Why It Matters

This book ended up having a slightly different focus than I expected. Dr. Prothero is a well respected expert paleontologist, specializing in fossils of large mammals. In his book, Evolution: What the Fossils Say and Why It Matters, Prothero goes beyond the well known fossils to showcase the fossil evidence for Evolution. When most people think of fossils they think of dinosaurs. However there are many, many other fossils, in fact over 100,000 different species and more being discovered every day.

Early in the book, he has an interesting section on cladistics. I remember in school we learned about different types of creatures and how to organize them into logical groups(for example reptiles, fish, amphibians, birds, and mammals.) All of this is now obsolete. In fact it was obsolete when I was learning it in school. For example, we now know that crocodiles are more closely related to birds than they are to other reptiles like lizards and snakes. (Just in the last week, an interesting study has come out that shows that alligators and crocodiles breathe like birds.) The desire is to include the species and all descendant species in a single group (mono-phyletic). So fish no longer makes sense as a group since all land vertebrates are descended from them. Same for amphibians. The coolest part about the whole thing is that not all the dinosaurs disappeared. That sparrow outside your window is part of the dinosauria group.

In general Dr Prothero has organized the book to cover fossils that are more distant from us in time and genetics first. His discussions of invertebrate fossils precede those of early vertebrates and he ends his discussion with a look at hominid fossils. This book was written before this year, so his knowledge of "Ardi" is out of date, but he does have an interesting section on "Tiktaalik".

At times it was difficult reading, since there is so much detail. However when covering a field as broad as this, I am not sure how he could have done it differently. My main annoyance was the constant harping on creationist authors. Yes, they are frequently quoting out of date sources. Yes, they are usually speaking without having even looked at the fossils. I get it. I don't think it needed to be mentioned every single section of every single chapter. I am guessing he is tired of creationists distorting his field of research. I sense a concern with the deterioration of science education in America. However it did interrupt the flow of the book.

One key item that sticks out is how much attention to detail is required to separate out differences and identify which group a fossil belongs to. Usually only the conclusions make it to the popular press. However there are detailed observations that support those conclusions. This leaves the impression that scientists are just guessing. For this reason, I would recommend reading this book.

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