Esperanza. 2006 Dec 11. Ch. 10 of Zimmer. <http://development.pharyngula.org/ch_10_of_zimmer/>. Accessed 2008 Sep 06.

Posted on M00o93H7pQ09L8X1t49cHY01Z5j4TT91fGfr on Monday, December 11, 2006

Ch. 10 of Zimmer

Chapter ten closes the book with a discussion about the macroevolution of whales. Zimmer compares whales to the earliest tetrapods. He considers Acanthostega and Ambulocetus surprisingly alike. They both were ambush hunters living in shallow water. They both had long, flat heads, snapping jaws, short limbs, and powerful tails. The whales and early tetrapods both began with a minor group of animals that were probing around the edges of a new ecosystem and evolved new adaptations for their immediate conditions. These adaptations later turned out to be more exaptations for their continued evolution. They both stumbled into empty terrain and capitalized on it. The whales had the terrain of an ocean robbed of its giant marine reptiles and the early tetrapods had continents without a single vertebrate on them. Scientists argue over whether evolution happened gradually or in great leaps. The most important adaptations that the whales accumulated for water came only after they had committed themselves totally to the sea.

I enjoyed both of the books read for this class. Zimmer’s book was more enjoyable to me though as it was more a history book so it flowed. Carroll’s book was more informative on development as it actually spoke or genes and how they interact. I felt that Zimmer knew how to capture an audience’s attention better or at least an audience that didn’t have a basic understanding of biology already. Carroll’s book needed a background in biology to understand quite a bit of it yet he also explained some things for those who didn’t know biology when they wouldn’t understand the majority of the book anyway. Both books were helpful in understanding developmental biology, however, and I think they are a good addition to the class.