This is the long-awaited second edition of Jennifer Clack's classic from 2002. A lot of new spectacular fossil finds during the last 10 years must have shed new light on the issue of how vertebrate animals transformed themselves from fish to lizards.
The new edition is, as expected, clear, well written and packed with facts and information. Although the book starts out with brief explanations of basic paleontology, e.g. the meaning of latin anatomy terms, definitions of time eras, etc., the text here is not for the layman. It is a scientific treatise and sum-up of a huge volume of research work done by the author and her colleagues. The text is packed with latin names and terms, which probably will make most lay readers give up before the end. For the scientists or paleontology students it is of course a different matter.
The book has a nice appearance, although the black print in my copy tends to be a bit grayish. The illustrations are good looking, clear and very numerous, mainly depicting bones and skeletons - and closely backing up the text. Reconstructions of the animals are fewer, and little attempt is made to describe theories on their lifestyles, ecology etc. The book also contains a number of colour plates. Many of these resemble holiday shots of landscapes around fossil locations, and in several cases with the author included. A few (too few) depict specimens of actual fossils. A curious feature is that all the colour plates, which are located together between pp. 224 & 225, also are printed in black and white, throughout the book at the locations where the subject is dealt with in the text. This seems like a waste of paper.
And how, then, did we crawl ashore? In the good old paleontology books it was simple. We had a fish with some slightly arm-like fins just venturing out of the water. A little later we had a somewhat fishy amphibian doing a bit more crawling and then came a proper four-legged land-dweller. End of story. Clack shows in her book just how much more complex the picture is looking now. The amount of 300+ million years old fossil material found is enormous, and the level of detailed studies made possible is impressive. Comparable bones from a number of different species have been investigated one by one, feature by feature.
In many cases it is easy to see which features developed into the next step, but the problem is that they do not do it in an orderly way. Specimens show a curious mixture of fish-like and amphibian-like traits in different combinations. Attempts to range the species, i.e. whom begat whom, by using the so-called cladistics method, give different results depending on which part of the animals you choose to look at.
The fact emerging is that a lot of experimenting was done back then, and many of the developments happened in animals, which probably never left the water; the new features served other purposes. Accordingly, we by now have a tremendous amount of knowledge, but we still do not know exactly who went ashore for the first time.
But that does not make the book less interesting.