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6 of 7 people found the following review helpful:
5.0 out of 5 stars
A humerus tale . . ., 23 May 2005
This review is from: Gaining Ground: The Origin and Early Evolution of Tetrapods (Life of the Past) (Hardcover)
. . . plus some ribbing, vertebrae and shoulder bones. But it's the skull that captures the most attention. The multitude of variations that occurred as animals moved in delicate steps from water onto land that make the story most interesting. And Jenny Clack's story of our four-legged forebears is a wondrous tale. Ever since Charles Darwin explained the nature of life's evolution, the question of how sea creatures moved to the land has been an enigma. Consider the many issues involved: walking, breathing air instead of filtering water, hearing in air instead of water, how to feed - and where, and protecting eggs. Clack shows how these topics were addressed by slow, incremental changes in body plan, with changes in one area integrated with those in another. Walking on land meant not only building bones strong enough to support the body, but muscles to drive them. The humerus, the single bone in your upper arm, not only had to be stronger, it had to have joints for a new form of movement. A stride is far different from the flapping of a fin, so the paddling fin had to change. Clack discounts the older, simpler views that the "lobe-finned" fish just developed better "legs". Moving from the sea requires more than just crawling up the beach. There had to be an intermediate step. Clack finds that step in brackish lagoons and shallow, meandering rivers. There, the new four-legged creatures learned to walk on silty soils and learn to mix air and water breathing methods. It was a reinforcing cycle as the change in surroundings developed new capacities. Diet went from fish to insects. No longer able to simply swallow prey as fish do, tetrapods began feeding on insects and their own smaller cousins. That meant biting and chewing, requiring stronger jaws and specialised teeth. Skulls once short and narrow became wide and flat. This reorganising of the entire skull required new musclature for support. The more time on land, Clack shows, meant not only stronger legs, but a sturdier backbone. Ribs developed that held muscles for breathing. Although the earliest tetrapods likely gulped air as a fish gulps water, before long they were using their nostrils to fill lungs. As should be obvious, this isn't a simple narrative. The fossil bones are meticulously detailed - when they are available. Clack's task is rendered more difficult by the paucity of fossils. She has been lucky in her own finds in Greenland and Scotland. Others have encountered Carboniferous fossils in the Ohio Valley, Nova Scotia and Australia. The real treasures should be in coal seams where plant remains have become burnable stone. However, mining operations leave little opportunity for discovery. What has been found has often been misinterpreted. In order to depict what happened to tetrapod bodies over time, she is meticulous in describing individual bone types and how they changed. She helps the description with photographs and a wealth of line drawings. Still, this isn't a book for the uninitiated. It requires careful reading and no little back-flipping of the pages. The endeavour is well worth the effort, however. Clack has established an new foundation for understanding where and how creatures like ourselves originated.
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9 of 11 people found the following review helpful:
5.0 out of 5 stars
THIS IS THE SCIENTIFIC BOOK!, 10 Feb 2003
By A Customer
This review is from: Gaining Ground: The Origin and Early Evolution of Tetrapods (Life of the Past) (Hardcover)
At the first place when I looked this over, I had a presage that this must be an interesting one, and now I’m at about a half of the total pages, and betrayed even in a better sense. This has turned out to be a superbly written book and one of the most exciting and intriguing one. Basically the theme that this book treats, by itself, has unfathomable interest. There may be two ways to describe on the history of fish-tetrapods transition. One is focusing on the chorological discoveries and explains on them in an adventure story touch. The other is rather orthodox in textbook like form. The author employed the latter style. However, it’s not boring at all because it’s well composed and organized. And speaking of methodology, her augment is very conservative well based on fossil records and related provinces such as embryology and speculation based on existent animals behaviour. It’s written businesslike and dry expression, not too much exaggerated, even so it’s really fascinating. Although to the complete lay reader, due to the jargons, it looks like complicated, it worth tackling. Many illustrations would help you. And for those who are interested in prehistoric animals and have read some, it shouldn’t be so difficult. As it may sound strange, the author does not refer to the term “amphibian” for this unique creature. And, instead, she applies “tetrapod”. Which means, in spite of their possible life style, she takes them different type of creature clearly distinguishing from the current counterpart. I suppose it’s quite reasonable. This is a superb book!
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5.0 out of 5 stars
How we crawled ashore, 17 May 2010
This review is from: Gaining Ground: The Origin and Early Evolution of Tetrapods (Life of the Past) (Hardcover)
This is clearly a professional textbook, written in scientific jargon, and without a detailed knowledge of anatomical terms the lay reader will quickly be left behind by some of the passages.
Nevertheless, for the interested amateur the book offers a fascinating window to the time when vertebrate animals left the sea and established themselves on land. You get a clear impression of the complexity of a fish skeleton and the countless changes that gradually turned it, step by step, into something resembling a lizard. Parallels to modern-day animals, like lungfishes and salamanders are drawn whenever relevant, and the reader will realise just how unique the lungfish is, compared to all other living animals.
It is amazing how much fossil material has been found to shed detailed light on all these 350-million-year old animals, illustrating the long development from fish to 4-legged animal. Not as one continuous line, but in fits and starts, and with many detours to other combinations of the characteristic traits of these two animal kingdoms.
The book is packed with information, each of the 331 pages contain a lot more words than normally seen in one page. To balance, however, the book carries a large number of very nice illustrations of bones and bone comparisons, supplemented by animal reconstructions.
The book was written in 2002, before the spectacular finds of Tiktaalik, the new much touted "missing link". It would be very interesting to see, in a new edition, how Jennifer Clack would fit this one into her picture of this period of animal evolution.
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