Aquagenesis: The Origin and Evolution of Life in the Sea

this is a great book to read about the evolution of sea organisms evolving into land animals. very good black and white drawings by the author.

Author Richard Ellis in _Aquagenesis_ originally sought out to document in a popular science format how the ancestors of marine mammals, reptiles, and birds returned to the sea. In the process of researching the book Ellis became intrigued with the phenomenon of life in the water, from the origin of life itself - which likely took place in water - to the evolution of marine invertebrates and fish. As result, the scope of the book widened considerably. Ellis recounted some of the theories about the origin of life. The main one he reviewed was that life may have first appeared around hydrothermal vents in the deep sea, perhaps from impact generated hydrothermal systems (as for a period of about 200 million years, very roughly between 3.9 and 3.8 billion years ago, the Earth may have experienced as many as 10,000 impacts by extraterrestrial bodies). Not only would such environments have been plentiful, but they would have aided by virtue of high temperatures the creation of organic compounds and would have been places shielded from ultraviolet radiation. I found fascinating his discussion of the Ediacaran (or Vendian) fauna, the oldest recorded animals, fossils of soft-bodied organisms that lived between 565 and 535 million years ago. The Ediacaran fauna is unusual; many of these organisms come in strange shapes and sizes, have no recognizable fronts, backs, heads, tails, circulatory, nervous, or digestive systems. Many of them vaguely resembled modern jellyfish, though they appear to have been benthic (or bottom-dwelling) organisms ranging in size from a few millimeters to a meter in diameter. One researcher (Gregory Retallack) according to Ellis believed that the Ediacarans were not soft-bodied animals at all but rather a type of lichen, with a sturdier structure made of substances not unlike chitin. Another paleontologist, Adolf Seilacher, wrote that the Ediacarans are unrelated to any existing lifeform (calling the Ediacarans as a group the vendozoans) and postulated that their structure was rather like that of an air mattress. The much discussed Burgess Shale fauna is well covered in this book, along with the highly publicized disagreements between the late Stephen J. Gould, who felt the bizarre fauna represented many weird, wonderful, failed experiments, and Simon Conway Morris, who felt that researchers had focused too much on the differences rather than the similarities of the Burgess Shale animals to known species and phyla. Ellis provided a good summary of squids, octopi, ammonites, belemnites, and the nautiloids (including the five existing species of nautilus), though much of his short section on trilobites quoted or paraphrased (with due credit) Richard Fortey's excellent book _Trilobite_. I think he could have been much more thorough though in his very brief discussion of the eurypterids (sea scorpions). The evolution of fish is given wonderful treatment, accompanied by (as is much of the text) by Ellis' skillful black and

I have a copy of this book, and I would highly recommend it to anyone who wishes to know more about animal history, before, during and after life emerged from the ocean. As a simple lay person without a biology degree, this book has been a great asset to me personally when seeking answers about primitive creatures. This book introduced me to many creatures I'd never heard of, and indepth information on ones I had. It's one of my favorite books and much treasured. -Sharon Mooney, NC, USA

Aquagenesis: The Origin and Evolution of Life in the Sea Written by Richard Ellis is quite simply a very fascinating book. A book that covers life in the sea from small little creatures too a shark that can swallow a horse whole.Aquagenesis is a book that traces the phylogenic origins of aquatic life further and further back of not only the ancestors of the living whales, seals, manatees, sea turtles, sea snakes and penguins that were terrestrial, and their living descendants all returned to the sea, to one degree or another. But, this book is not without opinion and it plays a considerable role, mainly because interpretation is so much a part of this book, opinions of others are relied on via their published works or directly. But, this isn't a book so much about whales, seals and manatees as it is a book about the beginning of life in the sea.What I found interesting in the book is how the author explains how life and a phenomenon known as sea-floor spreading where cracks or rifts are created in the crust of the Earth are connected. Plate tectonics causes these rifts and minerals spew into the water in clouds known as "Black smokers" that eventually dissolve and disperse into a water columns and life is found where you would think none could exist.Also, the author takes a look at some of Stephen Jay Gould's work from "Wonderful Life" about the Cambrian Shale deposits known as the Burgess Shale. A review of the fossil biota brings the differences in interpretation and conclusions, but the major battle lines have been drawn. I must say that this book takes the reader on a ride of mystery from the first microbes to jawless and finless creatures to a possible aquatic ape that could be mans ancestor.Some of the creatures we read about in the book are quite bizzar and the author has supplied detailed drawings that bring these animals to life. Sharks with teeth on their backs and others had teeth as large as your hand, all making for wonderful reading. I liked the author's narrative style in this book as it was straight forward and easily readable. The subject matter of the aquatic ape is covered toward the end of the book and is quite interesting.Aquagenesis is a book about life in the past, but also how that life shape life today making for some compelling fascinating reding.

How did early life evolve in our oceans, and how did they evolve from the sea to become land creatures? Aquagenesis provides a history of sea life and its evolutionary processes, combining the author's illustrations with a scientific examination of the origin of life in the sea.