Aquagenesis: The Origin and Evolution of Life in the Sea

Rating:
Summary: Technical, for experts
Review: 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.

Rating:
Summary: Aquagenesis: The Origin and Evolution of Life in the Sea
Review: 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.

Rating:
Summary: Decent overview of most marine animal evolution
Review: 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 white illustrations. I found his coverage of the coelacanths particularly interesting, noting some of the mysteries that even the living fish present (such as the function of their "rostral organ" - perhaps it is used to detect weak electrical fields). I also enjoyed his section on bioluminescence, something that still presents an enigma to biologists (such as how the luminous bacteria that some species depend upon to light up in the ocean depths are acquired, particularly if they cannot exist outside of their host and the young of the species are not born with the bacteria already present). Also worthwhile was Ellis' reporting of the Bear Gulch Limestone Formation of Montana (dating back to 320 million years ago from the Mississippian), a truly excellent fossil site that has yielded 4,500 specimens representing 113 species of fish, many beautifully preserved. A number of unusual fossils have been found there, such as the shark _Damocles serratus_, so named because of a dorsal spine with a serrated edge underneath, one that hung over the head of the animal, not unlike the sword that hung over the head of Damocles in ancient Greece.

Although not marine animals, the evolution of vertebrate limbs is covered as well. Ellis summarized the writings of Jenny Clack and others, noting the theory that the early amphibians used their legs not for terrestrial locomotion but for movement in the water or on river and lake bottoms, and that the study of the origin of tetrapods and the invasion of land by vertebrate animals are two issued that (according to researchers E. B. Daeschler and N. Shubin) need to be "decoupled."

Reptiles aren't given as much coverage as one might think. While sea snakes, crocodilians, and sea turtles are very well covered (the latter with a nice rundown of living species), the Mesozoic marine reptiles are given short shrift. Ellis has said in his subsequent book on Mesozoic marine reptiles, _Sea Dragons_ that he cut them out of _Aquagenesis_ due to space requirements.

The evolution of penguins and particularly marine mammals - sea otters, seals, walruses, whales, dolphins, porpoises, manatees, and dugongs - has some of the best coverage of any subject in the book. Particularly interesting were the problems with the pinnipeds (seals) in the fossil record, how they appear already to be fairly well specialized in the Miocene (about 24 million years ago), lacking much in the way of transitional forms; also the possibility of separate ancestors for the eared seals and walruses (perhaps a bearlike progenitor) and the earless seals (maybe an otterlike ancestor).

Near the end Ellis presented the controversial Aquatic Ape theory that humans descended from an ancestor that may have spent a fair amount of time in shallow coastal waters. Citing evidence presented by Alister Hardy and Elaine Morgan that man may have had an aquatic past - the presence of large amounts of subcutaneous fat, hairless bodies, the only terrestrial mammals that can hold their breath, that humans can swim almost from birth, noses well adapted to keep out water from nasal cavities - Ellis also recounted the opposition this theory has met.

Though I found a few errors in the book, overall it was enjoyable.


Rating:
Summary: A history of sea life and its evolutionary processes
Review: 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.

Rating:
Summary: Aquarevelations
Review: I bought this book after reading the author's previous "Search for the Giant Squid". Giant Squid was very good. This book however,is a double edge sword, it has great illustrations and the topics look interesting, BUT many facts are wrong!

Examples: page 2, states that the Dinosaurs "disappeared hundreds of millions of years ago" (65 million years would have been correct.) Page 117 identifies the Mississippian Age Bear Gulch Formation as Devonian Age. Page 51 and 52 and 53 list Horseshoe crabs as dating from 200 million years ago but there are well known horseshoe crabs as old as 370 million years old!
Page 53 also lists Aglaspids as being horseshoe crabs when they are not considered to be.

I teach, and the accuracy of material is important. I don't want to present ideas to my students if they aren't right. The book is interesting, but the errors I see at a quick skim make me pause.

Rating:
Summary: Aquarevelations
Review: I bought this book after reading the author's previous "Search for the Giant Squid". Giant Squid was very good. This book however,is a double edge sword, it has great illustrations and the topics look interesting, BUT many facts are wrong!

Examples: page 2, states that the Dinosaurs "disappeared hundreds of millions of years ago" (65 million years would have been correct.) Page 117 identifies the Mississippian Age Bear Gulch Formation as Devonian Age. Page 51 and 52 and 53 list Horseshoe crabs as dating from 200 million years ago but there are well known horseshoe crabs as old as 370 million years old!
Page 53 also lists Aglaspids as being horseshoe crabs when they are not considered to be.

I teach, and the accuracy of material is important. I don't want to present ideas to my students if they aren't right. The book is interesting, but the errors I see at a quick skim make me pause.

Rating:
Summary: Very well done!
Review: 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

Rating:
Summary: Technical, for experts
Review: I read the author's very good "Encyclopedia of the Sea" and hoped this would be equally entertaining. It seems this book is more for people who already know a lot about ancient life. There are illustrations, but not enough as the author will describe bizarre, one of a kind creatures, but then not have a drawing of it. He describes contraversies about where a fossil belongs in the classification tree or if a new branch has to be added. I found the "Shape of Life" video much more interesting. This book seems to be a scholarly work, with many quotes and credits given, for other scholars.

Rating:
Summary: Technical, for experts
Review: I read the author's very good "Encyclopedia of the Sea" and hoped this would be equally entertaining. It seems this book is more for people who already know a lot about ancient life. There are illustrations, but not enough as the author will describe bizarre, one of a kind creatures, but then not have a drawing of it. He describes contraversies about where a fossil belongs in the classification tree or if a new branch has to be added. I found the "Shape of Life" video much more interesting. This book seems to be a scholarly work, with many quotes and credits given, for other scholars.

Rating:
Summary: Explains The Origin and Evolution of Life in the Sea
Review: More lucid science writing from Ellis (Imaging Atlantis, 1998, etc.), who this time cuts a broad swath through the history of marine animals. "This book is about animals whose ancestors came out of the sea and whose descendants returned to it," writes the author. That and a whole lot more, for while almost every aspect of paleontology is rife with ambiguous, speculative, and contentious theories-and Ellis gives many of them sufficient air time in these pages, such as changes in genetic structure to lines of descent-there is no contesting the complexity of the fossil record. And the glory of species complexity is on full display here. From the earliest creatures of the vents, the breeding grounds created by the spreading of the seafloor and strong candidates for the deep-ocean location of the origins of life, to Elaine Morgan's evidence pointing toward an (at least semi-) aquatic ancestor of humans-and she isn't talking about jawless fish, but rather an aquatic ape-Ellis covers an incredible land- and waterscape. There's a rogue's gallery of toothy, spiny creatures (sharks with teeth all over their heads, others big enough and happy to eat a horse) and an equally long list of sideshow marvels, including the wonderful hagfish, which "can emit gallons of nauseating, toxic slime." The theories tendered for the evolution of these creatures are often as fabulous as the creatures themselves: Certainly the descent of whales from giant wolves falls into that category, but less sensational are the beard-pulling contests between academics, such as the Gould/Conway Morris feud. Then there are all the questions that remain unanswered, far more than those with answers, beginning with: How did it all start? Ellis samples from all these topics with the enthusiasm of a child let loose in a candy shop. As entertaining as a three-ring circus, and as scholarly as any intellectually curious lay reader would wish for.