Customer Reviews

In Search of Deep Time: Beyond the Fossil Record to a New History of Life (Comstock books)

5 star:		(7)
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3 star:		(6)
2 star:		(1)
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Henry Gee has produced a very readable book on paleontology and evolution. This is cladistic analysis for beginners, and will interest a wide audience. I read it cover to cover in one day. It will be very interesting to see how paleontology squares off with the genomic sequences that will soon become available. Very well written and enjoyable.

This is a simple introduction to cladistics, the classification of species according to ecological relationships rather than superficial similarities or presumed position on an evolutionary tree of descent. Cladistic analysis is popular among supporters because it provides a testable way to study the relationship between species, an alternative to evolutionary story-telling for a story we were not around to witness and may never be able to reconstruct well enough from fossils.

Why is this important ? For one, it makes the definition of species potentially a more rigorously scientific affair. For another, it doesn't rely on what some critics of evolutionary theory correctly characterize as unfalsifiable wild guesses about trees of descent.

Finally, it potentially yields some rapprochement between the more reasonable proponents of creationism and critics of evolutionary theory and some of the less severe Darwinists. This is because it doesn't require us to guess at whether we share a common ancestor with apes, it provides a scientific program for testing relationships by parsimony. For this reason, it has been cited positively by critics of evoluton such as Phillip Johnson (Darwin on Trial) and Michael Denton (in Evolution: A Theory in Crisis, though far less critical of much of evolution in Nature's Destiny). On the other hand, cladistics assumes common origins of species (at least those within a given cladogram !), which makes it anaethma to the aspect of creationism which requires belief in special creation rather than just opposing the seeming meaningless and random contingency in nature that opponents of Darwinism see it representing.

An understanding and acceptance of cladistics not only heralds a revolution within biology, but potentially wider culture as well, as we would come to look at the relationship between living things in a new light. Cladistics allows us to learn from the common characteristics of closely related species without having to assume that a particular evolutionary process or path got them there, and without having to guess about the relationship of species outside the cladogram.

This looks on the surface like an obscure issue in biological taxonomy with little relation to culture, but the essence of the idea is profound in its implications. Given this, Gee presents an understated account of what could well be a very important in both scientific and political-social debates over biology as it is taught in the future.

That said, this will disappoint biologists and biology students, who having already been exposed to the idea of cladistics will find little new or original here. This book is however a very good first exposure.

This is a good book if for no other reason than its refreshing honesty with respect to paleontology. Gee attempts to pry the facts apart from the evolutionary story telling that plagues this business. On the other hand, he attempts to paint molecular cladistics as a purely objective and scientific alternative. Unfortunately, that is simply not true (not yet at least). Molecular cladistics has problems both in methodology and data (in cases of deep branches). Parsimony analysis (mentioned by Gee), for example, is giving way to other analytical methods precisely because of the problems with parsimony. Furthermore, the conclusions of cladistics are often enough at odds with the paleontology. So the story is not quite so simple. That being said, I still felt that this was a pretty good book

This book is bringing the good news about cladistics to a public that needs to be weaned from the narrative view of evolution. In this older approach, paleontologists used fossils to weave a story of species mutating into species as the relentless pressure to adapt pushed them along. The author claims that the vastness of Deep Time (that is, geologic as opposed to historical time) does not allow such narratives to be strung together by using isolated bits of bone, often separated by vast numbers of generations. Or rather, he claims that such stories are untestable, that there simply is not enough context in these widely scattered finds to build any coherent picture, to make predictions, and to verify them. In other words, it is not possible to proceed scientifically. One may have a good story as to why, for example, Triceratops had a crest and horns, but there is no way to verify that it's better than anyone else's rival story. So we're awash in "just-so stories" that advance our real knowledge not a whit.

Enter cladistics. Cladistics does not speculate on why the elephant has a trunk but, instead, uses that feature to help define the clade to which elephants belong, and to relate it to all the other clades, from worms to whales. Cladistics is an important advance in classification method, which makes it an important advance in knowledge, because it provides a new lens to look at old facts. It is a sometimes bracing antidote to too much story-telling with no reality checks. So the topic is an important one. It's too bad that the author fails to grapple with it.

I had the feeling of treading water as I read this: not getting anywhere and unable to get any purchase. The few diagrams are annoyingly uninformative, and Gee apparently is uninterested in actually illustrating anything that would support his words: though his points are mostly visual ones there are no anatomical diagrams. He never really shows just why narrative is unscientific - although he asserts it almost continuously - but more importantly, he never gives the reader any sense of how cladistics can illuminate, of where its particular power lies.

Henry Gee is not without charm - this book is heavy on the atmospheric evocation of person and place, and I cannot dislike anyone who heads so many chapters with apt and esoteric quotations from Borges. But he just doesn't SAY anything, not really. When one is done with this book, one has no telling counterarguments to use down at the bar when the other guys are pooh-poohing cladistics and roaring out their ad-hoc adaptionist fantasies.

I chose it because the blurbs were from individuals, and impressive ones at that. But, of course, paleontology is an exclusive club, and many of these same folks appear in the acknowledgement section. Perhaps what they liked about the book was that it talked about the profession a lot, and about individuals they knew. In that respect the book was a pleasant read, as it introduced a cast of characters, human and fossil, and tried to make a narrative (!) using them. But that sort of thing should be the sauce, not the entrée.

Henry Gee is like a hustling salesman. You can picture him on late-night TV flogging veggie choppers. While firmly disparaging his competition, he regales you with the wonders of his product. In this book, the competition is "adaptation" and "convergence" in evolution. The product is "cladistics". It's a new way of looking at the physical traits of Nature's plants and creatures and their evolutionary relationships. Gee is an expressive and persuasive writer. His foundation in palaeontology gives him an intimate knowledge of the science. His salesmanship, however, tends to the excessive. Like the TV promoter's pitch, when you buy the product and examine it closely, you find you've paid for more than you receive.

Gee's title, and the premise of cladistics, is that we can't see very far into the past. Historical continuity, with documents, paintings, letters and memories perhaps reinforced by family ties, doesn't grant us much depth of vision. How much, he asks, do you know about your great-grandparents? With fossils, he stresses, drawing "family" lineages is a process imbued with imprecision. He scorns anthropologists claiming to see a traceable picture of Homo sapiens' ancestry from to some hillside tooth fragment from the Rift Valley. He deems all that remote past with its scattered fossils so wonderfully explained by palaeontologists "deep time". Which, of course, covers all evolution's history.

The author's arguments as he builds his case are multilevel. He doesn't trust stratigraphy to pinpoint relationships in time - a species "A" may have survived to live parallel to a new branch "B". Yet our fossil sequence may show the "A" living later than "B". That alone, he claims, renders any assessment of adaptations suspect. Physical traits we see in fossils are often labelled "pre-adaptations" since it appears "primitive" traits may have gained in complexity over time to become more useful. Gee dismisses these sequences as unsubstantiated. "Testable" theories of evolution's process become meaningless. This is hardly news - little in the fossil record is "testable". In any case, cladistics wholly ignores evolution as a "process". It is a series of snapshots of "events".

Instead of "relating narratives" as he accuses his fellow palaeontologists of doing, Gee wants them to more closely study physical relationships. What characteristics can be identified, and how do these relate among species? Dogs, cats, and cows are clearly four-legged animals with vertebrae. So are fish, birds and crocodiles. Cladistics allows you to portray life in new arrangements of "cousinship". Gee declares these new relationships allow us to see life "as it is", not how we "want it to be". The relationships are graphically presented in what are known as "cladograms". For Gee, these diagrams portraying characteristic similarities are more meaningful than speculative diagrams about descent lineages. They also, it turns out, support Stephen Gould's notion of "punctuated equilibrium" over the "adaptationist programme" of neo-Darwinism.

Gee wants to abandon "traditional" fossil hunting and interpretation with a "revolution" [his term] - a turnover to cladistics. His proposal to banish "inference" from accumulated fossils and their context and replace it with a strict methodology is not sound. Traits, no matter how ancient or enigmatic, represent the lifestyle of their possessor. Sciencists may make proposals about how a species lived that are later overturned by new evidence. Cladistics acts as a tool to assess those evaluations, not overturn them. The book is valuable for explaining how cladistics can be used. Gee's strident tone and overassertive style dulls its cutting edge, however. [stephen a. haines - Ottawa, Canada]

This is a concise introduction to cladistics, a method of taxonomic classification that emphasizes evolutionary relationships. Because this method involves fewer assumptions than traditional and somewhat impressionistic paleontologic reconstruction, it is narrower but more powerful. Gee emphasizes how cladistic methods have put paleontology on a scientific footing and emphasizes equally the limitations of this method and the ultimate limitations of our ability to reconstruct the history of life. This book is also a nice story about how science is done and how change occurs in scientific communities.

The title of "Deep Time" refers to the immense gulfs of time that separate the major events in evolution. The best known of these is the gap of 65 million years between the disappearance of the dinosaurs and the present, but this only one of many, and by no means the largest. More important than the size of these gaps for Henry Gee's arguments, however, is their emptiness: there are extremely few fossils to provide landmarks, and many of these are damaged, incomplete, and in general unsatisfactory. "Incomplete" is, indeed, a weak word to convey the idea that one worn fragment of a jawbone may be all there is for trying to reconstruct a whole animal. Fossils thus offer nothing that resembles a historical record. Gee considers that trying to reconstruct evolution on the basis of so little information requires far more rigorous methods than those that were in general use before the development of cladistics.

Most of his book, therefore, is an attempt to convince readers of the rightness of the cladistic approach, in which the only consideration is the branching of lineages into separate lines of descent. In this scheme it makes sense to classify organisms into clades, where a clade contains only those individuals that are derived from a single ancestral branchpoint. This sounds rather abstract, and in many accounts it is, but Gee does a good job of explaining what he means in a comprehensible way. He is particularly interested in fish, and they illustrate well how the cladistic approach has transformed ideas of how organisms should be classified. According to him, a fish is something you buy in a fish shop, and has no deeper meaning than that. This is because some "fish" are more closely related to mammals than they are to other "fish". As a more familiar example, there is now scarcely any doubt that chimpanzees and gorillas are much more closely related to humans than they are to other apes, orang utans and gibbons. There can be no clade, therefore, than includes all these apes but does not include humans.

Although in general Gee's argument is clear and convincing, he oversimplifies when he tries to justify the cladistic method in terms of parsimony -- the guiding principle that the preferred reconstruction of a history is the one that involves the fewest hypothetical events. The problem here is that he says far too little about the rooting of phylogenetic trees. The example that he uses is the set of three individuals that consist of himself and his two cats, and he claims that parsimony requires a classification in which the two cats are more closely related to one another than either of them is to him. This conclusion, however, owes everything to common sense and nothing to parsimony, because in an unrooted tree with only three branches exactly the same number of events are needed to connect the tree individuals regardless of which of the three one thinks is the least closely related. Because cladistics is concerned only with the branchpoints and not with the lengths of the branches, classifying Gee with one of his cats, but with a very long branch linking him to the branchpoint, is just as parsimonious as a tree that classifies the two cats together.

The book stands somewhat apart from many popular books on evolution in that it is much more about anatomy than about behaviour or molecular genetics. Both of these last two get mentioned, of course, but really what interests Gee the most is what we can learn from fossils. Nonetheless, he does not expect readers to be able to interpret fossils themselves, only to believe that the experts who do this know what they are talking about. As a result, the emphasis on anatomy does not prevent the account from being thoroughly readable. As I have mentioned, Gee is interested in fish, and this illustrates another feature that is unusual in popular books, that it has far less about humans and hominids than many books: the beginning and end are mainly concerned with human origins and evolution, but much of the middle part is not. Likewise he is much less obsessed with dinosaurs that many popular writers on evolution appear to be.

The author is besotted with his cat, a cat named Fred. No chance of dropping Fred's name onto a page is missed. Gee seemingly cannot speak of a chordate, or a tetrapod, without adding a parenthesis ("you, me, Fred the cat"), just to make sure the reader grasps the concept. The book needs illustrations beyond the few rudimentary cladograms, all attributed to a mysterious Mr. Xeridat. A few good ideas are introduced in the opening chapter, namely, the concept of parsimony, in selecting conflicting possible relationships between species. But then we get back to Fred the Cat. Gee states that the Megatherium (an extinct ground sloth) was twice as heavy as a bull African elephant. From what I can find on websites, the masses are indeeed in a ratio of two to one, but in favor of the elephant, about three tons to seven. The only reason I looked this up is that it seemed so unreasonable an assertion. I urge caution in accepting all that Gee says here.

I agree with James McCall's review. I don't regret reading the book, though it didn't teach me much about cladistics that I didn't already know. However, I found the first several chapters tedious, repeating the same criticisms of "evolutionary story-telling" over and over. I think it would have been much more effective if Gee had given more examples of how cladistics better illuminates interesting evolutionary questions than the traditional approach.

Regardless of the limitations of story-telling in "deep time," it exists because people want to know, for example, why and how some group of fishes gave rise to tetrapods, or how some group of ancient proto-hippos (hypothetically) evolved into whales. Gee's extreme methodological purism (as I understand it) would have us ignore these interesting questions as unanswerable. It seems to me that a more constructive approach would be to have cladistic reconstructions set limits on and help decide between conflicting evolutionary stories, while acknowledging their highly provisional nature. The process may not be as rigorous as a cladistic analysis, but if enough hippopotamid fossils from around the time of divergence between whales and hippos were discovered, one or more evolutionary/geological/ecological hypotheses could be constructed to describe how it occurred. The hypotheses would have to be consistent with the geological and geographical context of the fossils, and would be subject to revision or winnowing as new fossils are found. This is still science.

I liked most of the book. It held my attention and I did read all of it. This gets a book 3 stars. It gets 4 stars for not dwelling on charismatic dinosaurs for a huge length of time and discussing lesser known areas of life's time on this planet. However, it was simplistic and I kept expecting it to build on itself and come to a grand conclusion. It stayed simple. I would have loved this as a textbook or supplemental text when I was in college.