Customer Reviews

Sudden Origins: Fossils, Genes, and the Emergence of Species

5 star:		(7)
4 star:		(1)
3 star:		(5)
2 star:		(2)
1 star:		(1)

 

 

Schwartz spends most of his book on the history of evolutionary theory, which is fine from the perspective of a historian of science, but then there isn't much of the book left for development of newer ideas. Pages are spent on Linnaeus but next to nothing on cladisitics; much detailed attention is given to detailed reports of the first hominid fossils found, even to Piltdown, but more recent findings are hardly mentioned, surprising given that he is even now editing an authorative volume with Tattersall on hominid fossils. However, credit is due for developing the thesis that the discontinuous fossil record is due to the relatively sudden emergence of species from changes in regulatory molecules such as the homeobox genes. Rudolph Raff, in The Shape of Life (an excellent book which Schwartz quotes) previously developed the thesis that macroevolution of body plans was dependent on these genes, but did not emphasize the discontinuous fossil record. Although we don't get to a discussion of the new ideas until the last 10% of the book, nonetheless, this whole area of evolutionary developmental genetics is of such fundamental importance that the book is worth reading. In the relatively near future, with new fields such as comparative genomics (comparing entire DNA sequences of one organism to another), and computerized analysis of developmental expression of complete sets of cellular proteins analyzed on biochips, the promise of reconstructing, at a molecular level, the evolutionary history of life on earth has begun. I'd also like to take issue with the reviewer who thought Schwartz "savaged" Darwin. He does not, though as part of his detailed review of the early debates on evolution he quotes scientists who do attack Darwin's ideas. And although it's true that actual research details on speciation and changes in homeobox genes are at an early stage, and that Schwartz is not a researcher himself in this area, again I think he's on the right track. For example, see the article by Ting et al. (Science 1998 282:1501)about a rapidly changing homeobox gene linked to speciation in Drosophila. Overall, I think the book is an important one, but could have been much improved as a scientific text by giving a broader picture of newer data and less emphasis on historical personalities, though as written it is designed to appeal more to an educated lay audience than to the professional.

This is an excellent book that provides a reasonable introduction and much historical context to the concepts behind a class of theories of speciation that are gradually becoming less controversial.

The notion of cumulative gradual change in allele frequencies as the only source of variety has been a thorn in the side of serious biology for some time. Not least because it leaves the door open to claims that speciation itself is "improbable" in higher species. Richard Dawkins' brave attempts to rescue biology from "Mount Improbable" may very well turn out to be partly an exercise in futility.

Schwartz joins a number of recent authors and researchers to face head on the challenge of improving our understanding of evolutionary biology by recognizing that it makes perfect sense of much otherwise confusing data to allow for sudden "saltational" changes in species. As hard as it remains for many to swallow, S.J. Gould was probably right about much of this, and deserves credit for bucking the "received" view of Darwinism.

This book is disappointing however, in that it seems to revel in telling the history rather than describing the new concepts. There's just so much politics behind this issue that authors can't seem to avoid the temptation to add their own spin to the history in every book. But that part has been done already. Sterlny and Griffiths' "Sex and Death" does a great job of discussing all of the various chinks in the armor of the received view of how evolution works, without spending so much time interpreting intellectual history yet again.

The new part that is most exciting is the details of how regulatory genes work, their duplications and mutations, and the role they play in speciation. There is sadly relatively little of that in Schwartz's otherwise useful presentation.

A very recent release in the U.K. by Mark Ridley, "Mendel's Demon," looks like it handles similar deep questions but goes far more deeply into the genetics that forms the foundation for theories of sudden origins and other alternatives to simple cumulative gradual interpretations of Darwinism.

One point I wanted to make as a comment to a previous review. It was claimed at one point that this kind of theory is more congenial to the way many people view creation by God. That's something I think is a welcome sign. But they also commented that "creationists" is a meaningless label, and it seems to me that claim is simply nonsense. "Creationists" deny that speciation occurs at all, at least in the origin of humans. They don't argue that it could only occur suddenly. Whatever else they may accept or reject from evolutionary biology or genetics or paleoscience, it seems to me that they cannot accept that humans were not special creations of God separate from other animals. The United States is divided into those who find the close relationship of humans and apes ridiculous and those who pretty much take it for granted. That's not an easy line to cross, much less pretend it doesn't exist.

It would be very heartwarming and reaffirming to my faith in human reason of some people who consider themselves "creationists" were to find the theory of sudden origins in this book an acceptable version of evolutionary theory, but I'm not going to hold my breath waiting for it to happen.

The difference is critically important scientifically because the power of evolutionary thinking is not in whether we happen to be related to apes, but in the value of being able to apply adaptational thinking to species characteristics and describe and predict how characteristics relate to environments. Creationist interpretations deny the central concept of evolutionary thinking, that natural selection explains adaptation. The details of how it works and where other explanations supercede adaptational ones is what is left to ongoing research to discover.

That's where Schwartz contributes best to the literature, by placing "sudden origins" into its rightful historical context, (though I don't agree with some of his intellectual history in the medieval period). This is not something that creationists can honestly take any credit for, or honestly use in support of their agenda it is a theory of speciation not a denial of speciation.

This is a very important source of information both as to the history of the Neo-Darwinian Synthesis and the recent discoveries of regulatory hox genes and the light they throw on the riddles of speciation and large scale evolutionary change. The realization that major morphological changes do not in fact occur in the fashion of microevolution (as presented by traditional Darwinists), due to the effect of homeobox genes, is a revolutionary discovery and confirmation of the importance of the developmental tradition moving in parallel to standard Darwinism. This data creates a foundation for the various theories of macroevolution and punctuated equilibrium proposed almost a generation ago but still sidelined by the Darwinian mainline. The book contains an invaluable review of paleoanthropological theories, issues of neotonous evolution, and the various genetical theories of Mendelism, from de Vries and Bateson, to Haldane, Wright, and Fisher. The views of Goldschmidt, and his near miss of this new perspective, is also treated. This confusing history of Mendelism sorted out is invaluable, and shows how cogent (in part) where the intimations of Bateson and Morgan. The new perspective both confirms the concept of 'macroevolution' while suggesting this can be seen as a microevolution of regulatory genes, a point open to debate perhaps. The next mystery is the evolution of these complex sequences of development. But that does not distract from the great usefulness of this account. One can dispense with much of the erroneous literature on evolution, a great saving in brain space. The endless debate over the slow evolution of the eye, etc, that went on and on and drove all parties batty is hopefully over if we know the right combination of homeobox genes will control the development of this and other organs. Times are changing in Darwin land. Highly recommended.

Despite the intellectual pretensions of this book, Sudden Origins is poorly reasoned and is based on a naive understanding of much of the science on which it is based. It is filled with irritating errors. Most organisms stop growing when they reach sexual maturity, but many do not. Chert and flint are not volcanic rocks. The fossil record cited by Schwartz is limited almost exclusively to hominid specimens. While this might be expected from a paleoanthropologist, it is rather limiting for someone discussing the evolution of species. Schwartz's understanding of genetics seems to be limited to the high-school version of dominant and recessive traits, a brilliant deduction for Mendel, but a gross oversimplification as we approach the 21st century. The importance of mutations in the genes regulating development, such as the homeobox genes, is an interesting subject of current research, but the effects are far more varied and complex than Schwartz indicates. Such mutations can sometimes cause major developmental changes, but this does not imply that gaps in the fossil record are explained by this type of mutation. Given his own lack of sophistication in modern genetic, developmental, and evolutionary work, Schwartz's savaging of Darwin is in particularly poor taste. Darwin developed the idea of natural selection in spite of having limited understanding of the underlying mechanisms of change. This makes his achievement more intellectually impressive, not less. Darwin mastered the scientific knowledge of his time and built uppon it. Unfortunately, the same cannot be said of Schwartz.

One of the great strengths of this book - a fascinating addition to the literature on evolution - is that it offers a highly readable account of a complex scientific theory and its background, and thereby has appeal both for the expert and the layman (layperson?!) I am certainly no expert in evolution or genetics, but I do find the subject very interesting, and appreciated the clarity of the author's style, and the easy way in which one could trace the journey through man's supposed evolution down the various, often divergent, paths of scientific discovery.

I found that Jeffrey Schwartz's book not only explained the theory of homeobox genes and their importance in the emergence of new species, but also described a good deal else in the field of evolution in a way that brought this intricate subject to life and was refreshingly easy to follow. I particularly recommend the first chapter, "A Rash of Discoveries", for an overview of the many finds of possibly hominid remains which constitute links with our earliest ancestors; and also enjoyed the account of the famous Piltdown hoax (pp 107 et seq.). I happen to live not far from the village of Piltdown and so have heard and read many versions of this endearingly eccentric episode of British scientific history. These others tend to centre on the "whodunnit" aspect of the case, ignoring the equally interesting scientific background: the state of evolutionary research at the time, and the possible reasons why anyone should wish to perpetrate such a hoax. Once again, the author covers both angles in a way which leaves out none of the science and makes more sense of the story.

Having read this book, I was interested to see that Jeffrey Schwartz's theory was featured in an article in the Sunday Times Magazine (September 12th, 1999), which is currently looking at important new scientific discoveries and developments to follow for the new millennium. I felt that the inclusion of the homeobox gene theory of evolution as one such was entirely justified.

In summary, I highly recommend this elegantly written book whose contents should be of great interest to anyone remotely intrigued by the evolution of species.

Contrary to what is being advertised, it is not mainly a book about a new theory of evolution. It is above all a book about the history of evolutionnary thinking, endlessly recounting its major events and disputes. Don't expect any more a synthetic introduction to what is known on homeobox genes, though the book jacket says it is central to the new theory.

A new theory of Evolution, I wanted to like this book but at its centre is a great piece of illogic. It Purports to be about homeobox (hox) genes, the controllers, and how they make sudden leaps in evolution possible. However the first 10 of 12 chapters are historical, I dont care so much for past errors, such as Darwins later Lamarkianism, I am more concerned about the best recent ideas. The historical survey seems solid, and somewhat easier than S J Goulds earlier work on Ontogeny vs Phylogeny. I was amused by the appearance of my favourite Jesuit, Teilhard de Chardin, in 1913, just in time to discover the critical tooth to establish the credibility of the Piltdown skull hoax. Chapter 11 and JS gets to his theme, hox gene as development agents. He is a bit confused about the establishment of axes - he says that the initial posterior-anterior can be established in one of two ways - on a sphere surely there are infinite possibilities. He also says the left-right axis is established in the egg - not a problem to him. But left-right parity is a problem - its something you cant communicate by a code - only chirality can communicate chirality. (Even TV signals cant communicate left-right because we cant know which way the recipients might build their TV sets) -no matter, its not central to JS's ideas. I have heard from others that the axes are not established in the oocyte, but later in the 16cell stage, I don't know for sure. JS talks about morphogens and development - people with extra fingers have longer repeat sequences of alanine in the Hoxd-13 gene , but his phrase "excess alanine.. binds to the other Hoxd genes and inactivates them for a longer period of time" seems poorly expressed. Surely the alanine repeats form some kind of protein (helix?) which binds, not as individual Amino acids. I am personally biased because my pinkies are short by 10% (everything else under the kilt is OK despite folkloric and medical? connections ) so I must have fewer alanine repeats. A second cousin has short third fingers,so I guess our clan is leading the drive towards fewer digits (early tetrapods had 7 or 8). The same Hox genes, expressed with a different timing, make for five-fold symmetrric starfish - exactly how? - seems to me we have found only the first few steps on a long trail. JS mentions another book "The shape of Life" by R Raff which might be a better read (Raff is an actual developmental biologist). (nb it was published in 1996 so misses the last few years). Homeobox genes are obviously important, but it is absurd to state that the "only molecular difference" between fruit flies and tetrapods is in "a short alanine-coding sequence" - perhaps hyperbolic phrasing, but it is important to be clear when discussing sudden evolution - there are a lot of creationist critics waiting to pounce. The major absurdity, however, is in JS's discussion of the eye. He mentions the Dawkins-Nilsson-Pelger idea that an eye can form in 400,000 generations from flat skin, with each step only slightly better than the previous. But he doesnt believe you need any selection pressure at all. He thinks the whole eye can appear in one go. Hopeful Monster indeed. (note he doesn't use the phrase "in one go" but that seems to be what the text is saying.) You can produce blank skin with no eye or socket, by knocking out one Rx gene. This is a startling result, but it is an astounding piece of illogic to assume that you can produce an eye in one step,going the other way. Surely the Rx gene is a controller of many other genes. I cant believe than an anthropology professor can make such a crude logical error the centre-piece of a book. He also seems to think that mutants will prefer to mate with each other. - "mutant homozygotes would certainly (sic) respond to each other because they would all possess the same novelty". Mate choice is what makes a species (despite Darwins title he didnt explain the origin of species) but I can assure you I dont scour the singles bar looking for short pinkies. Only my pinkies have mutated, not my mate preference - there is no connection. There's more - "feathers.. are not the result of a gradual transformation of scales. Rather, as seen in the older fossils, downlike and regular feathers are all there" well knock me down with a scale which (overnight?) turned into a feather. Gould & Eldridge might be embarrassed to have such over-enthusiasm for saltation in their tent.

Among professionals and amateurs alike, a majority of modern evolutionists firmly embrace the notion that evolution is "a change in allele frequency in a given population." Even if we included in this "change" the possibility of new alleles (a.k.a. mutations), we are still steered toward a conclusion that all alleles are equally important and necessary in development. It also tends to focus attention to those heritable traits most readily observed, since an allele is nothing more than a character state (ie blue versus brown eyes), and supports the idea that "one gene equals one trait".

Ask any professional biologist, particularly a geneticist, and they will be quick to point out that some genes (especially regulatory genes) are more important than others in development, and that "one gene equals one trait" is absurd. Yet these assumptions are deeply entrenched in the logic of basic neo-Darwinian thought. Schwartz does not present these concepts as radical new ideas, but as a neglected intellectual heritage. The source of novelty is shifted back to mutation, not selection.

This book reasserts the basics of genetics, known for a century, and challenges received wisdom about the necessary size and role of mutation (ie. what has and *hasn't* been demonstrated). If nothing else, Sudden Origins will provide the reader an opportunity to examine their assumptions about the diversity of life. Some have called the new theory contained in this book a revival of "hopeful monsters", just as some have called Stuart Kaufman's ideas the reworking of "spontaneous generation". But let us remember that throughout history intellectual heresy in one generation is often recognized as the seeds of genius in the next.

With his Sudden Origins, Jeffrey H. Schwartz can surely claim, in the current cliche, to be "reader-friendly". I am not qualified to judge his research from a professional point of view, but, as a mere interested layman, introduced to this book by a recent Sunday Times Magazine, I can vouch for its attractions to the untutored.

The rights and wrongs of Professor Schwartz's thesis only his fellow scholars can assess, but it is certainly an impressive explanation of hitherto puzzling phenomena. The author sets his own findings, reassuringly, in the historical context of evolutionary theory, relating his discoveries to Darwin and subsequent scientific investigation. For me, however, the achievement of this book lies in the manner in which the author presents his somewhat esoteric material. From the strong title and delightful dust-cover to the useful paraphernalia of end-notes, index and glossary, Professor Schwartz makes it easy for the reader to survey and manage his dense, complex and erudite content. Chapters are helpfully subdivided into headed sub-chapters and diagrams and illustrations illuminate the text. Equally welcome in a book of this kind is the author's ability to endow his material, on occasion, with unexpected warmth - see, for example, his description of the contrasting scientists, White and Clark (p15). Interestingly, when I thought that I had found something to criticise, I discovered that my criticism had been anticipated, explained and, so, invalidated in the author's Acknowledgments.

I unhesitatingly commend Sudden Origins as worthy of your five star rating.

This book gives a thorough and accurate historical summary of the development of evolutionary thought from the earliest anatomical studies to relevant studies from modern molecluar biology. In the course of doing this, the author evaluates the validity of the information in the literature and how it has been used in the past.

With this solid base, Dr. Schwartz develops an argument for the critical nature of changes in regulatory genes as the crucial driving force in evolution and uses this approach to support the theory that sudden "jumps" in the evolutionary process lead to new species rather than a gradual accumulation of small changes over long periods of time.

The hypothesis proposed by Dr. Schwartz is eminently reasonable and provides an important direction for future research. The book will be useful to both the professional student of evolution and the general reader who has an interest in this field.