(posted on my blog: davenichols.net)

Sean Carroll, researcher and professor at the Howard Hughes Institute, is a genetics expert who offers a wonderful exploration of the cutting-edge science of evolutionary development (evo devo). This book, drawing from decades of genetics research as well as experiments performed in Carroll's own lab, reveals the subtle and exquisite results of millions of years of evolution as it relates to (specifically) embryology.
The first hundred pages or so are a primer on evolution as it is theorized in the Modern Synthesis of evolution. We find that the evidence for evolution is not just substantial, but largely consistent with this theory and overwhelmingly evidence of its predictions.

The second part of the book serve to isolate a few choice types of evidence, including fossil records and genes, and presents the findings of evolutionary development researchers as they apply to the making and diversity of animal species. Carroll focuses on numerous examples in nature of evolutionary processes, including the diversity and differences of butterfly patterns, three different wing development processes, and the coloration changes which lead to black pigmentation.

Carroll wraps up the latter half of the book by challenging the notion that creationism can explain any of this, and instead, offers that the proof of evolution was undeniable decades ago, and only strengthened with more recent research. Humans share a staggering portion of our genes, including the nearly-universal tool kit genes which dictate timing and location of other genes. Human beings are shown to be part of this earth-wide process, not a seperate entity with unusual properties.

At times, Endless Forms is a bit clinical, with several dozen pages running together filled with technical terms and often difficult-to-understand processes. I did have to reread sections to fully understand what was being stated. While this made it slow going at times, the result for me (and I hope for other readers) was a detailed understanding of why evo devo research can answer difficult questions about evolutionary processes which are unanswered in other disciplines.

For anyone interested in the clinical side of evolutionary research, this book is an excellent intermediate-level study of evo devo. Carroll is a fascinating researcher with years of first-hand experience in the field. While the text is dry at times, the information provided is worth the time spent to understand it. Four stars. ( )

This book is quite clear and readable. It sometimes overreaches in its claims, and starts out very slowly. Instead of the high-school level exposition of genetics, it would have been more useful to talk about modern experimental setups. The book is almost entirely missing any discussion about how the research is done. This important missing aspect is the main flaw. However, the conclusions are presented well, with many examples from different species.

There are few very nice ideas that it explains well. For example,
* The same tool kit proteins are used to guide development across all sorts of animals, and portions of it predate the Cambrian explosion. Changes in control switches and "circuits" (combinations of switches) in the DNA modify how these proteins are used. There is strong pressure to leave the homeotic (Hox) genes the same, though.
* Complexity in form is often enabled by duplication of modular structures, followed by specialization. (A perfect example are the many specialized structures in arthropods.) For this reason, the same tool kit proteins to place many structures that now seem quite different. One can guess that without modular structures, allowing for this kind of evolution, animals could not have been so successful. ( )

A great introduction and review of the work linking the developmental impact of reusing the master regulatory proteins to control a changing galaxy of specific proteins to alter the final organisms form to fit its habitat.
He details the emergence of the body axes under the Hox proteins and how they work to isolate the expression of genes to promote modularity. Isolation makes regional use of bone, collagen, epithelium etc independent of other modules that also use the same genes. This allows constant tinkering without pleiotropic disruption.
The final result is:
1 Hox mapping regulation proteins. Body axis planers.
2 Master body specializing regulators. Eye, limb bud, heart. Look up Pax6, Dll, Tinman for examples of DNA binding regulatory proteins.
3 Regulators at the cell level to keep the life process going. Cellular housekeeping genes

1 - reuse what is already there – modify preexisting systems.
2 – multifunctionality & redundancy. If the systems do overlapping jobs there is space to separate and specialize. Division of labor => niche adaptation
3 – modularity to allow modification of isolated regions independent of other modules that also use the same genes.

Modular architecture - Isolate the control to the geographic position.
Master genes for mapping and local master organizers- expressed homeobox proteins
The physical geography
Complex DNA regulatory patterns to provide regulatory combinations of switch settings. Allows reuse in time and specify cell type expression.

This one combines well with "Your Inner Fish" ( )

An excellent and clear introduction to the science of evo-devo.

Caroll lays out beautifully what he and colleagues are learning through combining embryology with evolution, and shows how the union solves a number of mysteries that have been puzzling scientists for decades.

Although this is very definitely a layman's introduction, it does get quite deep into the science, to the point that I found myself a bit confused by all the different concepts - switches, toolkits, etc.

I also couldn't help feeling that he allows his enthusiasm - and his bias as one of the leaders in the field - to get the better of him, leaving the impression that not only is evo-devo the best thing since sliced bread, but that no-one had ever made any progress in studying evolution until it came along.

Pity, because the science clearly has had a major impact, but there's still plenty of interesting things going on outside of the field and Carroll doesn't do himself any favours by implying otherwise.

This book took me an age to read, I got weighed down in the detail, which is numerous and complex. Not a book for those with no prior reading on the subject. I'm no biologist and no scientist of any kind, but I am well read on evolution. This undoubtably helped me understand the complex issues surrounding Evo-Devo (Evolutionary Developmental Biology) . There has been a real wealth of study in this area in the last 25 years and Carroll succiently presents this is a series of well laid out chapters.

He starts with "Animal Architecture and moves through butterflies to the geneticists favourite animal, the fruit fly (Drosophilia), he follows this with a good chapter on mutation, touching on a lot of areas that Leroi covered in the book I read earlier in the month. He then moves on to the making of human offspring and the working of the genome. This is where I got bogged down as you really do need a good grasp of genetics for this section.

Part II was where the book really took off with a study of fossils and the makings of animal diversity, and the making of man. The main point of the book is the basic plan of animal development has been around for millions of years and that the evolution of new forms is not down to new gene development but the using of old genes in new ways.

This was my first reading of Evo-Devo but it certainly won't be my last. ( )