Evolution in Four Dimensions, revised edition: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life (Life and Mind: Philosophical Issues in Biology and Psychology)

This is such a good book, I wish it were better. In particular, I wish that the authors had not spent so much time discussing the effects of informational and symbolic transmission on evolution (most of which is fairly obvious) and spent more time on the fascinating topics of epigentic transmission and genetic control systems, which are extremely complex and difficult issues, and go by too fast. The authors pose a question that evolutionary scholar rarely broach: If evolution produces and preserves adaptive traits, why does it not produce the trait that is the most adaptive of all -- the ability to directly transmit acquired adaptive characteristics to offspring? Ironically, despite their qualified claim that organisims do have such an ability, the authors provide an excellent Darwinian reason why this trait is so limited -- because a species which possesses it (like, say, humans) is so likely to "crash and burn" if it mistakenly adopts a trait which turns out to be maladaptive. Jablonski and her co-author are neo-Lamarkians; that is, they believe (or want to believe) in the inheritance of acquired characterists. Lamarkism is deeply distrusted by evolutionary biologists for two very good reasons: there is not much evidence for it, and a mechanism for transmitting acquired characteristics seems biochemically impossible. The authors present some good arguments why this might not be so. Particulary impressive is their discussion of epigenetics -- biochemical processess not involving genes which nonethelesss affect an organism's development. Epigenetic processes pretty clearly can be affected by environmental factors, and so environmental factors do have a direct impact on bodily devlopment, and hence evolution. More relevantly, epigentic developments can apparently be directly incorporated into the organism's germ line (the system which involves reproduction), and hence heredity, without the necessity of mutation. This issue is deep and difficult probably deserved a whole book of its own. The writing is clear and the illustrations are helpful, if a bit "cute." This book is a wonderful introduction to a problematical subject. Persons who are suspicious of classical Darwinism, but suspect that intelligent design theory is nonsense will love this book.

Jablonka and Lamb pull together many ideas about evolution to suggest that the Modern Synthesis prevalent since the 1930s is due for a reconceptualization. They argue that evolution involves not one but four kinds of inheritance systems: genetic, epigenetic, behavioral, and (in humans) symbolic. Epigenetic systems involve cellular variations appearing in the course of development, so that cells with the same DNA can develop in quite different directions. Since this information is preserved when cells divide, it can also be inherited in the reproduction of unicellular or asexually reproducing multicellular organisms. (Inheritance by sexually reproducing organisms is tricker but also possible.) Behavioral inheritance among organisms occurs through the transfer of behavior-influencing substances and through imitative and non-imitative learning. Human symbolic communication is an especially rich inheritance system, with features such as the capacity to share imagined behaviors never before tried. The genetic and non-genetic inheritance systems work together in evolution, with non-genetic changes often becoming genetically assimilated. For example, if a human population domesticates cows and starts relying on dairy products, genetic variations in the ability to digest lactose become relevant to natural selection, and so gene frequencies can change as a result of the change in customs. Jablonka and Lamb suggest that non-genetic changes often lead the way in animal evolution, with genetic changes playing catch-up. Not only is this book a far cry from the simplistic genetic determinism that characterizes many popular discussions of evolution, but it is also a departure from 20th-century Darwinian orthodoxy. While genetic changes are usually blind to outcomes, the variations that are transmitted epigenetically, behaviorally or symbolically are often more targeted, arising in responses to signals from the environment. The environment plays the dual role of inducing as well as selecting variations, and the variations are more like educated guesses about what will work than random shots in the dark. The fact that these acquired innovations can be inherited (one way or another, though not by direct modifications of genes) means that evolution is partly Lamarckian after all, at least in a broad sense of the term. Orthodox Darwinism has always been a philosophically puzzling doctrine. For a theory of change, it has placed a surprising amount of emphasis on the continuity of being, with change appearing as an accident that only occasionally happens to contribute to that continuity. For a theory of information, it has been surprisingly preoccupied with blind, completely uninformed variation. Jablonka and Lamb's understanding of evolution is both more dynamic and informationally richer. Inherited information is no longer confined to the genome, but can include information acquired and used in the course of development. Organisms participate in evolution not just as vehicles for the transmission of fixed information units (genes or their imagined cultural counterparts, memes, a notion J & L critique vigorously), but as active acquirers and interpreters of information. This is consistent with Stuart Kauffman's contention that life is even more complex and creative than biologists have realized. The book is extremely well written and documented, so that the arguments are easy to follow by readers with a limited background in biology. Highly recommended for biologists and non-biologists alike.

... in my opinion. This book is quite a treat. Jablonka and Lamb significantly advance evolutionary biology by assembling a wealth of biological knowledge. Their basic thesis is that evolution in some way acts on all forms of hereditary information carried by organisms. This is, of course, true for the information encoded on an organism's DNA, but also for information encoded in epigenetic systems, in animal behavior and in symbolic systems. The later is unique to our species. Jablonka and Lamb argue that a type of behavior which is learned by an offspring from a parent will propagate itself from generation trough generation. Successful types of behavior will over time be enriched in the population. This type of evolution will of course be ruled by different laws than genetic evolution - changes in behaviors will not be random and un-directed as DNA mutations (and even that is not certain). Thus, the "evolution of educated guesses" is taking place. Similar principles hold for epigenetic and symbolic evolution. Information is passed on, and will be enriched in the population if it increases the bearer's fitness. In addition, these levels of evolution interact. The Baldwin effect, genetic evolution directed by behavior, is one example of such an interaction. These points are made with a wealth of well-researched examples, some of them based on solidly established science, some of it on new strands of research. None of Jablonka and Lamb's ideas need you to believe anything outrageous to be true. At times they speculate about the role the mechanisms they propose could have, but the speculation seems completely reasonable to me and in many cases could serve as the starting point for interesting research projects - a real strong point of this book. What is thus presented in this book is a modernized version of evolutionary theory, taking a number of complexities into account which have previously not been assigned the importance they propably should be given. From the connection between processes at the genetic, epigenetic, behavioral and systemic levels emerges a biology where evolution is not confined to selecting for benefitial variations in DNA sequences. Rather, such genetic evolution is only at the base of a more complex evolutionary process. Dobzhansky' famous quote that "Nothing in biology makes sense except in the light of evolution" morphs into "All (hereditary information) in biology makes sense for evolution". While I am excited about Jablonka and Lamb's ideas, I found their presentation at times a bit tedious. The book could be 100 pages thinner. Especially the earlier chapters have a lot of introductory material which anyone who is picking up such a book will be familiar with. A number of times they start describing an intellectual debate about a certain topic, only to abort the description at a point when it would have been interesting, since "that would lead us too far astray". The chapters are followed by a dialog between two people defending and questioning, respectively, their ideas, which is often a bit redundant. Then, Jablonka and Lamb admittedly cover a very wide range of topics and can't be expected to be experts on all topics. But there were still some cases where they could have payed more attention. As the example for a mutagen they list LSD, which it is not, in doses consumed by humans. To confuse a piece of drug war propaganda with a scientific fact made me cringe a bit. I enjoyed the creative naivist illustrations by Anna Zeligowski which often illustrate the concepts very well. In summary: if you are a biologist who cares about a global perspective of his field, read this book. If you are one of these wonderful "educated laymen" scientists hope are abound in the public, read it as well.

This is an excellent summary of all the ways that important information is inherited by species. Specifically, evolution is not all about DNA, random variation and selection. Eva supplements the overwhelming preoccupation on Darwinian evolution and the role of DNA and genes with the related epigenetic mechanisms that control development, and more innovative behavioral and cultural mechanisms that are at work. There are three major mysteries at the heart of evolution - how can random individual mutations in DNA 'cooperate' across millennia to create complex organs like the eye? With identical DNA, how does a cell in, say the liver, know not to express genes that are needed only elsewhere, say in the heart? How do some species at some times evolve so much faster than selection and random variation would seem to permit? All the answers, well, hypotheses really are in this book. There are two other books I would recommend in combination with this one - The Plausibility of life by Kirschner; and Epigenetics by Francis Essential reading for those of us whose careers and environment have centered around the sequencing of genomes to the exclusion of all else. The small discussions at the end of each chapter at first seem a little 'hokey' but by the second chapter they become essential explorations of questions raised in the text Overall an excellent book!

As someone who did not major in biology, I was thrilled to learn about epigenetics and all the other ways that evolution can unfold compared to the usual genetic perspective.

Jablonka and Lamb have written an impressive, incisive book, with a light touch and an personal approach. They demonstrate ways (genetic, epigenetic, behavioral and symbolic) in which organisms "inherit" from their predecessors. One does not have to agree with all their positions to profit from way they consider general developmental issues. Our culture has taken a step forward through their symbolic creation---it's not the "memes" they provide, but their way of laying the basis for interacting evolutionary processes.

I bought this book as a supporting resource for my forthcoming book, The Dimensional Biologist's Toolkit (2015), and I must say I was disappointed in the lack of depth and fundamental insight. This book has a lot of details ostensibly supporting a thesis of the interaction model of genetics. To be clear, the interaction model is the theory that genes are affected by factors in the environment and the development of the organism. Considering this theme, I was disappointed to find that a lot of the information provided is fairly basic, and the rhetoric ends up coming off weak, from a strictly rhetorical point of view. I didn't enjoy this book, although I eventually found a section explaining language development, toward the end of the book, that clarified some things for me. The earlier explanations illustrated by diagrams seemed to show factors that everyone should already know, with a little chemistry mixed in. I admit, I'm approaching this book from a cosmopolitan, epistemologically-oriented direction, so my comments may come off as being unfair. It's not that no one should own this book, it is that in some ways it sets a bad example. The book has a double-horned dilemmma common to teaching about genetics, namely that students who want 'real' genetics need the hard stuff. People who want the basic stuff don't necessarily want a rhetorical message stuffed into it. From the 'hard' angle, I found this book just doesn't provide enough real information. Compounding the problem, even geneticists admit that there are some things which are unknown to genetics, so there is a real risk of not communicating anything which is absolutely real. Scientists sometimes admit that it is possible that future information will destroy the importance of 3/4ths of a theory. So one risk is the radical contingency, which doesn't work well with having a single unoriginal opinion. It has some hints of brilliant ideas, and supposedly some real interviews (which may have been constructed amongst friends exclusively for the book, in a rather artificial way), but the book's agenda is not ultimately very useful. I get the sense that this book will definitely be lost in the ensuing wave of ephemera, as new, more powerful theories, or more detailed knowledge emerge. And, as I remarked earlier, this book is not exactly state-of-the-art. So that is my long-winded way of saying, sorry, three stars. It was supposed to be a good book, but it got caught up in its message, and didn't fully deliver.

A recent biotechnology trade publication wrote that "epigenetic research surges on many fronts", and a study of textbooks in molecular biology that have been published in the last few years reveals that epigenetic mechanisms are relevant in biological systems. This book could be considered a definitive summary of what is known about epigenetic mechanisms in evolution, but also goes beyond it by arguing behavioral and "symbolic" variation also plays a significant role. Readers will get in-depth discussion of these terms and also get exposed to some speculation from the authors on how all four mechanisms, genetic, epigenetic, behavioral, and symbolic drive the evolutionary process. However the authors are careful to note the difference between speculation and facts, and this intellectual honesty is refreshing and motivates the reader to consult some of the many references given in the book. At various places in the book, readers are expected to have a solid background in molecular biology in order to follow the discussion, but non-experts in this field, such as this reviewer, can with some concentrated effort appreciate what the authors are talking about. Some of the highlights in the book include: 1. The reminder that genes are not "simple causal agents" with traits being the result of interactions among a collection of genes. Along these lines, gene regulatory networks have become a significant area of research in the last few years. 2. The point made that the Darwin theory of natural selection is a general theory of evolution, and does not make specific assumptions on the mechanisms behind heredity or variability. This assertion motivates the reader to search for different representations of Darwinian theory, this book being one of them, and further, ask the question as to how many such representations are possible, given the constraints of observation and experimentation. Are there for example, any "higher dimensional" versions of Darwinian theory (greater than 4)? 3. The discussion on information theory and its use in genetics. 4. The discussion on the ability of genomes to compensate for the lack of activity of a particular gene. This is very relevant to current methods in genetic engineering, which sometimes have their goal the "knockout" of certain genes. 5. The reminder that there is much that is unknown in molecular biology. One example given is the nature of the regulation of splicing. 6. The discussion on the advantages of sexual reproduction versus mere cloning. 7. The discussion on self-sustaining feedback loops in gene activity. This has connections with the field of mathematics called nonlinear dynamics, and a large amount of research in this field is devoted to understanding these feedback loops. 8. The view of the authors that RNA interference is a cellular immune system. This is an interesting idea, and motivates the reader to do further reading on whether it is an idea that is viable in immunology and molecular biology. 9. The discussion on "real-time" genome modification in the Sciara fly, wherein chromosomes are eliminated in both somatic and germ-line cells. The astute reader will naturally wonder how many other biological organisms are able to do this. 10. The role of methylation in transgenic strategies. This discussion is very important to those readers who want to understand the risks involved in genetic engineering. Transgene flow is considered to be a risk by some, but methylation apparently would assist in alleviating this risk. Some of the disappointments in the book include: 1. The use of thought experiments to argue some of the main points. This is not a major detraction, but this use can degenerate into philosophical speculation if one is not careful, and it seems the authors are aware of this. 2. The authors should have included more discussion on why they think the "four categories" of epigenetic inheritance are not independent. 3. The assertion made without elaboration that when humans imitate they always intend to do so. Along these lines the authors need to elaborate in more detail what they mean by a "modular system of imitative learning." Their thinking on this would be very interesting to those readers involved in the field of artificial intelligence. Indeed, the authors' assertion that "imitation is a context- and content-sensitive process, not mere copying" is very important to those who are attempting to implement cognitive processes in non-human machines. This is further exemplified in the authors' discussion on "radical" evolutionary psychology and its view that the brain is a collection of modules, each having a particular cognitive task. The authors are clearly skeptical about the existence of these modules, and it would be interesting to know whether they would find the concept of "entangled" modules, i.e. those where task sharing is the defining characteristic, useful for their conception of symbolic inheritance systems. 4. Since plants do not exhibit complex or intentional behaviors, the authors need to show why behavioral inheritance systems are not relevant, or weakly so, in the evolutionary biology of plants. This point is naturally made at the place in the book where the authors discuss the difficulties of showing the relevance of behavioral inheritance systems in animals, i.e. showing the existence of animal traditions and so on. This question can also be asked in their discussion on symbolic inheritance systems: plants do not interpret symbols or have symbolic grammars. Here again, the authors point to the absence (or purported absence) of symbolic systems in animals. Humans therefore seem to have a multi-dimensional inheritance system, and are therefore unique in this regard. 5. In their discussion of symbolic inheritance systems, the authors place too much emphasis on generative theories of grammar, and do not take into account other theories, such as cognitive grammar. How would these other theories be integrated into their thinking on the role of symbolic inheritance systems?