What do you think?
Rate this book
The Plausibility of Life: Resolving Darwin's Dilemma
Offering daring new ideas about evolution, two highly respected biologists here tackle the central, unresolved question in the field—how have living organisms on Earth developed with such astounding variety and complexity? Marc Kirschner and John Gerhart draw on cutting-edge biological and medical research to provide an original solution to this longstanding puzzle.
"In this terrific new book, molecular systems meet evolution. The result is a wealth of stimulating ideas set among clear explanations drawn from a revelatory decade in biology."—Andrew H. Knoll, author of Life on a Young Planet
"Thought-provoking and lucidly written. . . . The Plausibility of Life will help readers understand not just the plausibility of evolution, but its remarkable, inventive powers." —Sean Carroll, author of Endless Forms Most Beautiful: The New Science of Evo Devo
“Remarkably lucid and comprehensive, this new theoretical synthesis will . . . shift the grounds for debate in the controversy surrounding organic evolution.”—Booklist (starred review)
"In this terrific new book, molecular systems meet evolution. The result is a wealth of stimulating ideas set among clear explanations drawn from a revelatory decade in biology."—Andrew H. Knoll, author of Life on a Young Planet
"Thought-provoking and lucidly written. . . . The Plausibility of Life will help readers understand not just the plausibility of evolution, but its remarkable, inventive powers." —Sean Carroll, author of Endless Forms Most Beautiful: The New Science of Evo Devo
“Remarkably lucid and comprehensive, this new theoretical synthesis will . . . shift the grounds for debate in the controversy surrounding organic evolution.”—Booklist (starred review)
336 pages, Paperback
First published January 1, 2005
74 people are currently reading
639 people want to read
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 20 of 20 reviews
June 5, 2021
The majority of this book is spent explaining our growing understanding of evolution, ultimately leading up to the authors' proposal of facilitated evolution, arguing that natural selection works in tandem with something more akin to "positive selection".
The text uses popular language and is filled with small anecdotes and enough humor to keep you engaged. Though not a simple read, anyone who took college level general biology and held a curiosity about evolution (like myself) can get through this
As a whole, an engaging and fascinating read for anyone interested in the diversity of life
The text uses popular language and is filled with small anecdotes and enough humor to keep you engaged. Though not a simple read, anyone who took college level general biology and held a curiosity about evolution (like myself) can get through this
As a whole, an engaging and fascinating read for anyone interested in the diversity of life
July 30, 2014
The theory of evolution has three major elements: natural selection, heredity and variation. While support for the first two is quite solid, this book focuses on the variation part of the equation. In the classic version of evolution, it's given that random mutations cause variation, and that some small set of these mutations are helpful and therefore selected for. However, there are few things skipped over with that version of the story. First, the generation of novelty; that is, how do major jumps in evolution happen in small increments. And second, truly random mutations in a complex system like an organism would seem to have a high probability of being lethal, because if one element of the system mutates while the rest stays the same, the dependencies between elements would be broken.
This book addresses those in detail. The essence though, is that, although they are complex, organisms are not like intricate machines (a watch for example). If they were, then small changes to parts would break them. The model put forth is is similar to Legos, where organisms are made up of complete subsystems that connect rather loosely together. Mutation then works at a level of how these subsystems connect, rather than on the subsystems themselves, and mutations therefore have a much greater chance of being viable organisms - known existing parts of being connected.
If you are a software person, you'll recognized features of this biological model that we use all the time for large software systems. Keeping subsystems modular so that they don't have tight dependencies on each other, and make them external interactions between subsystems as simple and loosely coupled as possible.
The reason why questions like this can be answered is that biologists are finally getting to the point where they can answer questions about exactly how organisms and cells develop, all of which are covered here.
My biology knowledge is sketchy enough that there were parts of the book that I didn't follow very well. Although written a popular style, I'd put it a notch more technical that most books of that genre. However, the critical elements under discussion were made clear enough, and when I was able to make connections between the biology and systems thinking, this book became a major addition to my understanding of how evolution truly works.
If you are somebody whose interest in how life develops is great enough to slog your way through some hairy biology, I can highly recommend this book..
This book addresses those in detail. The essence though, is that, although they are complex, organisms are not like intricate machines (a watch for example). If they were, then small changes to parts would break them. The model put forth is is similar to Legos, where organisms are made up of complete subsystems that connect rather loosely together. Mutation then works at a level of how these subsystems connect, rather than on the subsystems themselves, and mutations therefore have a much greater chance of being viable organisms - known existing parts of being connected.
If you are a software person, you'll recognized features of this biological model that we use all the time for large software systems. Keeping subsystems modular so that they don't have tight dependencies on each other, and make them external interactions between subsystems as simple and loosely coupled as possible.
The reason why questions like this can be answered is that biologists are finally getting to the point where they can answer questions about exactly how organisms and cells develop, all of which are covered here.
My biology knowledge is sketchy enough that there were parts of the book that I didn't follow very well. Although written a popular style, I'd put it a notch more technical that most books of that genre. However, the critical elements under discussion were made clear enough, and when I was able to make connections between the biology and systems thinking, this book became a major addition to my understanding of how evolution truly works.
If you are somebody whose interest in how life develops is great enough to slog your way through some hairy biology, I can highly recommend this book..
June 19, 2007
Fascinating molecular systems view of evolution. Not really recommended for people not up on their biology jargon but pretty awesome.
September 2, 2018
Thought provoking treatise on adaptability, and origins of life's great capacity to innovate with limited material. However, despite the authors' best intentions, this book is not a easy read for non-specialists.
October 23, 2024
DOES “FACILITATED VARIATION” EXPLAIN THE ORIGINS OF NOVELTY IN EVOLUTION?
Marc W. Kirschner (born 1945) is an American cell biologist and biochemist and the founding chair of the Department of Systems Biology at Harvard Medical School. John Gerhart is a professor at UC Berkeley. [NOTE: page numbers below refer to the 314-page hardcover edition.]
They wrote in the Preface to this 2005 book, “This book is about the origins of novelty in evolution. The brain, the eye, and the hand are all anatomical forms that exquisitely serve function. They seem to reveal design. How could them have arisen? ... All are novel. And yet novelty implies the creation of something from nothing---it has always defied explanation. When Charles Darwin proposed his theory of evolution by variation and selection, explaining selection was his great achievement. He could not explain variation. This was Darwin’s dilemma... What has eluded biologists is arguably the most critical: how can small, random genetic changes be converted into complex useful innovations? This is the central question of this book.” (Pg. ix)
They continue, “In this book we propose a major new scientific theory: facilitated variation that deals with the means of producing useful variation. From an explanation of how such variation emerges comes an appreciation of the facility of evolutionary change. We present facilitated variation not only for the scientist, but also for the interested nonscientist who is ready to explore ideas at the forefront of biological theory.” (Pg. x)
They explain, “Is genetic variation purely random, or is it in fact biased to FACILITATE evolutionary change? By ‘facilitated genetic variation,’ we mean genetic variation that would be (1) biased to be viable (only nonlethal variation is heritable, the rest from the point of view of evolution is useless); (2) biased to give functional outcomes; and (3) biased to be relevant to the environmental conditions.” (Pg. 13) Later, they add, “What it evolutionary biologists were wrong to think of phenotypic variation as random and unconstrained? … we would be able to face the issue of the rate of evolution, which has always been imponderable." (Pg. 32)
They go on, “The conserved processes are fundamentally cellular processes; they operate on many levels in the development and functioning of the organism. They are the CORE PROCESSES of the organism. Central to our argument is that these processes… have very special characteristics that facilitate evolutionary change. They have been conserved, we suggest, not merely because change in them would be lethal… but because they have repeatedly facilitated changes of certain kinds around them.” (Pg. 35)
They acknowledge, “Chemistry of a biosynthetic and energy-yielding sort, and information retrieval from the genome, were achieved in this first phase of major evolutionary innovation in life… Evidence is completely lacking about what preceded this early cellular ancestor. Simpler organisms, such as viruses, are not free living; they are parasites on more complex forms and hence give no information on how the original bacteria-like organisms arose. In the hope of finding more primitive organisms that have retained ancestral characters, some biologists are actively exploring life forms that inhabit extreme environments on the Earth (hot springs, hypothermal vents). To date they have found no clue to the earlier steps of evolution.” (Pg. 50)
They suggest, “Much of the skepticism over the years about the capacity of random mutation or genetic reassortment to generate phenotypic change has arisen from the assumption that genetic changes must create very specific, multiple, complex phenotypic changes. Our view is that specificity and complexity are already built into the conserved processes, as is the propensity for regulatory coupling. It is not necessary for genetic change to create those characteristics, though they are still needed for heritable change.” (Pg. 142)
They observe, “It is the evolutionary role of exploratory processes that causes us to give them such prominence in this book. They seem be able to overcome barriers to novelty, since they generate novel structures in the course of their normal physiological function. This competency addresses the problem of evolutionary adaptations that require simultaneous events. The eye was the classic problem that defied explanation… Yet might it stretch credulity to have so many independent events, each with NO SELECTIVE VALUE, to form the first simple eye, the first wing, the first lung, or the first placenta? Might processes that generate significant variation in their routine function also reduce drastically the number of steps to achieve novelty?” (Pg. 146)
They continue, “Exploratory systems, which are broadly responsive, generate many states, any of which can be stabilized by peripheral signals. Typically, the exploratory processes are highly conserved; it is the stabilizing signals that change. When generated by the organism, these signals can be altered by genetic reassortment or mutation, which changes the selection on the exploratory system but leaves unchanged its capacity to generate multiple states. Thus by a change in the selective signal, a cell can be selected to crawl along any path, an axon can be selected to ramify in any direction. The large number of possible somatic states is easily transformed into a large number of possible phenotypes on which selection can act. This reduces the requirement that selection stabilize only very minor modifications. Substantial phenotypic variation comes out of the many somatic variations generated in the course of the normal function of the organism.” (Pg. 147-148)
Later, they add, “Exploratory mechanisms have a dual role in facilitating evolutionary change… By being globally responsive and adaptive they blunt the effects of mutation and reduce its effect and lethality. In this way they make possible the persistence of novel changes by reducing collateral damage, thus increasing the amount of heritable variation… (Pg. 176)
They summarize: “1. … phenotypic variation cannot be random because it involves modification of what already exists. 2. The existing organism constrains and deconstrains variation of its phenotype, both the kind and amount… 4. The constrained parts of the organism are the conserved core processes… Their function is to generate the phenotype from the genotype… 5. The core processes have been remarkably unchanging over time… 6. Most evolutionary change since the Cambrian has come … from regulatory changes affecting the deployment of the core processes… 8. Physiological processes that adapt the individual to environmental conditions are rich targets for evolutionary modification…
"9. We propose that a much richer source of targets is to be found in the conserved core processes of development and cell behavior, the processes directed inside the organism rather than toward the environment… 10. The core processes are built in special ways to allow them to be easily linked together in new combinations… 12. Our theory of facilitated variation… give what we think is a plausible account of the dependence of phenotypic variation on genotypic variation, indicating that novelty mostly draws on what is already present in the phenotype, and further indicating the role of conserved components and processes in evolution.” (Pg. 220-224)
They assert, “The bias introduced by facilitated variation accelerates the process of natural selection ... Thus bones, beaks, and the physiology of the heart and nervous system are modified in directions more likely to generate viable animals. This perspective moves natural selection from a theory of small changes to one that can explain the origin of significant novelty in evolution over short periods.” (Pg. 248)
They continue, “We believe that facilitated variation explains the variation side of evolvability, through the reuse of a limited set of conserved processes in new combinations and in different parts of their adaptive ranges due to genetic modulations of nonconserved regulatory components… Facilitated variation has arisen and increased by selection, we say. Since it facilitates the generation of innumerable complex, selectable, heritable traits with only a small investment of random genetic variation, it is indeed the greatest adaptation of all… we believe the organism indeed participates in its own evolution, and does so with a bias related to its long history of variation and selection.” (Pg. 252-253)
Whether one agrees 100% with the authors’ conclusions, this is an interesting, creative, and thought-provoking reconsideration of evolutionary theory. It will be of keen interest to those studying contemporary evolutionary ideas.
Marc W. Kirschner (born 1945) is an American cell biologist and biochemist and the founding chair of the Department of Systems Biology at Harvard Medical School. John Gerhart is a professor at UC Berkeley. [NOTE: page numbers below refer to the 314-page hardcover edition.]
They wrote in the Preface to this 2005 book, “This book is about the origins of novelty in evolution. The brain, the eye, and the hand are all anatomical forms that exquisitely serve function. They seem to reveal design. How could them have arisen? ... All are novel. And yet novelty implies the creation of something from nothing---it has always defied explanation. When Charles Darwin proposed his theory of evolution by variation and selection, explaining selection was his great achievement. He could not explain variation. This was Darwin’s dilemma... What has eluded biologists is arguably the most critical: how can small, random genetic changes be converted into complex useful innovations? This is the central question of this book.” (Pg. ix)
They continue, “In this book we propose a major new scientific theory: facilitated variation that deals with the means of producing useful variation. From an explanation of how such variation emerges comes an appreciation of the facility of evolutionary change. We present facilitated variation not only for the scientist, but also for the interested nonscientist who is ready to explore ideas at the forefront of biological theory.” (Pg. x)
They explain, “Is genetic variation purely random, or is it in fact biased to FACILITATE evolutionary change? By ‘facilitated genetic variation,’ we mean genetic variation that would be (1) biased to be viable (only nonlethal variation is heritable, the rest from the point of view of evolution is useless); (2) biased to give functional outcomes; and (3) biased to be relevant to the environmental conditions.” (Pg. 13) Later, they add, “What it evolutionary biologists were wrong to think of phenotypic variation as random and unconstrained? … we would be able to face the issue of the rate of evolution, which has always been imponderable." (Pg. 32)
They go on, “The conserved processes are fundamentally cellular processes; they operate on many levels in the development and functioning of the organism. They are the CORE PROCESSES of the organism. Central to our argument is that these processes… have very special characteristics that facilitate evolutionary change. They have been conserved, we suggest, not merely because change in them would be lethal… but because they have repeatedly facilitated changes of certain kinds around them.” (Pg. 35)
They acknowledge, “Chemistry of a biosynthetic and energy-yielding sort, and information retrieval from the genome, were achieved in this first phase of major evolutionary innovation in life… Evidence is completely lacking about what preceded this early cellular ancestor. Simpler organisms, such as viruses, are not free living; they are parasites on more complex forms and hence give no information on how the original bacteria-like organisms arose. In the hope of finding more primitive organisms that have retained ancestral characters, some biologists are actively exploring life forms that inhabit extreme environments on the Earth (hot springs, hypothermal vents). To date they have found no clue to the earlier steps of evolution.” (Pg. 50)
They suggest, “Much of the skepticism over the years about the capacity of random mutation or genetic reassortment to generate phenotypic change has arisen from the assumption that genetic changes must create very specific, multiple, complex phenotypic changes. Our view is that specificity and complexity are already built into the conserved processes, as is the propensity for regulatory coupling. It is not necessary for genetic change to create those characteristics, though they are still needed for heritable change.” (Pg. 142)
They observe, “It is the evolutionary role of exploratory processes that causes us to give them such prominence in this book. They seem be able to overcome barriers to novelty, since they generate novel structures in the course of their normal physiological function. This competency addresses the problem of evolutionary adaptations that require simultaneous events. The eye was the classic problem that defied explanation… Yet might it stretch credulity to have so many independent events, each with NO SELECTIVE VALUE, to form the first simple eye, the first wing, the first lung, or the first placenta? Might processes that generate significant variation in their routine function also reduce drastically the number of steps to achieve novelty?” (Pg. 146)
They continue, “Exploratory systems, which are broadly responsive, generate many states, any of which can be stabilized by peripheral signals. Typically, the exploratory processes are highly conserved; it is the stabilizing signals that change. When generated by the organism, these signals can be altered by genetic reassortment or mutation, which changes the selection on the exploratory system but leaves unchanged its capacity to generate multiple states. Thus by a change in the selective signal, a cell can be selected to crawl along any path, an axon can be selected to ramify in any direction. The large number of possible somatic states is easily transformed into a large number of possible phenotypes on which selection can act. This reduces the requirement that selection stabilize only very minor modifications. Substantial phenotypic variation comes out of the many somatic variations generated in the course of the normal function of the organism.” (Pg. 147-148)
Later, they add, “Exploratory mechanisms have a dual role in facilitating evolutionary change… By being globally responsive and adaptive they blunt the effects of mutation and reduce its effect and lethality. In this way they make possible the persistence of novel changes by reducing collateral damage, thus increasing the amount of heritable variation… (Pg. 176)
They summarize: “1. … phenotypic variation cannot be random because it involves modification of what already exists. 2. The existing organism constrains and deconstrains variation of its phenotype, both the kind and amount… 4. The constrained parts of the organism are the conserved core processes… Their function is to generate the phenotype from the genotype… 5. The core processes have been remarkably unchanging over time… 6. Most evolutionary change since the Cambrian has come … from regulatory changes affecting the deployment of the core processes… 8. Physiological processes that adapt the individual to environmental conditions are rich targets for evolutionary modification…
"9. We propose that a much richer source of targets is to be found in the conserved core processes of development and cell behavior, the processes directed inside the organism rather than toward the environment… 10. The core processes are built in special ways to allow them to be easily linked together in new combinations… 12. Our theory of facilitated variation… give what we think is a plausible account of the dependence of phenotypic variation on genotypic variation, indicating that novelty mostly draws on what is already present in the phenotype, and further indicating the role of conserved components and processes in evolution.” (Pg. 220-224)
They assert, “The bias introduced by facilitated variation accelerates the process of natural selection ... Thus bones, beaks, and the physiology of the heart and nervous system are modified in directions more likely to generate viable animals. This perspective moves natural selection from a theory of small changes to one that can explain the origin of significant novelty in evolution over short periods.” (Pg. 248)
They continue, “We believe that facilitated variation explains the variation side of evolvability, through the reuse of a limited set of conserved processes in new combinations and in different parts of their adaptive ranges due to genetic modulations of nonconserved regulatory components… Facilitated variation has arisen and increased by selection, we say. Since it facilitates the generation of innumerable complex, selectable, heritable traits with only a small investment of random genetic variation, it is indeed the greatest adaptation of all… we believe the organism indeed participates in its own evolution, and does so with a bias related to its long history of variation and selection.” (Pg. 252-253)
Whether one agrees 100% with the authors’ conclusions, this is an interesting, creative, and thought-provoking reconsideration of evolutionary theory. It will be of keen interest to those studying contemporary evolutionary ideas.
April 27, 2019
A well-organized and clear explanation of the authors' theory of facilitated variation to help show how modern findings in molecular biology and development indicate likely mechanisms of evolution. Darwin describes selection acting on naturally occurring phenotypic variation in populations of organisms. Changes were thought to occur gradually and the variation was attributed to random mutation. But how, exactly, could this lead to the development of strikingly complex physiologic and anatomic structures? Darwin's best answer, remembering that he knew nothing of genetics and almost nothing of cell biology, was that we had the advantage of eons of time. This book discusses various mechanisms only made clear in the late 20th century, e.g. weak regulatory linkage, exploratory behavior, and embryo compartmentalization, that permit evolutionary changes to occur by random changes in systems that are protected from lethality and that obviate the need for simultaneous mutations in loci scattered through the genome. It's a brilliant dissertation and will require the cleverer faith-based naysayers to fall back and reorganize.
December 25, 2018
Where does the complexity and variety as we observe in life come from? So far it seems Darwin’s random mutation and selection is not enough to give rise to the many variation.
This paper offers an important ingredient: facilitated variation. In the more complete theory of evolution, facilitated variation leads to biased mutation or a small number of genetic changes but still results in complex phenotypic novelty that adapts to environment.
How this is implemented draws sharp contrast to the design of intricate machines such as clockworks. In facilitated variations, this is thru reusing/recombining existing components and processes within their degrees of adaptability. The books discuss such mechanism on the molecular level including weak linkage and regulatory effects of allosteric proteins.
Not being well trained in biology and genetic science, I found the book a bit challenging in both technical jargon and exposition style. Nonetheless the book is highly intellectually stimulating and thought provoking.
This paper offers an important ingredient: facilitated variation. In the more complete theory of evolution, facilitated variation leads to biased mutation or a small number of genetic changes but still results in complex phenotypic novelty that adapts to environment.
How this is implemented draws sharp contrast to the design of intricate machines such as clockworks. In facilitated variations, this is thru reusing/recombining existing components and processes within their degrees of adaptability. The books discuss such mechanism on the molecular level including weak linkage and regulatory effects of allosteric proteins.
Not being well trained in biology and genetic science, I found the book a bit challenging in both technical jargon and exposition style. Nonetheless the book is highly intellectually stimulating and thought provoking.
March 24, 2023
This book took me a while to read, not because it's particularly long or very hard to read, but perhaps because it took some time to process the ideas in here. The authors lay out how several aspects of the organization of life (properties such as weak linkage and exploratory systems) endow these systems with a capacity to produce adaptive variation in the face of selective pressures. I was aware of the idea of evolvability before (e.g. from Wagner's work) but this book goes more into the organizational properties of living systems beyond the organization of the genome itself. I sometimes had the feeling that the specific properties they consider could be a subset of a broader range or perhaps manifestations of some more fundamental property, but still the book illustrates the point very well. I have the feeling that it will have an impact on my thinking about evolution.
May 21, 2022
This book taught me a lot about biology and evolution. If you already know a lot about evolution, then you might not learn that much from it, I don't know. I'm giving 4 instead of 5 stars because it talked a lot about the history of science, which I personally found boring. Overall great book.
November 22, 2024
It has several very interesting ideas, but the writing is dense and just a tiny bit more livelier than a textbook. I was only able to take a glimpse at the ideas after wading through the marsh of words.
January 5, 2021
For Grad school - interesting, yet (again) somewhat over my head
March 21, 2022
Ein wichtiges aber nicht ganz einfaches Buch.
January 29, 2023
A good review of mechanisims of evolution
March 10, 2024
Excellent
Totally immersive read on biology and facilitated variation. Amazing overview also of how organisms achieve complexity and organization. Enjoyed this one a lot.
Totally immersive read on biology and facilitated variation. Amazing overview also of how organisms achieve complexity and organization. Enjoyed this one a lot.
April 19, 2008
This is the scary part where we get to see if I actually understood what I read. To explain it a little more, they're proposing a theory called "Facilitated Variation." Basically, they're saying that it is impossible that complex structures evolved from complete small chunks of randomness because all of the complex parts couldn't possibly be coordinated just by chance (e.g. the muscles, bones, capillaries, nerves, etc. of the hand), and also because the individual bits of things have no adaptive value and so wouldn't be selected for. "Facilitated Variation" involves the interplay of the environment and the organism (like Darwin said), core processes, and creating certain constraints. All of this stuff makes the organism more able to tolerate change, and makes it less likely that the change will be lethal. So as an example, if an insect develops an extra set of wings, it may still survive because it's only one tiny part of the body that is affected.
Right then. So genetic mutation in itself is random, but the variation that gets passed on is sort of...not. Okay. So onto my thoughts.
This is an important book, because this really might change the way we learn about the mechanism for variation in schools. It's amazing how fast this new information comes out really and this isn't the first time that something I've learned has been put out of date. Of course, this is a fledgling theory, but definitely an intuitive one. Some parts of the book were kind of arrogant though. Really, it's complementing Modern Synthesis and explaining the mechanics more than anything else, so I see it as more of a synthesis than a theory.
Despite the long length of time it took me to get through it, this is a very readable book written in very clear language (with cool pictures!). The sheer volume of information makes it a challenge (and I've taken 2 evolution courses so a lot of it was stuff I already knew). Be prepared to exert a lot of brain-power (or at least, dig up those old high school biology notes).
Right then. So genetic mutation in itself is random, but the variation that gets passed on is sort of...not. Okay. So onto my thoughts.
This is an important book, because this really might change the way we learn about the mechanism for variation in schools. It's amazing how fast this new information comes out really and this isn't the first time that something I've learned has been put out of date. Of course, this is a fledgling theory, but definitely an intuitive one. Some parts of the book were kind of arrogant though. Really, it's complementing Modern Synthesis and explaining the mechanics more than anything else, so I see it as more of a synthesis than a theory.
Despite the long length of time it took me to get through it, this is a very readable book written in very clear language (with cool pictures!). The sheer volume of information makes it a challenge (and I've taken 2 evolution courses so a lot of it was stuff I already knew). Be prepared to exert a lot of brain-power (or at least, dig up those old high school biology notes).
September 2, 2023
Just how genotypic variation leads to phenotypic variation through the contraints of a few thousand gene products that are used in varying configurations is a surprisingly underappreciated, yet critical, component of evolutionary theory. Random mutations do not simply cause random changes in the phenotype, but are channeled through the contraints of developmental biology. The book presents the basic idea scholarly, and maybe just a wee bit pompously as a 'new theory'. The presentation of both the historical backdrop as well as the evidence for reduced degrees of freedom in phenotypic variation based on more or less conserved gene products are outstanding. However, a discussion of information theory is entirely missing - the role of genomic 'unfolding' of information in constraining the phenotype. Similarly missing: the role of self-organization in facilitating evolution to not just be a random tinkerer. Evolution is not just facilitated by the existence of 'core processes'. Albeit asking the same larger question, the authors make no reference of Stuart Kauffman's decades of work on the evolution of life. The project 'Plausibility of Life' ulitmately remains much narrower than the title insinuates.
December 25, 2010
Darwin's theory of evolution explains the process of natural selection, but doesn't explain the sources of variation the selection acts upon. A lot more is known about variation now than in Darwin's days: how Hox genes divide the bilateral animal embryo into segments, and allow mutated genes to change the development of one segment only; what parts of the genome are conserved for all life, what parts are for all eukaryotes, and so on, and what parts are plastic. There is a connection between the plasticity of the phenotype and that of the genotype; if an organism's phenotype is sufficiently plastic, the organism can colonize an unfamiliar environment but be stressed in it, as it is better adapted to the original environment; if the genotype is sufficiently plastic, later one of its descendants may have a mutation that makes it less stressed and better adapted; with time this descendant's descendants will predominate.
August 14, 2011
This is a fascinating book that proposes a new neo-Darwinian theory for the evolution of life. The theory is called "facilitated variation", because the authors believe that purely random mutations are not sufficient to produce the variability upon which selection can act. The authors show how the biases in phenotype variation play a large part in evolution.
This may be a very important book, but to tell the truth, I don't understand much of it. The book is highly technical, but it is cast as a guide for the knowledgeable layman, not a graduate-level textbook. So, I cannot recommend this book to the average person interested in the subject, but only to someone who has a very strong background in molecular biology, embryology, or evolution.
This may be a very important book, but to tell the truth, I don't understand much of it. The book is highly technical, but it is cast as a guide for the knowledgeable layman, not a graduate-level textbook. So, I cannot recommend this book to the average person interested in the subject, but only to someone who has a very strong background in molecular biology, embryology, or evolution.
February 26, 2016
Very very interesting book on the modularity of biology, and its implications for biology's ability to adapt to its surroundings. I don't agree on all the conclusions of the authors, but I fully agree with their statement that (quoting from memory), "the question of origin of novelty remains one of the biggest challenges in biology today".
November 29, 2015
A great book if you are interested in how evolution creates very complex system known as life.
Displaying 1 - 20 of 20 reviews