Extending evolutionary theory? - James Shapiro

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for James Shapiro's talk on Biological action in Read-Write genome evolution.

Many of the most important evolutionary variations that generated phenotypic adaptations and originated novel taxa resulted from complex cellular activities affecting genome content and expression. These activities included: (i) the symbiogenetic cell merger that produced the mitochondrion-bearing ancestor of all extant eukaryotes; (ii) symbiogenetic cell mergers that produced chloroplast-bearing ancestors of photosynthetic eukaryotes; and (iii) interspecific hybridisations and genome doublings that have generated adaptive radiations and new species of higher plants and animals. Adaptive variations have also arisen by horizontal DNA transfers (frequently involving infectious agents), by natural genetic engineering of coding sequence DNA in protein evolution (e.g. exon shuffling), and by mobile DNA rewiring of transcriptional regulatory networks, such as those essential to viviparous reproduction in mammals. In the most highly evolved multicellular organisms, we now know that biological complexity scales with ‘non-coding’ DNA content rather than with protein-coding capacity in the genome. Coincidentally, we have come to recognise that ‘non-coding’ RNAs rich in repetitive mobile DNA sequences function as key regulators of complex adaptive phenotypes, such as stem cell pluripotency. The intersections of cell activities and Read-Write genome modifications provide a rich molecular and biological foundation for understanding how ecological disruptions can stimulate productive, often abrupt, evolutionary transformations.

I have dozens of questions for Jim Shapiro but here are two possibilities.

Most of the events you describe are one-off events in the history of life. They are mostly accidents. They were unpredictable. How does the occurrence of unique events such as endosymbiosis or genome doubling fit into evolutionary theory as opposed to just historical facts in the history of life.

OR

Michael Lynch and others say that the amount of junk DNA in a genome correlates with the population size of the species. This view is perfectly consistent with modern population genetics. There is plenty of evidence that 90% of our genome is junk. You seem to be implying that this extra DNA is not junk but serves some adaptive purpose. What evidence do you have that supports this claim and why do you disagree with Michael Lynch?

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Extending evolutionary theory? - Kevin Laland

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for Kevin Laland's talk on The middle ground between artificial and natural selection: niche construction as developmental bias.

Organisms modify and choose components of their local environments. This ‘niche construction’ is subject to extensive research across several academic fields. It is well appreciated that niche construction can alter ecological processes, modify natural selection, and contribute to inheritance through ecological legacies. However, niche construction is not usually regarded as an evolutionary process, probably because traditional evolutionary accounts restrict evolutionary processes to phenomena that directly change gene frequencies (e.g. selection, mutation, drift).

Alternative perspectives can be of value if they generate novel predictions, open up new lines of enquiry, or generate new insights. The niche-construction perspective within evolutionary biology provides an alternative account of the causal relations underlying adaptation, a stance that has already led to a number of valuable insights. Here I suggest that there is heuristic value in regarding niche construction as an evolutionary process, on the grounds that it initiates and modifies the selection acting back on the constructor (and other species) in an orderly and directional manner. As a consequence, niche construction co-directs adaptive evolution by imposing a statistical bias on selection (an externally expressed form of developmental bias).

I illustrate how niche construction can generate developmental bias by comparing it with artificial selection, where I suggest it occupies the middle ground between artificial and natural selection. This perspective has heuristic value for the evolutionary biologist, leading to testable predictions related to: (i) trait evolution, including the evolution of sequences of traits and parallel evolution; (ii) responses to natural selection in the wild; and (iii) biodiversity.

I don't get this emphasis on niche construction. Biologists have been talking about how organisms modify the environment for one hundred years or more. I can see how an understanding of particular examples, such as the increase in oxygen levels due to the evolution of water splitting reactions, can provide insight into the history of life but how does that fit into evolutionary theory?

I don't have any questions for Kevin Laland. I'm anxious to see how the people at this meeting view niche construction.

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Extending evolutionary theory? - Paul Brakefield

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for Paul Brakefield's talk on Does the way in which development works bias the paths taken by evolution?

Developmental bias was defined in a seminal review some thirty years ago that resulted from an early ‘meeting of minds’ of developmental and evolutionary biologists driven by John Maynard Smith and Lewis Wolpert. Although there has been dramatic progress since then in revealing in exquisite detail how morphologies develop, there are few well-worked case studies of potential developmental bias, as well as little understanding of how important the process has been in shaping the evolution of animal form. Therefore, it is timely to think about what is needed to facilitate the analysis of the extent to which patterns of evolutionary diversification are biased by how development works, and indeed whether it is useful to distinguish this process from that of genetic channeling.

Here are two possible questions for Paul Brakefield ...

Stephen Jay Gould published Ontology and Phylogeny in 1977. He wrote extensively about developmental constraints until his death in 2002. Richard Dawkins also wrote about developmental constraints, most notably in his discussion of whether pigs could fly in The Blind Watchmaker. How do your views differ from those that have been around for decades and why do you think it requires a modification of evolutionary theory today?

OR

In The Structure of Evolutionary Theory, Gould wrote 270 pages on developmental constraints emphasizing their POSITIVE role in evolution as opposed to just their negative effects on limiting natural selection. He said,

The concept of constraint must include theoretically legitimate and factually important positive meanings—i.e., constraints as directing causes of particular evolutionary changes—rather than only the negative connotations of structural limitations that prevent natural selection from crafting an alteration that would otherwise be favored and achieved.

How do your views differ from what Gould wrote about so extensively in 2001?

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Extending evolutionary theory? John Dupré

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for John Dupré's talk on The ontology of evolutionary process.

Ontology is the branch of philosophy that considers in the most general way the nature of reality. An ancient and fundamental ontological question is whether reality is ultimately composed of stable things or is everywhere processual, in flux. A number of distinguished 20th century biologists, including, for instance Conrad Waddington, Joseph Needham, and Ludwig von Bertalanffy, thought it important to stress the fundamentally dynamic, processual character of living systems. While evolution is of course a process, it is often implicitly supposed that the entities that evolve or that constitute the evolutionary process, whether genes, organisms, populations, or whatever, are kinds of things. Following the authors mentioned above, I argue that these too are better seen as processes, albeit highly stabilised processes.

In this talk I shall argue that a process ontology is correct and that it has important implications for how we should think about evolution. First, with regard to the constituents of the evolutionary process, process ontology highlights the limitations of atemporal descriptions of organisms, for example in terms of gene sequence, and of populations as atemporal abstractions from evolving lineages. Second, whereas in an ontology of things the primary explanatory task is that of understanding change, in a world of process it is of equal or even greater importance to explain stability. The first step in articulating a fully processual view of evolution is to describe the processes that sustain persisting lineages. Doing so should provide fresh perspectives on the processes that can produce changes in lineages.

John Dupré is a philosopher. He talks like a philosopher. I don't understand what he's talking about and, quite frankly, I don't care. No questions for him.

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Extending evolutionary theory? - Tobias Uller

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for Tobias Uller's talk on Heredity and evolutionary theory.

Heredity is a central concept in biology and one of the core principles needed for evolution by natural selection. For most of the past century inheritance has been conceptualised and defined in terms of transmission of genes. Emerging developmental perspectives on evolution appear to challenge this perspective in several ways. Here I will explain how evolutionary biologists treat heredity conceptually and mathematically. These perspectives are heuristically useful but they impose a certain structure on evolutionary theory and leave out aspects of heredity that may be important to understand evolution. An alternative representation understands heredity as an outcome of developmental processes. I will suggest that this perspective helps to clarify how different mechanisms of inheritance contributes to evolution.

I have to wait to hear this talk in order to figure out what he means. From reading the abstracts to some of his papers I think he's going to promote plasticity and epigenetics ... or maybe maternal effects.

In any case, the standard understanding of "heredity" is when alleles (genes) are passed from one generation to another. The process usually involves DNA replication and cell division but it encompasses horizontal transmission. I'll be interested in hearing about other mechanisms of heredity.

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Extending evolutionary theory? - Russell Lande

I will be attending the Royal Society Meeting on New trends in evolutionary biology: biological, philosophical and social science perspectives. I'll post each of the abstracts and ask for your help in deciding what question to pose to the speakers. Here's the abstract for Russell Lande's talk on Evolution of phenotypic plasticity.

The scope and relative rates of adaptive phenotypic change from plasticity versus standard Darwinian evolution adaptive genetic changes depend on the time scale and the range of phenotypic alteration being considered. This distinction becomes blurred when plasticity itself evolves. Using standard methods from neo-Darwinian population genetic theory, I review recent models on the evolution of phenotypic plasticity in changing environments, emphasising the roles of environmental predictability and costs of plasticity in constant and labile characters. Adaptation to a novel environment may often occur by rapid evolution of increased plasticity followed by slow genetic assimilation of the new phenotype. I elucidate the connection between environmental tolerance and plasticity. The theory of evolution of phenotypic plasticity is an important extension to neo-Darwinism, but does not necessitate a major revision of its foundations. The same conclusion applies to epigenetic mechanisms including interactions between genes or tissues in development, and to transgenerational phenotypic effects such as somatic inheritance, maternal effects and DNA methylation.

I could ask this question ...

Imagine a small group of organisms that find themselves in a new environment. Let's assume they have a genome containing 10,000 genes. How do they select for increased phenotypic plasticity in order to better adapt to the new environment? Are all genes affected or just a small number that might increase fitness? Which genes acquire additional potentially beneficial alleles that were not present in the small population before it encountered the new environment and how does that mechanism work?

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What is "THE" theory of evolution?

I wish people would stop referring to "THE" Theory of Evolution. What they really mean, of course, is "The Theory of Natural Selection"—part of modern evolutionary theory. There's no question about the importance of natural selection and the major contribution of Charles Darwin in discovering it and promoting it to the general public. However, in 2016 there's a lot more to evolutionary theory than just natural selection and the public needs to know this. Many scientists need to know this.

There's also no debate about Darwin's contribution to promoting the evidence of evolution and descent with modification. He made a brilliant case for evolution in his books. Subsequent discoveries have demonstrated beyond a reasonable doubt that modern life is the product of billions of years of evolution. Descent with modification is a scientific fact. The fact that evolution has occurred is not a theory. It is not a "theory" that humans and the other apes have descended form a common ancestor ... it is a fact [Evolution Is a Fact and a Theory].

We perpetuate confusion in the minds of the general public if we don't make it abundantly clear that modern evolution theory is not about whether evolution occurred and it's not just about natural selection.

I was prompted to write this blog post by a recent article in New Scientist: Darwin’s discovery: The remarkable history of evolution.¹ The author is John van Wyhe of the National University of Singapore. He is a historian of science with a special interest in Charles Darwin and Alfred Russel Wallace.

The article contains a box that says ...

Evolution in a nutshell

Darwin’s and Wallace’s theory of evolution maintains that new species are descended from earlier ones. This long-term process happens because all organisms vary. The tiny variations are naturally “selected” by virtue of whether or not they help an organism to survive the brutal struggle for existence in nature. Many are born, but few survive; fortuitous variations are preferentially passed on. This process of endless filtering works to adapt organisms to their environment.

This is misleading in two ways. First, it states that common descent is part of the the theory of evolution. Second, it only talks about natural selection as a mechanism of evolution.

We wish to question a deeply engrained habit of thinking among students of evolution. We call it the adaptationist programme, or the Panglossian paradigm.

S.J. Gould & R.C. Lewontin (1979) p. 584Fortunately, the main body of the article is quite a bit better. Here's what John van Wyhe actually says about evolution.

Despite its baptism of fire, On the Origin of Species almost single-handedly convinced the international scientific community that evolution was a fact. In his 1889 book Darwinism, Wallace wrote of the revolution Darwin effected: "this totally unprecedented change in public opinion has been the result of the work of one man, and was brought about in the short space of twenty years!"

The theory of evolution has come a long way since. Today we think of it in terms of genes and DNA, but Darwin and Wallace had no idea of their existence. It was only in the 1930s and 1940s that genetics was incorporated into evolutionary theory. Even now, new discoveries are shaking up our understanding, but at the core of the modern theory remains Darwin’s idea of descent with modification.

Today evolution has many critics outside the scientific community, especially in the US, where a significant percentage of the population are creationists. What is forgotten is that the scientific debate over evolution was over by the 1870s and has never again been a matter of serious dispute.

Darwin showed that evolution is a fact and it's good that van Wyhe made this point in a article aimed at the general public. It's not good when he says "the core of the modern theory remains Darwin’s idea of descent with modification."

It's not good that he still refers to "THE" theory of evolution instead of "evolutionary theory," which encompasses all kinds of things other than natural selection.

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1. The title in the print edition is: "The Evolution Revolution."

Evolution according to "New Scientist"

A recent editorial in the magazine New Scientist caught my eye. The title is "Long Live Evolution" and it offers support for "new ideas" about evolution. The online version is titled Darwin’s beautiful theory must itself be allowed to evolve. The author is not identified; I assume it's one of the editors.

Here's the opening paragraph ...
Nothing in evolution makes sense except in the light of population genetics.

Michael Lynch (2007)

Darwin's great theory must itself be allowed to evolve

THE theory of evolution is a splendid thing: an elegant and utterly logical explanation for how natural selection solves the problems of survival and creates the enormous diversity of life we see in the world around us.

There is no such thing as "THE" theory of evolution. Evolutionary theory is complex. It covers several mechanisms (natural selection, random genetic drift) and its core is population genetics—something that was unknown in Darwin's time.

We know that Darwin’s hypothesis of natural selection ... was correct, but we also know that there are more causes of evolution than Darwin realized ...

Douglas Futuyma (2009)
The New Scientists editor is describing the theory of natural selection but he/she even gets that wrong because most of life's diversity is probably NOT due to natural selection.

The irony here is that New Scientist then goes on to say ...

That brings to the fore areas that are not part of the canon of evolutionary theory: epigenetics, for example, which studies how organisms are affected by changes in the ways in which genes are expressed, rather than in the genes themselves.

Attempts to incorporate such elements into evolutionary theory have not always been welcomed, however. That is understandable, given how successful the theory has been without them. Occam’s razor applies: do not add complications unless they are absolutely necessary.

But another motivating factor is undoubtedly the fear that if scientists themselves are seen to suggest that even small details of the theory of evolution could be improved upon, its detractors will seize upon them with avidity. This is a well-founded fear: it happens all the time, with well-funded and highly visible front organisations distorting scientific discussion to create the false impression of disagreement about the basics of evolutionary theory.

It is a fear scientists need to overcome, lest the admirable defence of truth mutates into defensiveness and rigidity. It is one thing to counter reactionaries who reject evolution; it is quite another to be dismissive of or even hostile to scientists who have new ideas to offer.

I recommend that the editors of New Scientist purchase and read any introductory textbook on evolution before they write any more silly editorials. They will learn that "Darwin's great theory" has already been changed beyond anything that Darwin would have recognized. The fact that the editors of a prominent science magazine don't understand evolution is an example of one of the main problems that have led to so much confusion today over recent attempts to extend evolutionary theory.

If science journalists are going to write about whether epigenetics should be part of evolutionary theory then they better do their homework before criticizing prominent evolutionary biologists for being afraid of changing even "small details" of modern evolutionary theory. I suggest they start by reviewing some "small details" like Neutral Theory, random genetic drift, hierarchical theory, species selection, punctuated equilibria, sympatric speciation, group selection, directed mutation, cladistics, kin selection, selfish genes, endosymbiosis, and a host of other aspects of evolution that have been vigorously debated in the scientific literature over the past century.

Maybe after doing their homework they will realize that prominent evolutionary biologists who question epigenetics are not doing it because they fear change ... they're doing it because "epigenetics" has been debated for fifty years and it has little to do with modern evolutionary theory. Maybe the science journalists will realize that proponents of the "extended evolutionary synthesis" are as ignorant of modern evolutionary theory as they were before they did their homework.

The editorial ends with ...

Evolution is true. But it is also a living, breathing idea that must not be allowed to ossify into a dogma of the kind that it has done so much to sweep away.

Ironically, the most common "dogma" is the false idea that evolutionary theory hasn't changed since Darwin's time and the editor of New Scientist is a prime example of this kind of ossification.

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Proponents of the Extended Evolutionary Synthesis (EES) explain their logic using the Central Dogma as an example

There's a group of biologists who think that the current version of evolutionary theory is insufficient. They want to create an extended evolutionary synthesis that incorporates evo-devo, plasticity, niche construction, evolvability, epigenetics, and other things.

You might be wondering how these things could be incorporated and what that would do to "classic" evolutionary theory. Fortunately, we have a road map provided by Massimo Pigliucci and Gerd Müller in chapter one of Evolution: The Extened Synthesis. They help us out by providing an analogy.

As we will see in the rest of this volume, several of these tenets [of the Modern Synthesis] are being challenged as either inaccurate or incomplete. It is important, however, to understand the kind of challenge being posed here, in order to avoid wasting time on unproductive discussions that missed the point of an extended evolutionary synthesis. Perhaps a parallel with another branch of biology will be helpful. After Watson and Crick discovered the double-helix structure of DNA, and the molecular revolution got started in earnest, one of the first principles to emerge from the new discipline was the unfortunately named "central dogma" of molecular biology. The dogma (a word that arguably should never be used in science) stated that the flow of information in biological systems is always one way, from DNA to RNA to proteins. Later on, however, it was discovered that the DNA > RNA flow can be reversed by the appropriately named process of reverse transcription, which takes place in a variety of organisms, including some viruses and eukaryotes (through retrotransposons). Moreover, we now know that some viruses replicate their RNA directly by means of RNA dependent RNA polymerases, enzymes also found in eukaryotes, where they mediate RNA silencing. Prions have shown us how some proteins can catalyze conformational changes in similar proteins, a phenomenon that is not a case of replication, but certainly qualifies as information transfer. Finally, we also have examples of direct DNA translation to protein in cell-free experimental systems in the presence of ribosomes but not of mRNA. All of these molecular processes clearly demolish the alleged central dogma, and yet do not call for the rejection of any of the empirical discoveries or conceptual advances made in molecular biology since the 1950s. Similarly, we argue, individual tenets of the Modern Synthesis can be modified, or even rejected, without generating a fundamental crisis in the structure of evolutionary theory—just as the Modern Synthesis itself improved upon but did not cause rejection of either Darwinism or neo-Darwinism.

I thank Pigliucci and Müller for giving us a clear idea of the logic behind their attack on the Modern Synthesis.

... I must correct a wrong idea that has been spreading for the past three or four years. It was discovered some years ago that in some cases, the transcription step from DNA to RNA works in the reverse direction. That is nothing surprising. ... it could be predicted that such events could occur. They do occur, indeed, but this must not be taken to mean that information from protein could possibly go back to the genome. ... I am ready to take any bet you like that this is never going to turn out to be the case.

Jacques Monod (1974) p.394The original, and correct, version of the Central Dogma of Molecular Biology was stated clearly by Francis Crick in 1958. Crick restated the Central Dogma of Molecular Biology in a famous paper published in 1970 at a time when the premature slaying of the Central Dogma by reverse transcriptase was being announced (Crick, 1970). According to Crick, the correct, concise version of the Central Dogma is ...

... once (sequential) information has passed into protein it cannot get out again (F.H.C. Crick, 1958)

The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred from protein to either protein or nucleic acid. (F.H.C. Crick, 1970)

Jim Watson published the well-known, but incorrect, version in his 1960s textbook but anyone who does even a little bit of research will discover that the Crick version is the original [see: The Central Dogma of Molecular Biology].

Here's the summary provided by Francis Crick in his 1970 Nature paper.

Fig. 1. Information flow and the sequence hypothesis. These diagrams of potential information flow were used by Crick (1958) to illustrate all possible transfers of information (left) and those that are permitted (right). The sequence hypothesis refers to the idea that information encoded in the sequence of nucleotides specifies the sequence of amino acids in the protein.

This is important because whenever someone attacks the Central Dogma you can get a good idea of their academic ability by seeing if they understand the concept they attack. In this case, there's a question about proponents of the extended evolutionary synthesis and whether they have a sufficient grasp of evolutionary theory to be challenging it. Pigliucci and Müller have tried to convince us that they know what they are talking about by giving us an analogy; namely, the "demolition" of the Central Dogma of Molecular Biology.

They didn't do their homework. That doesn't inspire confidence in their ability to overthrow modern evolutionary theory.

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Crick, F.H.C. (1958) On protein synthesis. Symp. Soc. Exp. Biol. XII:138-163. [PDF]
Crick, F. (1970) Central Dogma of Molecular Biology. Nature 227, 561-563. [PDF file]
Monod, J. (1974) "On the Molecular Theory of Evolution" reprinted in Mark Ridley (editor) Evolution (1997) p. 389

Darwin's statue

A large statue of Charles Darwin was installed in the main foyer of the London's Natural History Museum in 1885—just a few years after Darwin's death. It was removed in 1927 and replaced by a statue of Richard Owen who was no fan of Darwin.

The museum came to its senses in 2009 and put the statue back in it's original position. (It had been in the cafeteria in the basement.) Read the story at: Moving Darwin.

Owen was the man who founded the museum and he was also known for his support of structuralism—the idea that basic body plans cannot be easily explained by evolution. Structuralism is the new buzzword among Intelligent Design Creationists. They don't understand the concept but they're certain it refutes evolution and supports goddidit.

Michael Denton is upset about the statue [see Conversations with Michael Denton: You Can Move the Statue if You Wish...]. Watch the video ...

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A "synthetic" view of the Modern Synthesis

I just re-read a 1997 paper by Francis Ayala and Walter Fitch (Ayala and Fitch, 1997). The opening two paragraphs describe the Modern Synthesis of Evolution in a very interesting way. The emphasis is on the history and the contributions of Theodosius Dobzhansky (1900-1975) but it makes another point that I'd like to mention.

Theodosius Dobzhansky (1900–1975) was a key author of the Synthetic Theory of Evolution, also known as the Modern Synthesis of Evolutionary Theory, which embodies a complex array of biological knowledge centered around Darwin’s theory of evolution by natural selection couched in genetic terms. The epithet ‘‘synthetic’’ primarily alludes to the artful combination of Darwin’s natural selection with Mendelian genetics, but also to the incorporation of relevant knowledge from biological disciplines. In the 1920s and 1930s several theorists had developed mathematical accounts of natural selection as a genetic process. Dobzhansky’s Genetics and the Origin of Species, published in 1937 (1), refashioned their formulations in language that biologists could understand, dressed the equations with natural history and experimental population genetics, and extended the synthesis to speciation and other cardinal problems omitted by the mathematicians.

The current Synthetic Theory has grown around that original synthesis. It is not just one single hypothesis (or theory) with its corroborating evidence, but a multidisciplinary body of knowledge bearing on biological evolution, an amalgam of well-established theories and working hypotheses, together with the observations and experiments that support accepted hypotheses (and falsify rejected ones), which jointly seek to explain the evolutionary process and its outcomes. These hypotheses, observations, and experiments often originate in disciplines such as genetics, embryology, zoology, botany, paleontology, and molecular biology. Currently, the ‘‘synthetic’’ epithet is often omitted and the compilation of relevant knowledge is simply known as the Theory of Evolution. This is still expanding, just like one of those ‘‘holding’’ business corporations that have grown around an original enterprise, but continue incorporating new profitable enterprises and discarding unprofitable ones.

The important point here is that evolutionary theory is a complex synthesis of sub-theories, hypotheses, and observations. While it may be convenient to refer to this synthetic version as the "Theory of Evolution," it's also very misleading.

I strongly recommend that we abandon that term and use "evolutionary theory" instead. Furthermore, we should be careful about using the term "Modern Synthesis" unless we are specifically referring to the version of evolutionary theory that was popular in the 1950s.

It's true that Ayala and Fitch would like to retain the term "Synthetic Theory" to refer to the expanded version of the Modern Synthesis. They want to emphasize that there have been important extensions to the original Modern Synthesis but these are merely add-ons. Darwin's basic idea of evolution by natural selection remains at the core of their version of the "Theory of Evolution."

That seems like a very pluralistic view but I'd like to note several things about this paper.

1. The word "drift" appears only once and it's in the form "neutral drift." There's no mention of random genetic drift as a mechanism of evolution that's been incorporated into the synthetic version of evolutionary theory.
2. The word "neutral" appears five times but "Neutral Theory" is not mentioned. The authors do concede that "the neutral-selection controversy rages on."
3. There are 50 references but not a single paper by Mootoo Kimura is mentioned. They do, however, discuss molecular clocks and discuss whether amino acid substitutions are really of "no adaptive consequence."
4. There's a fairly well-known paper by Gould and Lewontin that might be relevant in a discussion about the synthetic version modern evolutionary theory. They neglected to mention it.

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Ayala, F.J., and Fitch, W.M. (1997) Genetics and the origin of species: an introduction. Proc. Natl. Acad. Sci. (USA) 94:7691-7697. [PDF]

Gould, S.J., and Lewontin, R.C. (1979) The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proc. Roy. Soc. (London) Series B. Biological Sciences 205:581-598. [doi: 10.1098/rspb.1979.0086]