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Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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Author | Topic: extended evolutionary synthesis (EES) | |||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Does evolutionary theory need a rethink?
Nature | Comment 08 October 2014 quote: Sounds like Evo\Devo to me, being incorporated into a new synthesis theory, just as gene theory was previously incorporated in the "modern synthesis" and the development of SET (standard evolutionary theory).
quote: In other words, the field of evolution is evolving as more information becomes available on the different processes involved, just as all sciences do, and that rather than just mutation and selection the processes involve:
To my mind many of these "add-on" processes involve the interaction of the organisms with their ecology, and this is really recognition that species cannot be talked about properly without including their ecologies. Does this need to be updated?
The process of evolution involves changes in the composition of hereditary traits, and changes to the frequency of their distributions within breeding populations from generation to generation, in response to ecological challenges and opportunities. And if so, how? Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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AdminModulous Administrator Posts: 897 Joined:
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Thread copied here from the extended evolutionary synthesis (EES) thread in the Proposed New Topics forum.
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nwr Member Posts: 6408 From: Geneva, Illinois Joined: Member Rating: 5.1 |
There's not a lot of discussion on this thread
I thought that Laland made an unpersuasive argument. That is to say, I was not persuaded.
We hold that organisms are constructed in development, not simply ‘programmed’ to develop by genes.
Undoubtedly, this is true. But I have long assumed that this was well known, except among creationists. So I don't see this as enough reason for the proposed change.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
There's not a lot of discussion on this thread I thought that Laland made an unpersuasive argument. That is to say, I was not persuaded.
We hold that organisms are constructed in development, not simply ‘programmed’ to develop by genes.
Undoubtedly, this is true. But I have long assumed that this was well known, except among creationists. So I don't see this as enough reason for the proposed change. So you agree with Wray and Hoekstra that current "standard evolutionary theory" thinking includes their "extended evolutionary synthesis" arguments, ... and therefor that my summary process doesn't need changes\alterations\additions:
The process of evolution involves changes in the composition of hereditary traits, and changes to the frequency of their distributions within breeding populations from generation to generation, in response to ecological challenges and opportunities. ie -- I don't need to include reference to developmental stages and their interaction with the ecological conditions ...
I thought that Laland made an unpersuasive argument. That is to say, I was not persuaded. My opinion is that some of these processes he discusses apply to some species but not to all, and as such they are ancillary additional processes that explain those certain instances, but they are not significant enough to combine in a new overall synthesis in the way that genetics was. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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nwr Member Posts: 6408 From: Geneva, Illinois Joined: Member Rating: 5.1
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So you agree with Wray and Hoekstra that current "standard evolutionary theory" thinking includes their "extended evolutionary synthesis" arguments Yes.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
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herebedragons Member (Idle past 857 days) Posts: 1517 From: Michigan Joined:
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Hi RAZD
My thinking is that that evolutionary theory does need a rethink, but not for the purpose of correcting something that is flawed, or even incomplete, but for the purpose of providing better and more effective focus. The general statement of evolution you provided
quote: is accurate enough and it does take into consideration all the environmental effects and "add-on" processes. It works well as a general definition but I think it fails to capture the complexity and nuances of evolutionary processes. So in essence I agree with Laland's statement that:
quote: It is a shift in focus, not in definition. I think that in reality this shift is already happening and this proposal for an EES is actually a matter of the academic side - the framework aspect - catching up with what is really happening on the ground. While not about evolution directly, but as an example of how the focus is shifting in the study of biological systems; I am currently studying plant pathology. Although the definition maybe something like: The study of infectious plant diseases caused by pathogens and environmental conditions, this fails to capture the real nature of disease studies. In order to really understand disease epidemiology we can no longer simply look at the plant - pathogen interaction; it must include a whole range of biotic and abiotic factors. The focus of pathology is shifting to a community or a biome approach rather than simply a pathogen - plant interaction. I see the same type of thing happening in evolution. Another good example is in molecular biology. The central dogma of molecular biology is that genes make RNA which makes protein. And this is certainly true. But it totally fails to express the complexity and interdependence of molecular processes. This simplistic thinking can lead to erroneous thinking about things like junk-DNA, which we now know is wrong. Even regions like intergenic spacers that are never expressed into gene products of any kind play an important role in gene regulation, as buffers against harmful mutations, etc. Molecular biology can no longer focus on genes and their products alone, but needs to take a whole genome approach to understanding how molecular processes function. I think that is the kind of thing a revision or extension of the evolutionary synthesis would do for biology. It would shift focus to a much broader perspective and I believe would help develop new insights as to how and why organisms change over time. However, I do agree with Wray and Hoekstra when they say:
quote: I don't see that there is division and difficulty in evolutionary biology, rather it seems more like it is time to integrate our current knowledge of evolutionary processes into a more inclusive framework. I see this as a "soft revolution" in evolutionary biology, not a shake-up of the discipline. I see it as a way to help develop and expand our focus and so have a better understanding of evolutionary processes. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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herebedragons Member (Idle past 857 days) Posts: 1517 From: Michigan Joined:
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My opinion is that some of these processes he discusses apply to some species but not to all, and as such they are ancillary additional processes that explain those certain instances, I am not sure that is true and I think that may be where our focus does need to change. I would say that those "add-on" processes DO apply to all species, just in varying levels of effect - sometimes the effect may be virtually nothing, but it is still part of the overall process. An example I thought of is that we would say that the earth's moon has virtually no effect on the orbit of Jupiter; we could essentially say that the gravity of the earth's moon does not apply to the orbit of Jupiter. But what would happen if we suddenly took the moon out of the system? A chain of events would occur that would most certainly affect the orbit of Jupiter.
but they are not significant enough to combine in a new overall synthesis in the way that genetics was. And that is Wray and Hoekstra's argument that genes are the major players, which I still agree with. But these "ancillary processes" I don't consider to be add-ons or secondary processes, but part of the bigger picture, without which genes and their products would not have a context in which to operate. That is what I see an extended synthesis helping to achieve: congealing these ancillary processes into a cohesive and comprehensive framework that provides a better picture of the overall process of evolution. And as I pointed out, Wray and Hoekstra do call for an extended synthesis, but they are suggesting, as am I, that it is not particularly revolutionary new concepts, but an expansion of the basic framework. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined:
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My thinking is that that evolutionary theory does need a rethink, ... for the purpose of providing better and more effective focus. The general statement of evolution you provided ... is accurate enough ... but I think it fails to capture the complexity and nuances of evolutionary processes. It is a shift in focus, not in definition. I think that in reality this shift is already happening and this proposal for an EES is actually a matter of the academic side - the framework aspect - catching up with what is really happening on the ground. ... The focus of pathology is shifting to a community or a biome approach rather than simply a pathogen - plant interaction. I see the same type of thing happening in evolution. I don't see that there is division and difficulty in evolutionary biology, rather it seems more like it is time to integrate our current knowledge of evolutionary processes into a more inclusive framework. I see this as a "soft revolution" in evolutionary biology, not a shake-up of the discipline. I see it as a way to help develop and expand our focus and so have a better understanding of evolutionary processes. I agree. An evolution in the way different aspects of biology are viewed as part of a whole, a synergistic view. This would of course include evo-devo and ecology in talking about any species, thus broadening the scope from species to species within habitat and interactions with other species in those habitats. Curiously, I must admit that I was a little concerned\unhappy that the last phrase in my pet definition didn't go quite far enough for including interactions and the feedback of ecology. So I thought about expanding it slightly ...
The process of evolution involves changes in the composition of hereditary traits, and changes to the frequency of their distributions within breeding populations from generation to generation, in an iterative feedback response to the different ecological challenges and opportunities for growth, development, survival and reproductive success in changing or different habitats. Hopefully this is not getting too wordy. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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herebedragons Member (Idle past 857 days) Posts: 1517 From: Michigan Joined: |
The process of evolution involves changes in the composition of hereditary traits, and changes to the frequency of their distributions within breeding populations from generation to generation, in an iterative feedback response to the different ecological challenges and opportunities for growth, development, survival and reproductive success in changing or different habitats. I like that, especially the phrase "feedback response," it reflects the point that evolution is not a one-way street, but is a complex interaction where the organism effects their environment, the environment affects the organism, the organism affects other organisms, etc, etc. I am not sure about "iterative" though. I suppose you are trying to express the step-wise nature and the idea that more than one type of evolutionary development can be going on at one time (even contradictory trajectories), but I'm not sure.
This would of course include evo-devo and ecology in talking about any species I find evo-devo to be one of the most fascinating and promising aspects of evolutionary biology. In theory, two organisms could have identical genes and yet develop vastly different organisms depending on which genes are turned on and when - that is, how those gene products are assembled during development. HOW organisms regulate their genes and how they organize gene products is the key to their phenotype and therefore, their evolutionary advantage or disadvantage. And honestly, it stills seems a bit of a "black box," although we are slowly unraveling it. Unfortunately, I don't really have the time to spend on that particular aspect. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
... I am not sure about "iterative" though. ... Just referring to generation by generation, step by step ... mutate, survive, reproduce, repeat ... an endless do-loop. Also the way evolution computer programs work.
... In theory, two organisms could have identical genes and yet develop vastly different organisms depending on which genes are turned on and when - that is, how those gene products are assembled during development. HOW organisms regulate their genes and how they organize gene products is the key to their phenotype and therefore, their evolutionary advantage or disadvantage. ... And how different habitat\ecologies affect the development process. I read somewhere that once an individual reaches sexual maturity that any delayed development stops. This would be a mechanism for neoteny to develop. This also explains the retained gills in Axolotls Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
An evolution in the way different aspects of biology are viewed as part of a whole, a synergistic view. This would of course include evo-devo and ecology in talking about any species, thus broadening the scope from species to species within habitat and interactions with other species in those habitats. In my eyes, this is nothing more than discussing the complexity of natural selection. Some scientists want to treat the interaction of environment and genotype as an additional mechanism, but in the end I fail to see how it is any different than other selective pressures. As an hypothetical, let's say that there is a developmental gene that causes newborns to have webbed feet if their mothers were in the water a lot. Obviously, this would be selected for. However, if the same phenotype were stimulated by desert conditions, then the trait would be selected against. In the end, each is a mutation that is passed through selection. Edited by Taq, : No reason given.
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined:
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Thanks for your information on ebola\vaccines btw - I must admit to a layman's understanding in that field. Always room to learn eh?
In my eyes, this is nothing more than discussing the complexity of natural selection. Some scientists want to treat the interaction of environment and genotype as an additional mechanism, but in the end I fail to see how it is any different than other selective pressures. What I see is that the "old school" view was that survival and reproduction were solely in the hands of the individuals of a breeding population, reacting to the ecology they inhabited, fighting against nature, red in tooth and claw ... And the "new school" (both the SET and EES advocates in the article) view is that there is an interplay and that it is more of a symbiotic\partnership relationship, where organisms can alter the selective pressures by affecting the habitat to make it more beneficial to them, a feedback\cooperative interaction dance with multiple partners.
Wolves in Yellowstone for example.
As an hypothetical, let's say that there is a developmental gene that causes newborns to have webbed feet if their mothers were in the water a lot. Obviously, this would be selected for. However, if the same phenotype were stimulated by desert conditions, then the trait would be selected against. In the end, each is a mutation that is passed through selection. For example, several varieties of dogs in coastal areas have webbed feet -- The Newfoundland Dog for example, that also has thick double coat, and slight modification to shoulders and lungs for stronger swimming ability. But this is just species against nature in this regard, whereas a more synergistic approach would look at the coastal ecology and see if these dogs affect it to their advantage - food sources etc - or other animals that are displaced (sea otters?) and how that changes the ecosystem. Enjoy. by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
And the "new school" (both the SET and EES advocates in the article) view is that there is an interplay and that it is more of a symbiotic\partnership relationship, where organisms can alter the selective pressures by affecting the habitat to make it more beneficial to them, a feedback\cooperative interaction dance with multiple partners. Darwin himself spoke of the interplay between symbiotes, parasites, inter- and intraspecies cooperation, and environment. That's as old school as it gets.
But this is just species against nature in this regard, whereas a more synergistic approach would look at the coastal ecology and see if these dogs affect it to their advantage - food sources etc - or other animals that are displaced (sea otters?) and how that changes the ecosystem. Which genes get passed on in a changing environment is once again up to natural selection (and neutral drift). The EES just seems to be be another way of saying, "Boy, natural selection can be really complex." I think we have known that for a long time now, and the old synthesis certainly didn't argue otherwise.
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herebedragons Member (Idle past 857 days) Posts: 1517 From: Michigan Joined:
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Darwin himself spoke of the interplay between symbiotes, parasites, inter- and intraspecies cooperation, and environment. That's as old school as it gets. I had a biology professor who used to say "Biology is the study of plants and their parasites." which I just find very amusing. Anyway, I don't think Darwin understood how deep those interactions actually go. I don't think we really understood it in general until the '60s. Silent Spring was kind of the turning point in our thinking about ecological and environmental matters as far as interaction and inter-dependency of species. It is not that we didn't know about interactions, symbiotes, parasites, etc. before that, but we began to understand the extent and significance of those interactions.
taq writes: In my eyes, this is nothing more than discussing the complexity of natural selection. Some scientists want to treat the interaction of environment and genotype as an additional mechanism, but in the end I fail to see how it is any different than other selective pressures. That's the thing though, selection works on phenotype, not genotype. We are just beginning to unravel the complexities of environment / phenotype interactions, such as methylation, epigenetics and development. It is not so much that these are different than other selective pressures or that they are additional mechanisms, it is just a matter of bringing the whole picture into focus - a "not missing the forest for the trees" sort of thing. I see this "whole biome approach" taking shape and becoming more and more integrated into our study of organism and their evolution. So an extended synthesis should simply be an attempt to help focus our efforts in evolutionary biology into a more inclusive, extensive understanding of how and why organisms change. I think the WHY issue is at the heart of the need for an EES. Natural selection working on random mutations, while it may be accurate enough, is simply too basic and unsatisfying. I think we can provide better answers for WHY organisms evolve. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
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Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
Anyway, I don't think Darwin understood how deep those interactions actually go. Then we are really just arguing about a difference in degree and not kind. A few quotes from Origin of Species: "The missletoe is dependent on the apple and a few other trees, but can only in a far-fetched sense be said to struggle with these trees, for if too many of these parasites grow on the same tree, it will languish and die. But several seedling missletoes, growing close together on the same branch, may more truly be said to struggle with each other. As the missletoe is disseminated by birds, its existence depends on birds; and it may metaphorically be said to struggle with other fruit-bearing plants, in order to tempt birds to devour and thus disseminate its seeds rather than those of other plants. In these several senses, which pass into each other, I use for convenience sake the general term of struggle for existence." "What a struggle between the several kinds of trees must here have gone on during long centuries, each annually scattering its seeds by the thousand; what war between insect and insect between insects, snails, and other animals with birds and beasts of prey all striving to increase, and all feeding on each other or on the trees or their seeds and seedlings, or on the other plants which first clothed the ground and thus checked the growth of the trees! Throw up a handful of feathers, and all must fall to the ground according to definite laws; but how simple is this problem compared to the action and reaction of the innumerable plants and animals which have determined, in the course of centuries, the proportional numbers and kinds of trees now growing on the old Indian ruins!" The 3rd chapter describes many examples of just how complex the interaction is between species and environment. http://www.talkorigins.org/faqs/origin/chapter3.html
That's the thing though, selection works on phenotype, not genotype. We are just beginning to unravel the complexities of environment / phenotype interactions, such as methylation, epigenetics and development. It is not so much that these are different than other selective pressures or that they are additional mechanisms, it is just a matter of bringing the whole picture into focus - a "not missing the forest for the trees" sort of thing. That is one reason why I see the EES as completely unnecessary. We already have an understanding of the mechanisms in play. It is just a matter of unwinding the complexity of their interaction. More importantly, the EES is a bit of salesmanship on the part of people such as Wright and Shapiro. This is certainly not the first time salesmanship has been used. In fact, a bit of flash is appreciated by most scientists. However, with the EES there seems to be more flash than substance. It is almost an attempt to save the excitement that was started by the theory of adaptive mutations, which inevitably sank when random mutations were found to be the cause.
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