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Author Topic:   extended evolutionary synthesis (EES)
RAZD
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Message 1 of 20 (738525)
10-11-2014 12:10 PM


Does evolutionary theory need a rethink?
Nature | Comment
08 October 2014

quote:
Researchers are divided over what processes should be considered fundamental.

YES, URGENTLY — Kevin Laland and colleagues

Does evolutionary theory need a rethink? Yes, urgently

Without an extended evolutionary framework, the theory neglects key processes, say Kevin Laland and colleagues.

... we have worked intensively to develop a broader framework, termed the extended evolutionary synthesis^1 (EES), and to flesh out its structure, assumptions and predictions. In essence, this synthesis maintains that important drivers of evolution, ones that cannot be reduced to genes, must be woven into the very fabric of evolutionary theory.

... We hold that organisms are constructed in development, not simply ‘programmed’ to develop by genes. Living things do not evolve to fit into pre-existing environments, but co-construct and coevolve with their environments, in the process changing the structure of ecosystems.

... standard evolutionary theory (SET) largely retains the same assumptions as the original modern synthesis, which continues to channel how people think about evolution.

The story that SET tells is simple: new variation arises through random genetic mutation; inheritance occurs through DNA; and natural selection is the sole cause of adaptation, the process by which organisms become well-suited to their environments. In this view, the complexity of biological development — the changes that occur as an organism grows and ages — are of secondary, even minor, importance.

Plasticity: commodore butterflies emerge with
different colours in dry (left) and wet seasons.

In our view, this ‘gene-centric’ focus fails to capture the full gamut of processes that direct evolution. Missing pieces include how physical development influences the generation of variation (developmental bias); how the environment directly shapes organisms’ traits (plasticity); how organisms modify environments (niche construction); and how organisms transmit more than genes across generations (extra-genetic inheritance). For SET, these phenomena are just outcomes of evolution. For the EES, they are also causes.

Valuable insight into the causes of adaptation and the appearance of new traits comes from the field of evolutionary developmental biology (‘evo-devo’). Some of its experimental findings are proving tricky to assimilate into SET. Particularly thorny is the observation that much variation is not random because developmental processes generate certain forms more readily than others^3. For example, among one group of centipedes, each of the more than 1,000 species has an odd number of leg-bearing segments, because of the mechanisms of segment development^3.

A more succinct hypothesis is that developmental bias and natural selection work together^4,5. Rather than selection being free to traverse across any physical possibility, it is guided along specific routes opened up by the processes of development^5,6.

Another kind of developmental bias occurs when individuals respond to their environment by changing their form — a phenomenon called plasticity. For instance, leaf shape changes with soil water and chemistry. SET views this plasticity as merely fine-tuning, or even noise. The EES sees it as a plausible first step in adaptive evolution. ...

Mathematical models of evolutionary dynamics that incorporate extra-genetic inheritance make different predictions from those that do not^7–9. Inclusive models help to explain a wide range of puzzling phenomena, such as the rapid colonization of North America by the house finch, the adaptive potential of invasive plants with low genetic diversity, and how reproductive isolation is established.

... No longer a protest movement, the EES is now a credible framework inspiring useful work by bringing diverse researchers under one theoretical roof to effect conceptual change in evolutionary biology.


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:
NO, ALL IS WELL — Gregory A. Wray, Hopi E. Hoekstra and colleagues

Does evolutionary theory need a rethink? No, all is well

Theory accommodates evidence through relentless synthesis, say Gregory A. Wray, Hopi E. Hoekstra and colleagues.

In October 1881, just six months before he died, Charles Darwin published his final book. The Formation of Vegetable Mould, Through the Actions of Worms^11 sold briskly: Darwin’s earlier publications had secured his reputation. He devoted an entire book to these humble creatures in part because they exemplify an interesting feedback process: earthworms are adapted to thrive in an environment that they modify through their own activities.

A profound shift in evolutionary thinking began during the 1920s, ... work between 1936 and 1947 culminated in the ‘modern synthesis’, which united Darwin’s concept of natural selection with the nascent field of genetics and, to a lesser extent, palaeontology and systematics. Most importantly, it laid the theoretical foundations for a quantitative and rigorous understanding of adaptation and speciation, two of the most fundamental evolutionary processes.

A worm cast pictured in
Charles Darwin’s final book.

Nonetheless there are evolutionary biologists ... who argue that theory has since ossified around genetic concepts. More specifically, they contend that four phenomena are important evolutionary processes: phenotypic plasticity, niche construction, inclusive inheritance and developmental bias. We could not agree more. We study them ourselves.

New words, old concepts

... all of these concepts date back to Darwin himself, as exemplified by his analysis of the feedback that occurred as earthworms became adapted to their life in soil. ...

Another process, phenotypic plasticity, has drawn considerable attention from evolutionary biologists. Countless cases in which the environment influences trait variation have been documented — from the jaws of cichlid fishes that change shape when food sources alter, to leaf-mimicking insects that are brown if born in the dry season and green in the wet. ...

So, none of the phenomena championed by Laland and colleagues are neglected in evolutionary biology. Like all ideas, however, they need to prove their value in the marketplace of rigorous theory, empirical results and critical discussion. The prominence that these four phenomena command in the discourse of contemporary evolutionary theory reflects their proven explanatory power, not a lack of attention.

Modern expansion

Furthermore, the phenomena that interest Laland and colleagues are just four among many that offer promise for future advances in evolutionary biology. Most evolutionary biologists have a list of topics that they would like to see given more attention. Some would argue that epistasis — complex interactions among genetic variants — has long been under-appreciated. Others would advocate for cryptic genetic variation (mutations that affect only traits under specific genetic or environmental conditions). Still others would stress the importance of extinction, or adaptation to climate change, or the evolution of behaviour. The list goes on.

We could stop and argue about whether ‘enough’ attention is being paid to any of these. Or we could roll up our sleeves, get to work, and find out by laying the theoretical foundations and building a solid casebook of empirical studies. ...

Genes are central

Finally, diluting what Laland and colleagues deride as a ‘gene-centric’ view would de-emphasize the most powerfully predictive, broadly applicable and empirically validated component of evolutionary theory. Changes in the hereditary material are an essential part of adaptation and speciation. The precise genetic basis for countless adaptations has been documented in detail, ranging from antibiotic resistance in bacteria to camouflage coloration in deer mice, to lactose tolerance in humans.

Although genetic changes are required for adaptation, non-genetic processes can sometimes play a part in how organisms evolve. Laland and colleagues are correct that phenotypic plasticity, for instance, may contribute to the adaptedness of an individual. A seedling might bend towards brighter light, growing into a tree with a different shape from its siblings’. Many studies have shown that this kind of plasticity is beneficial, and that it can readily evolve if there is genetic variation in the response^14. This role for plasticity in evolutionary change is so well documented that there is no need for special advocacy.

Lack of evidence also makes it difficult to evaluate the role that developmental bias may have in the evolution (or lack of evolution) of adaptive traits. Developmental processes, based on features of the genome that may be specific to a particular group of organisms, certainly can influence the range of traits that natural selection can act on. However, what matters ultimately is not the extent of trait variation, nor even its precise mechanistic causes. What matters is the heritable differences in traits, especially those that bestow some selective advantage. Likewise, there is little evidence for the role of inherited epigenetic modification (part of what was termed ‘inclusive inheritance’) in adaptation: we know of no case in which a new trait has been shown to have a strictly epigenetic basis divorced from gene sequence. ...

All four phenomena that Laland and colleagues promote are ‘add-ons’ to the basic processes that produce evolutionary change: natural selection, drift, mutation, recombination and gene flow. None of these additions is essential for evolution, but they can alter the process under certain circumstances. For this reason they are eminently worthy of study.

We invite Laland and colleagues to join us in a more expansive extension, rather than imagining divisions that do not exist. We appreciate their ideas as an important part of what evolutionary theory might become in the future. We, too, want an extended evolutionary synthesis, but for us, these words are lowercase because this is how our field has always advanced^16.


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:

  1. selection - survival and reproduction,
  2. genetic drift - stociastic effects,
  3. gene change by mutation and recombination,
  4. gene flow and population dynamics,
  5. phenotypic plasticity and response to environmental changes,
  6. niche (re)construction,
  7. inclusive inheritance or extra-genetic inheritance, such as evolution of behaviour, memes,
  8. developmental bias, how the way an organism evolves is related\confined by how it develops from egg to adult,
  9. epistasis — complex interactions among genetic variants
  10. cryptic genetic variation (mutations that affect only traits under specific genetic or environmental conditions)
  11. extinction vs adaptation to ecological change, and the ability to adapt,
  12. etc.

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?

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
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Replies to this message:
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Message 2 of 20 (738527)
10-11-2014 2:31 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the extended evolutionary synthesis (EES) thread in the Proposed New Topics forum.
    
nwr
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Posts: 5521
From: Geneva, Illinois
Joined: 08-08-2005
Member Rating: 6.5


Message 3 of 20 (738568)
10-12-2014 10:54 AM
Reply to: Message 1 by RAZD
10-11-2014 12:10 PM


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
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Posts: 18472
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Joined: 03-14-2004
Member Rating: 3.7


Message 4 of 20 (738570)
10-12-2014 11:16 AM
Reply to: Message 3 by nwr
10-12-2014 10:54 AM


no change required
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.

Enjoy


we are limited in our ability to understand
by our ability to understand
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nwr
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Posts: 5521
From: Geneva, Illinois
Joined: 08-08-2005
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(1)
Message 5 of 20 (738571)
10-12-2014 11:47 AM
Reply to: Message 4 by RAZD
10-12-2014 11:16 AM


Re: no change required
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
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(2)
Message 6 of 20 (738817)
10-16-2014 8:35 AM
Reply to: Message 1 by RAZD
10-11-2014 12:10 PM


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:
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.

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:
In essence, this [new] synthesis maintains that important drivers of evolution, ones that cannot be reduced to genes, must be woven into the very fabric of evolutionary theory.

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:
We invite Laland and colleagues to join us in a more expansive extension, rather than imagining divisions that do not exist. We appreciate their ideas as an important part of what evolutionary theory might become in the future. We, too, want an extended evolutionary synthesis, but for us, these words are lowercase because this is how our field has always advanced.

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.

HBD


Whoever 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
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Posts: 1324
From: Michigan
Joined: 11-22-2009
Member Rating: 6.0


(1)
Message 7 of 20 (738819)
10-16-2014 9:12 AM
Reply to: Message 4 by RAZD
10-12-2014 11:16 AM


Re: no change required
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.

HBD


Whoever 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.


This message is a reply to:
 Message 4 by RAZD, posted 10-12-2014 11:16 AM RAZD has acknowledged this reply

  
RAZD
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From: the other end of the sidewalk
Joined: 03-14-2004
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(2)
Message 8 of 20 (738832)
10-16-2014 11:50 AM
Reply to: Message 6 by herebedragons
10-16-2014 8:35 AM


extended awareness of biom\ecology interactions
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.

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
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 Message 11 by Taq, posted 10-17-2014 4:04 PM RAZD has responded

  
herebedragons
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Posts: 1324
From: Michigan
Joined: 11-22-2009
Member Rating: 6.0


Message 9 of 20 (738848)
10-16-2014 2:21 PM
Reply to: Message 8 by RAZD
10-16-2014 11:50 AM


Re: extended awareness of biom\ecology interactions
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.

HBD


Whoever 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.


This message is a reply to:
 Message 8 by RAZD, posted 10-16-2014 11:50 AM RAZD has responded

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RAZD
Member
Posts: 18472
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.7


Message 10 of 20 (738886)
10-17-2014 8:27 AM
Reply to: Message 9 by herebedragons
10-16-2014 2:21 PM


Re: extended awareness of biom\ecology interactions
... 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

Enjoy


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
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Taq
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Message 11 of 20 (738915)
10-17-2014 4:04 PM
Reply to: Message 8 by RAZD
10-16-2014 11:50 AM


Re: extended awareness of biom\ecology interactions
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
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Posts: 18472
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 3.7


(1)
Message 12 of 20 (738921)
10-17-2014 4:49 PM
Reply to: Message 11 by Taq
10-17-2014 4:04 PM


iterative feedback response to different ecological challenges and opportunities
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.


we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
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This message is a reply to:
 Message 11 by Taq, posted 10-17-2014 4:04 PM Taq has responded

Replies to this message:
 Message 13 by Taq, posted 10-17-2014 5:33 PM RAZD has acknowledged this reply

  
Taq
Member
Posts: 6461
Joined: 03-06-2009
Member Rating: 4.2


Message 13 of 20 (738924)
10-17-2014 5:33 PM
Reply to: Message 12 by RAZD
10-17-2014 4:49 PM


Re: iterative feedback response to different ecological challenges and opportunities
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.


This message is a reply to:
 Message 12 by RAZD, posted 10-17-2014 4:49 PM RAZD has acknowledged this reply

Replies to this message:
 Message 14 by herebedragons, posted 10-21-2014 9:01 AM Taq has responded

  
herebedragons
Member
Posts: 1324
From: Michigan
Joined: 11-22-2009
Member Rating: 6.0


(4)
Message 14 of 20 (739160)
10-21-2014 9:01 AM
Reply to: Message 13 by Taq
10-17-2014 5:33 PM


Re: iterative feedback response to different ecological challenges and opportunities
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.

HBD


Whoever 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.


This message is a reply to:
 Message 13 by Taq, posted 10-17-2014 5:33 PM Taq has responded

Replies to this message:
 Message 15 by Taq, posted 10-21-2014 5:34 PM herebedragons has not yet responded
 Message 16 by zaius137, posted 10-21-2014 11:29 PM herebedragons has responded

  
Taq
Member
Posts: 6461
Joined: 03-06-2009
Member Rating: 4.2


Message 15 of 20 (739211)
10-21-2014 5:34 PM
Reply to: Message 14 by herebedragons
10-21-2014 9:01 AM


Re: iterative feedback response to different ecological challenges and opportunities
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.


This message is a reply to:
 Message 14 by herebedragons, posted 10-21-2014 9:01 AM herebedragons has not yet responded

  
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