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Author Topic:   PZ Myers vs. Adaptationism
MrHambre
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Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 16 of 49 (763223)
07-22-2015 3:26 PM
Reply to: Message 15 by AZPaul3
07-22-2015 3:05 PM


Re: Spandrels and Storytelling
AZPaul3 writes:

quote:
but no one is disputing that adaptive features are the result of natural selection.

Maybe I'm reading this wrong but isn't this exactly what Prof. M is disputing?


I don't believe so. In the lecture, Myers quotes Michael Lynch to the effect that an adaptive evolutionary force is one that is a function of the fitness properties of individuals. In that sense, your distinction between having a nose and the specific shape of the nose is relevant: if the organ itself has selective value, it's an adaptation; if the shape doesn't have a selective value, then it isn't.
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Dr Adequate
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Posts: 15984
Joined: 07-20-2006
Member Rating: 4.2


Message 17 of 49 (763226)
07-22-2015 3:59 PM
Reply to: Message 9 by MrHambre
07-22-2015 10:34 AM


Re: Spandrels and Storytelling
Um, but no one is disputing that adaptive features are the result of natural selection.

You said that attributing adaptation to natural selection was tautologous. The fact that we can imagine alternative causes shows that it is not.

What's being refuted here is the notion that natural selection is all-important to evolution because it's responsible for adaptation. Adaptation is not synonymous with evolution.

That may be what you're trying to refute, but it's not what Dawkins said.

But the question I asked is, How does Dawkins know natural selection is the only explanation for the phenomena he described?

Because he is talking about adaptation, not about all evolutionary phenomena.


This message is a reply to:
 Message 9 by MrHambre, posted 07-22-2015 10:34 AM MrHambre has responded

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 Message 19 by MrHambre, posted 07-22-2015 4:56 PM Dr Adequate has responded

  
Taq
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Posts: 7272
Joined: 03-06-2009
Member Rating: 3.9


Message 18 of 49 (763228)
07-22-2015 4:00 PM
Reply to: Message 15 by AZPaul3
07-22-2015 3:05 PM


Re: Spandrels and Storytelling
Maybe I'm reading this wrong but isn't this exactly what Prof. M is disputing? Adaptationists insist there is a fitness value to all adaptations in your body or they wouldn't be there. This leads most adaptationists to posit selective pressures (natural selection) on the most flimsy of bases.

We could look at this through the eyes of evo-devo.

Of the genes involved in developmental pathways responsible for physical traits, how many show evidence of selection against deleterious mutations? My own expectations is that a vast majority of developmental genes show evidence of selection at the sequence level.

What Prof. M is saying, by my reading, is that having or not having a nose may be a major adaptation which helps define a species and is a major selective determinant in passing through the sieve of natural selection (fitness), but the (beautiful) angle of the bridge of his nose has little to no selective value to fitness and this adaptation merely drifts through the future population as a function of the probabilities in meiosis and fecundity.

IOW, there is more of a fitness mesa instead of a fitness peak.


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MrHambre
Member
Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 19 of 49 (763233)
07-22-2015 4:56 PM
Reply to: Message 17 by Dr Adequate
07-22-2015 3:59 PM


Re: Spandrels and Storytelling
Dr Adequate writes:

You said that attributing adaptation to natural selection was tautologous.


Nope. I've said a few times (per Myers in the video) that adaptations are the result of natural selection. The tautology I described was Dawkins's saying that natural selection was important when it came to 'changes that affect survival and reproduction,' (i.e. adaptations) when the definition of adaptation presupposes that the changes have been selected for. Much as I'd love to play But Then I Said with you all day, I'll have to pass.

Because he is talking about adaptation, not about all evolutionary phenomena.

Okay. But he only mentioned 'beauty' and 'complexity,' which aren't in and of themselves adaptations. If you assume they're adaptations, then I guess natural selection is the clear explanation.
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Dr Adequate
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Posts: 15984
Joined: 07-20-2006
Member Rating: 4.2


Message 20 of 49 (763235)
07-22-2015 5:35 PM
Reply to: Message 19 by MrHambre
07-22-2015 4:56 PM


Re: Spandrels and Storytelling
The tautology I described was Dawkins's saying that natural selection was important when it came to 'changes that affect survival and reproduction,' (i.e. adaptations) when the definition of adaptation presupposes that the changes have been selected for.

No it doesn't. Lamarkian evolution, as I pointed out, would also produce adaptation. So would front-loaded evolution. So would Michael Behe's invisible Tinkerer With Things.

This is why when Darwin explained his theory the response was not everyone in the world saying "You are right by definition and therefore we are unable to argue with you or suggest any alternatives."

Okay. But he only mentioned 'beauty' and 'complexity,' which aren't in and of themselves adaptations.

No, he said "functional beauty and apparently "designed" complexity"


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MrHambre
Member
Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 21 of 49 (763414)
07-24-2015 3:28 PM
Reply to: Message 12 by New Cat's Eye
07-22-2015 1:57 PM


Design Flaws
Cat Sci writes:

quote:
How does Dawkins know natural selection is the only explanation for the phenomena he described?

Because they look designed. The stuff that results from things like genetic drift doesn't look designed.

According to biologists, it's not that easy, because drift and selection aren't always competing forces. Evolutionary biologist and herpetologist John O. Reiss considers the processes nearly indistinguishable in practice. In Not By Design: Retiring Darwin's Watchmaker, Reiss notes that the concept of naturalized design has all the teleological vestiges of the intelligent design paradigm that Darwin's theory supposedly demolished. Selection as the engine of a population's uphill struggle in an adaptive landscape is just the sort of goal-oriented rhetoric that's inappropriate in describing evolution by natural selection.


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Tangle
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Posts: 5234
From: UK
Joined: 10-07-2011
Member Rating: 2.2


Message 22 of 49 (763416)
07-24-2015 4:00 PM
Reply to: Message 21 by MrHambre
07-24-2015 3:28 PM


Re: Design Flaws
MrHambre writes:

Selection as the engine of a population's uphill struggle in an adaptive landscape is just the sort of goal-oriented rhetoric that's inappropriate in describing evolution by natural selection.

This is just nonsense. You appear to approach every topic with a agenda that first requires a straw man to be erected then defended despite no-one actually taking the staunch positions you would like them to take. What's the problem?

It's been conventional biological knowledge for a couple of generations that there is more than one source of evolution - no modern biologist would disagree, including Dawkins.

There's nothing to see here.


Je suis Charlie. Je suis Ahmed. Je suis Juif.

Life, don't talk to me about life - Marvin the Paranoid Android

"Science adjusts it's views based on what's observed.
Faith is the denial of observation so that Belief can be preserved."
- Tim Minchin, in his beat poem, Storm.


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caffeine
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Posts: 1356
From: Prague, Czech Republic
Joined: 10-22-2008
Member Rating: 3.8


Message 23 of 49 (763417)
07-24-2015 4:02 PM


An argument about nothing
I can't help but feel that this is one of those arguments about absolutely nothing that plague many fields. That's consider the facts that every single biologist in the world agrees on:

1. Natural selection is an important part of the explanation for to diversity of life we see today.

2. The more fit a trait is, the greater the chance of it spreading to fixation.

3. Evolutionary change is constrained by existing function.

4. Not every trait of every organism is adaptively relevant.

All I can see that's left is an aesthetic argument about the style in which people present their views. If we want to talk about something specific - some particular trait where an adaptive explanation is widely assumed but has not been demonstrated - then there's something to have a conversation about. Without this, the whole topic is just a bunch of empty words.


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MrHambre
Member
Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 24 of 49 (763419)
07-24-2015 4:16 PM
Reply to: Message 23 by caffeine
07-24-2015 4:02 PM


Re: An argument about nothing
caffeine writes:

I can't help but feel that this is one of those arguments about absolutely nothing that plague many fields.[...]the whole topic is just a bunch of empty words.


And the fact is that there continues to be heated debate about these matters in biology. Maybe the reason we can dismiss the entire issue as irrelevant is that we're far removed from the academic battlefields in which it takes place, and the controversy is just not sexy enough for major media attention. It could also be that we're much happier browbeating religious people for their incoherent grasp of modern biology than delving into subjects that real scientists like PZ Myers and John O. Reiss (among many others) take to heart.
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 Message 23 by caffeine, posted 07-24-2015 4:02 PM caffeine has responded

Replies to this message:
 Message 25 by caffeine, posted 07-24-2015 4:53 PM MrHambre has responded
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caffeine
Member
Posts: 1356
From: Prague, Czech Republic
Joined: 10-22-2008
Member Rating: 3.8


Message 25 of 49 (763424)
07-24-2015 4:53 PM
Reply to: Message 24 by MrHambre
07-24-2015 4:16 PM


Re: An argument about nothing
And the fact is that there continues to be heated debate about these matters in biology. Maybe the reason we can dismiss the entire issue as irrelevant is that we're far removed from the academic battlefields in which it takes place, and the controversy is just not sexy enough for major media attention. It could also be that we're much happier browbeating religious people for their incoherent grasp of modern biology than delving into subjects that real scientists like PZ Myers and John O. Reiss (among many others) take to heart.

Or, there could be no meaningful debate going on at all. which seems much more likely to me, having heard Dawkins and Gould argue about adapatationism without giving any sign that they actually disagreed on anything substantive.

Now, one point Gould did make well is that some biologists are too quick to accept a plausible adaptive explanation without any evidence. But if this is all you want to say, no one will disagree with you. And that's because this isn't a fundamental issue in biology that's ignored because it's not sexy enough. On the contrary, it's a sexed-up argument about labels between people who do not disagree on things that actually matter.


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 Message 24 by MrHambre, posted 07-24-2015 4:16 PM MrHambre has responded

Replies to this message:
 Message 27 by MrHambre, posted 07-25-2015 8:50 AM caffeine has responded

  
Tangle
Member
Posts: 5234
From: UK
Joined: 10-07-2011
Member Rating: 2.2


(2)
Message 26 of 49 (763426)
07-24-2015 5:03 PM
Reply to: Message 24 by MrHambre
07-24-2015 4:16 PM


Re: An argument about nothing
Cobblers, there's no controversy.

If you really need to find a punch up involving evolution and Dawkins have a look at group selection.

But this is just how science and journalism works, there's no need for the rest of us to fall for the bollox.


Je suis Charlie. Je suis Ahmed. Je suis Juif.

Life, don't talk to me about life - Marvin the Paranoid Android

"Science adjusts it's views based on what's observed.
Faith is the denial of observation so that Belief can be preserved."
- Tim Minchin, in his beat poem, Storm.


This message is a reply to:
 Message 24 by MrHambre, posted 07-24-2015 4:16 PM MrHambre has not yet responded

  
MrHambre
Member
Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 27 of 49 (763468)
07-25-2015 8:50 AM
Reply to: Message 25 by caffeine
07-24-2015 4:53 PM


The Emperor's Fashion Sense
caffeine writes:

Or, there could be no meaningful debate going on at all. which seems much more likely to me, having heard Dawkins and Gould argue about adapatationism without giving any sign that they actually disagreed on anything substantive.

Or, it could be that the distinctions are too subtle for people like us, who are more comfortable having arguments with people who think the Earth is only a few thousand years old and that species were each created de novo by a Big Magic Guy. Philosophical differences we consider meaningful and substantive and those that generate debate in the expert community are probably very different. People like PZ Myers and John O. Reiss aren't religious nutbags or Discovery Institute cranks. But maybe that's exactly why you can't work up interest in understanding their arguments. In any case, since they're PhDs in evolutionary biology, I have no qualms about giving them the benefit of the doubt for the legitimacy of their gripes.

it's a sexed-up argument about labels between people who do not disagree on things that actually matter.

If you're defining things that actually matter as topics that generate flamewars between peevish amateurs on message boards, I suppose you're right. But I think this subject is one that can't be dismissed in such a cavalier way. Yes, the people debating all affirm the notion of common ancestry and the rough outline of the random-variation-natural-selection idea. But the problems in the way we atomize organisms and conceptualize the relation between adaptation and evolution remain, and they rankle scientists like PZ Myers who insist on people getting it all right.


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caffeine
Member
Posts: 1356
From: Prague, Czech Republic
Joined: 10-22-2008
Member Rating: 3.8


Message 28 of 49 (764231)
07-27-2015 7:43 AM
Reply to: Message 27 by MrHambre
07-25-2015 8:50 AM


Re: The Emperor's Fashion Sense
Or, it could be that the distinctions are too subtle for people like us, who are more comfortable having arguments with people who think the Earth is only a few thousand years old and that species were each created de novo by a Big Magic Guy. Philosophical differences we consider meaningful and substantive and those that generate debate in the expert community are probably very different. People like PZ Myers and John O. Reiss aren't religious nutbags or Discovery Institute cranks. But maybe that's exactly why you can't work up interest in understanding their arguments. In any case, since they're PhDs in evolutionary biology, I have no qualms about giving them the benefit of the doubt for the legitimacy of their gripes.

Amongst the things people with PhDs argue about is whether Cyanidiales are a phylum, a sub-phylum or a class of algae, and as such whether they should be known as Cyanidiales, Cyanidophyta or Cyanidiophyceae. Now, given that we know for a fact that this is an argument about nothing substantive, and yet educated people with PhDs are happy to blether about it, clearly the possession of a PhD is not sufficient to stop people having arguments about style and presentation rather than about factual matters. I’ll need more than an appeal to authority to convince me.


This message is a reply to:
 Message 27 by MrHambre, posted 07-25-2015 8:50 AM MrHambre has responded

Replies to this message:
 Message 29 by MrHambre, posted 07-27-2015 10:22 AM caffeine has responded

  
MrHambre
Member
Posts: 1494
From: Framingham, MA, USA
Joined: 06-23-2003


Message 29 of 49 (765253)
07-27-2015 10:22 AM
Reply to: Message 28 by caffeine
07-27-2015 7:43 AM


Re: The Emperor's Fashion Sense
caffeine writes:

I’ll need more than an appeal to authority to convince me.

Well, as long as we're talking about convincing, it's not like you offered anything other than your own opinion to support your claim that "the whole topic is just a bunch of empty words." I at least posted a video of a talk PZ Myers gave, outlining his reasoning. He's talking about things that go to the heart of how we understand natural history: the way we explain fitness in organisms and populations, the way we conceptualize design in nature, and the way we define the relationship between adaptation and evolution. You haven't addressed a single one of his points. You just said that since there's a large amount of agreement among biologists, by definition this isn't a substantive debate. Later you added the corollary that since PhDs argue about things you consider silly, there's no reason to think they argue about anything you wouldn't consider silly. Am I allowed to ask why your opinion is assumed to be the standard for relevance in this matter? Is argumentum ad caffeinam really that much better than appeals to legitimate expertise?


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 Message 28 by caffeine, posted 07-27-2015 7:43 AM caffeine has responded

Replies to this message:
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RAZD
Member
Posts: 19295
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 2.3


Message 30 of 49 (765318)
07-27-2015 11:16 AM
Reply to: Message 9 by MrHambre
07-22-2015 10:34 AM


Lousy recording
First off I found the sound track more of a distraction than anything said. Almost quit several times, and wish I had as I did not see anything really substantive.

The cute argument about the nose ignores cultural standards of beauty as a measure of reproductive desire ... with different standards in different cultures showing different preferences for the shape and size of noses.

The argument that female orgasms have no selective advantage ignores the willingness of participants to repeat experiences that are pleasant and avoid experiences that are not. It may be that it "came along for the ride" with selection for male orgasm, but once in the mix it does have sexual selection advantages: more breeding → more offspring.

And we know from observing Bonobos behavior that this isn't just a human reaction.

To my mind selection operates to trend towards stasis in any stable ecology for species, and it is only when you have changing ecologies, or emigration to new ecologies, that things change.

In comparison, drift operates to trend towards random distribution of traits and potential loss of traits that are/were adaptive, so it trends away from stasis. This becomes more apparent in separated populations, especially when one population is small (founder effect).

In this way drift would be more important to the development of (non-deleterious) variations within a population, and hence maybe more important to speciation than selection.

If a trait persists in a population from generation to generation it is in effect selected, regardless of relative adaptive benefit/cost.

Non-beneficial traits/genes get selected when they are bundled with ones that have high beneficial/selective value: is this selection or drift or a combination?

Or is it just perspective? Species and individuals survive and breed because they are capable of surviving and breeding, not because they are becoming better "adapted" or because they are becoming more "fit" ... the "goal" is survival are reproduction not fitness\adaptation.

Enjoy


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