Is the theory of punctuated equilibrium a gamechanger for evolutionary biology?

exchemist said:
I suppose the "limits" involved are (i) relative velocities small compared to c and (ii) "weak gravitational fields" (suppose that means only slight curvature of spacetime). There's a discussion of this here: https://physics.stackexchange.com/q...eneral-relativity-exactly-how-wrong-is-newton. (You can see the first responder is quite incensed by the notion that Newton was shown to be "wrong", i.e. that his theory is "false".:))
Click to expand...

Any calmer and I'd be on a slab.

What I have been doing is quoting verbatim what the world's leading experts have to say on that matter and taking their remarks seriously. Indeed, I appear to be the only person present who does.

Other posters such as exchemist are effectively telling us: "Oh, never mind Einstein, Wheeler, and Bohm. They're just exaggerating. They don't know what they're talking about. Listen to me instead."


Exchemist proceeds -- as others do -- to confuse epistemological issues with questions of pure semantics. What we can show to be true, or show to be false, prove, disprove, what we believe, our knowledge, etc (all epistemological matters) are irrelevant to the inconsistency of two assertions (a matter of semantics).

Thus, if the two theories are mutually inconsistent, then one cannot -- on pain of inconsistency and contradiction -- assert both. You have to to take a stand; you have to assert one or the other, not both.

I'll write more about this in the other thread.
 
Last edited:
Pinball1970 said:
No, I have stated that the approaches were different. The back drop w.r.t. the theory was also different as Einstein had published SR 9 years earlier.
Click to expand...

So we are agreed the the two theories (classical Newtonian mechanics vs general relativity) are totally different (even though they yield similar predictions in some circumstances). Right?

Is it possible to assert both? e.g. Can a scientist consistently assert at once, for example. that there is an attractive gravitational force and that there is not an attractive gravitational force? Can a scientist consistently assert at once, for example. that space is absolute and that space is not absolute.

Is it correct to say that if a scientist asserts (or believes) one theory, he must deny the other? - to do otherwise would be inconsistent.

Which one of the two theories do the majority of contemporary physicist assert?
 
axocanth said:
Which one of the two theories do the majority of contemporary physicist assert?
Click to expand...

P.S.

Which of the two theories do you assert, Pinball? E.g. Would you be more inclined to say "I think Einstein's theory is true" or "I think Newton's theory is true"? Or if you prefer "I think our universe is (roughly) as Einstein describes".

Or do you refrain from taking a stance altogether? - both are just useful tools and all talk of truth/falsity is best left to navel-gazing philosophers (oh, and navel-gazing Einstein, Bohm, Wheeler, Thorne, and Greene too).
 
exchemist said:
Needless to say, what all these models share is a degree of explanatory and predictive power concerning observations of nature. A pseudoscience like ID or astrology is incapable of that.
Click to expand...

Exchemist ignores yet another problem though. If we have two or more mutually incompatible models or theories -- e.g. Newton vs Einstein -- then it is not possible that both are true, thus it is not possible that both do any real or genuine explanatory work. Any sense of understanding yielded by the explanations of at least one of them (perhaps both) is entirely specious.

For example, to say that the motion of the planets is explained by both an attractive force and the curvature of spacetime is to contradict oneself. At least one of them (perhaps both) is doing no real explanatory work at all.

Unless of course exchemist wishes to argue that both the "Santa Claus theory" and the "Mummy and Daddy theory" are providing genuine explanations and understanding of what's going on behind the scenes to account for prezzies around the tree on Dec 25.
 
exchemist said:
I suppose the "limits" involved are (i) relative velocities small compared to c and (ii) "weak gravitational fields" (suppose that means only slight curvature of spacetime). There's a discussion of this here: https://physics.stackexchange.com/q...eneral-relativity-exactly-how-wrong-is-newton. (You can see the first responder is quite incensed by the notion that Newton was shown to be "wrong", i.e. that his theory is "false".:))
Click to expand...

axocanth said:
Is it possible to assert both? e.g. Can a scientist consistently assert at once, for example. that there is an attractive gravitational force and that there is not an attractive gravitational force?
Click to expand...
No you can treat the phenomenon as either and get the same results or similar results within a certain domain.

If you are looking at black holes you need Einstein.
Cannon balls you need Newton.
Electrons? You can forget both and use QM because 1. Gravitational effects are small enough to forget and 2. They would not be able to include it in the theory anyway. There is no current quantum theory of gravity, lots of "in progress."
 
Ok, but you haven't addressed some of my questions yet (post #123). Don't worry! I'm not trying to put you in a corner or anything like that. I'm just trying to help us all get more clear about all this. There may be certain consequences of their views that some members haven't fully appreciated yet.

How about this then, Pinball? Do you believe Einstein's theory of general relativity?

First of all, to emphasize again, I'm not asking whether you believe accurate predictions can be derived from the theory (i.e. I'm not asking does it work or is it useful). Everyone believes that! What I'm asking is, do you believe the theoretical account Einstein offers about how our universe really is, i.e., spacetime curvature and all the rest of his ontology?

Here are some possible answers you might consider:

(i) Yes, I believe Einstein's theory (= I think the theory is true).

(Of course, if you choose (i), to be consistent you must assert that Newton's theory is false = I don't believe Newton's theory of gravity)

(ii) I'm agnostic. I am not committed to a belief in the truth of Einstein's (and Newton's) theory.

(iii) No, I don't believe it. (= I think the theory is false).

(iv) Something else. Please elaborate.
 
Last edited:
In post 336 of "The Stage Theory of Theories" I wrote the following:


@ TheVat above

They do say (and S. J. Gould says it somewhere) that when a controversial new view emerges, proposed by Smith say, very often its acceptance happens in three stages:

Stage 1: Opponents vociferously reject what Smith is saying. "Smith is fulla shit. What Smith is saying is outrageously false."

But then it gradually becomes clear that Smith's new view can't be dismissed so easily. So . . .

Stage 2: Opponents concede that what Smith is saying is true, but it's of no importance. It's trivially true. He's saying nothing new.

and then after a few years . . .

Stage 3: Opponents begin to promulgate Smith's view themselves. It's not only important, but they thought of it first. "Yes, I've been saying that for years".


I'd say we're hovering between Stages 2 and 3 [vis-à-vis "there is no such thing as the scientific method" - axo] right now lol.
Click to expand...


For anyone interested S. J. Gould says it (or something similar) on pages 352-3 of his 2007 "Punctuated Equilibrium", and how PE acceptance went through the three stages. I'll type it all out if someone lets me play with their kitten for a day.
 
Something just occurred to me . . .

In response to C C's post #25 (page 2), I wrote the following:

axocanth said:
Gould et al focus on species selection, not group selection -- not the same thing.

Darwin himself had admitted possible cases of group selection. This was nothing new.
Click to expand...

C C replies again in post #36 with this:

C C said:
Yah, I meant "group" in a careless, umbrella sense of covering all possible selection levels (including species) above the individual organism (whereas other collective levels like cells and genes are below the latter). Without taking into account that "group" is a narrower term applied to one of the levels in the hierarchy. etc.
Click to expand...


In good as Gouldian fashion, let me meander a bit before returning to the crux. You'll sometimes hear it said -- indeed you'll routinely hear it said (Aron Rah Rah Rah, etc.) -- that there is no evidence against evolution, or the theory of evolution, or however these things are differentiated this week. Nothing disproves it, all the evidence confirms it, and everyone from Scotland looks like a 1962 Sean Connery. Make of it what you will.

But I suppose one might reasonably argue that the existence of altruism in the animal kingdom, not to mention the human kingdom, sits somewhat awkwardly with a theory that tells us that the fitter organisms prevail in a dog-eat-dog world red in tooth and claw. Look out for number one or you'll get yours! It's the flipside of the coin that the so-called "problem of evil" poses for the "benevolent omnipotent god" theory. If God is so powerful and good there shouldn't be any evil.

And you might reasonably continue that the existence of complete altruism in the sterile worker castes of the hymenoptera (social insects) sits very awkwardly indeed with that theory. Why, if you're a worker ant, say, slaving your life away for the colony, never getting laid, and never even having the possibility of reproducing, this is altruism taken to the limit. Sounds a bit like me, but that's another story. Your expected fitness, then, is zero and your actual fitness is zero. Natural selection, meanwhile, is supposed to ruthlessly winnow out the unfit almost as soon as they rear their do-gooder heads, but kick open any termite mound and watch what happens: they positively teem out!

Charles Darwin was no dummy, of course, was aware of the problem (or "puzzle" if you're a Kuhnian normal scientist), and, if I'm not mistaken, tried to explain it -- or explain it away, if you're a cynic -- by appeal to group selection. The altruism of the individual organisms in the group allows the group as a whole to thrive, or so the idea goes. Other patches were subsequently added in the form of kin selection and inclusive fitness.

(For another devastating critique of the latter two, see David Stove's Darwinian Fairytales again.)

Evidence against evolutionary theory? I'm James Bond! Oh, and in case you were wondering, the God theorists have as many patches to explain away evil as the evolutionists do to explain away altruism.



But now we come to the denouement, ladies and gentlemen. Let's see which one of you mugs (;)) has been paying attention in class, I mean the thread.

Question: Why is species selection not a form of group selection? Why does the species selection, much beloved of PE advocates, not belong under C C's "umbrella". Isn't a species just a big group?


First to answer correctly wins a new bonnet.
 
axocanth said:
Something just occurred to me . . .

In response to C C's post #25 (page 2), I wrote the following:


C C replies again in post #36 with this: [...]
Click to expand...

Even using "multilevel" could potentially run into a similar problem of confusion as "group", when trying to gather these assorted claims under one roof.

At first glance, "multilevel" seems to be a "safe" general signifier without eccentric stipulations. BUT... it has been appropriated as part of the label for a specific scheme or outlook. And the seemingly innocuous generic expression of "hierarchical selection" may or may not be a synonym for that one...

So I'm going to gamble that "stratified selection" (purely in the context of evolution) has not been seized yet by anybody, and thereby is a free (informal) category that can (for practical purposes of communication) subsume all ranks of biological classification that biologists either already have or will contingently in the future attempt to assert that a selective process is taking place at.

So that all of these proposals (both present and future) can finally be referenced or grouped together in one shot (without, again, confusion arising due to _X_ also being the name for a particular one of such).

As these distinct levels rise (gene, cell, multicellular organism, etc), we eventually encounter terms[1] that entail multiple individuals (group, species, etc) but are nevertheless treated as singular entities or units of selection.

Scientists devoted to the gene level -- the so-called "gene centrists" -- critically (and unsurprisingly because of their commitment) regard both group selection and species selection as highly controversial. As Coyne (again) provided examples of:


With respect to "species selection" ... Aside from geographic isolation from the main collective triggering adaptation, a new species may have diverged in such a narrow way that its descendants can longer recover (certain) former physiological features, eating habits, and survival approaches. Forcing it to either resist being a source for further speciation or to be constrained along that limited pathway which could result in yet more radical departures from other fellow species in the same clade (a grouping of multiple species sharing a common ancestor).

- - - footnote - - -

[1] Levels of Selection: Members of a group do not necessarily have to share genes [it's a social division], but the group lives or dies as a function of how their genes (and individuals) interact. Group selection -- a more difficult concept to grasp, is also the subject of an ongoing debate in evolutionary biology. Suffice it to say that selection at the level of groups occurs when a group of individuals produces more groups than other groups. Group selection is a process entirely analogous to individual selection, but acting at the level of groups. Again the traits underlying group selection must be heritable if the species is to evolve by group selection.

Species selection acts at yet a higher level. Members of a species tend to share more genes than two individuals from a different species. Those members of a clade (e.g., a group of closely related species) that produce more species, or perhaps have greater longevity in the earth's history (e.g., lower extinction probability) are going to become overly represented on the planet in much the same way that one allele at a particular genetic locus spreads through a population of individuals and increases in frequency at the expense of alternative alleles.
_
 
Last edited:
Duplicate post deleted here.
_
 
re C C above . . .

axocanth said:
But now we come to the denouement, ladies and gentlemen. Let's see which one of you mugs (;)) has been paying attention in class, I mean the thread.

Question: Why is species selection not a form of group selection? Why does the species selection, much beloved of PE advocates, not belong under C C's "umbrella". Isn't a species just a big group?
Click to expand...


Answer: Because, at least according to those who promote the idea (i.e. the PE mob), species are not groups at all; they are individuals.


Compare with what you quote above:

C C said:
As these distinct levels rise (gene, cell, multicellular organism, etc), we eventually encounter terms[1] that entail multiple individuals (group, species, etc) but are nevertheless treated as singular entities or units of selection.
Click to expand...

Again, according to PE advocates, a species is not a (singular!) set consisting of multiple individuals as its members. A species is itself an individual consisting of individual organisms as its parts. Any given species is singular, yes, but -- unlike the groups in group selection -- not a singular set.

Took me ages to understand what they were talking about too! Since, on the PE view, species (unlike groups) typically have a fairly well defined beginning (speciation), a long and stable existence (a few million years of stasis), and a well defined end (extinction), they are both real and are individuals.

That is to say, all the dogs (say) that ever were and ever will be, spread all over the planet, not spatially contiguous, nonetheless constitute an individual: namely, the species Canis lupus. Each individual pooch is a part -- not a member -- of that species.

And since they are individuals -- here's the radical part -- they can be selected, thus are actors in the larger drama of evolution (i.e. macroevolution).

Traditional natural selection is still kosher for explaining minor, trivial changes within a species, e.g. dark moths increasing in proportion to light moths. But to explain the larger patterns in evolution -- the big exciting stuff -- natural selection by itself will not do.
 
Last edited:
Notice on the traditional account of evolution -- dare I say The Theory -- species cannot play this role. Species, on this view, are more like colors in a continuous spectrum, not clearly demarcated, and divided up (by ourselves!) somewhat arbitrarily.

On the PE view, by contrast, nature itself decides what a species is.
 
This doesn't seem to add anything new to the idea of pockets of animals isolated from the overall taxonomic group contingently being susceptible to alterations. Drought has been long considered one of the environmental catalysts for change. The "bird song" angle as a focus (and communication methods of organisms in general) is surely already in the repertoire of that area of study, too. But these are the test results, after all, not a prior proposal for stimulating investigation...
- - - - - - - - - - - - - - - - -

Galápagos finches could be singing a different song after repeated drought—one that leads to speciation
https://www.eurekalert.org/news-releases/1060426

PRESS RELEASE: Galápagos finches use their beaks to crush seeds and sing songs, so what happens to their musical trills when their beaks change to respond to new menus available under drought?

Jeffrey Podos and Katie Schroeder found that the song might not remain the same after six cumulative future drought events that would likely reshape the finch beak. The projected changes in male mating songs could be so significant that they provide a pathway for ecological speciation, the researchers suggest.

The researchers tested this idea by digitally modifying male mating songs of Darwin’s medium ground finches (Geospiza fortis) to sound like they might if beaks grew bigger under one, three or six cumulative future drought events. They then tested these “ghost of finches future” songs by playing them back to today’s male finches, as if the singers of the ghost songs were intruding on the males’ territory.

Current males did not show signs of recognizing songs produced after six cumulative future drought events, treating the unseen producers of these songs as if they were no longer mating rivals. The study provides a better idea of how much “ecological change, and matched evolution of beaks and songs, would be required to elevate barriers to reproductive isolation,” the researchers write.
_
 
axocanth said:
Notice on the traditional account of evolution -- dare I say The Theory -- species cannot play this role. Species, on this view, are more like colors in a continuous spectrum, not clearly demarcated, and divided up (by ourselves!) somewhat arbitrarily.

On the PE view, by contrast, nature itself decides what a species is.
Click to expand...
No. (I'm back Scotty)

Again context is everything AND Evolutionary biologists know exactly what they are talking about.

I tried to explain this to Trek.

I am a human, a modern human but I am also an Ape. Now we also agree that we suckle our young so we are also mammals.

There is no conflict.
 
TheVat said:
I would agree to no such thing, my good fellow! Not once have I suckled my young. And yet I remain a mammal man. In spite of all temptations.
Click to expand...
No our mother's did that!

We will agree then that we are Chordates and bid each other good day.
 
You must log in or register to reply here.
Back
Top