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Author Topic:   Stasis and Evolution
Arphy
Member (Idle past 2512 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 31 of 61 (532884)
10-27-2009 4:48 AM
Reply to: Message 28 by Kaichos Man
10-26-2009 10:22 PM


Hi Kaichos Man, good to have you aboard!

I have to disagree with Arphy that if things are evolving then stasis shouldn't happen. I take your point that if the the organism is being successful, then natural selection should hold it in stasis

What I mean is that under Phyletic gradualism stasis shouldn't happen. Stasis is a big componenet of punctuated equalibrium. Although even under this version there are still problems. I guess it would be good to understand what Bluejay's take on stasis and punctuated equalibrium is, otherwise we will just be stabbing in the dark as to what his position might be.
This message is a reply to:
 Message 28 by Kaichos Man, posted 10-26-2009 10:22 PM Kaichos Man has not yet responded

Replies to this message:
 Message 33 by Dr Jack, posted 10-27-2009 5:47 AM Arphy has responded
 Message 46 by Blue Jay, posted 10-27-2009 10:04 AM Arphy has not yet responded

    
Dr Jack
Member (Idle past 185 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


(1)
Message 32 of 61 (532893)
10-27-2009 5:45 AM
Reply to: Message 30 by Otto Tellick
10-27-2009 1:31 AM


Re: Haldane's Dilemma? Gould and Eldridge? What??
(Steven) Gould and (Niles) Eldridge seem to have published a lot together (and singly), so if you're going to cite particular assertions of theirs with particular numeric values, it would really help those of us who try to learn things if you could provide a specific reference -- so please provide the reference you got this from.

Gould did give the 99% figure according to Robert L. Carrol's Patterns and Processes of Verterbrate Evolution. He gives the reference for this as p.84 of:

Gould, S.J. (1982) The meaning of punctuated equilibrium and its role in validating a hierarchical approach to macroevolution. In Perspectives on Evolution, ed. R. Milkman, pp.83-104, Sunderland, Mass.: Sinauer Associated.


This message is a reply to:
 Message 30 by Otto Tellick, posted 10-27-2009 1:31 AM Otto Tellick has acknowledged this reply

  
Dr Jack
Member (Idle past 185 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


(1)
Message 33 of 61 (532894)
10-27-2009 5:47 AM
Reply to: Message 31 by Arphy
10-27-2009 4:48 AM


What I mean is that under Phyletic gradualism stasis shouldn't happen.

Only if you absurdly caraciture it. Darwin talks about statis in The Origin for crying out loud!


This message is a reply to:
 Message 31 by Arphy, posted 10-27-2009 4:48 AM Arphy has responded

Replies to this message:
 Message 34 by Arphy, posted 10-27-2009 6:46 AM Dr Jack has responded

  
Arphy
Member (Idle past 2512 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 34 of 61 (532905)
10-27-2009 6:46 AM
Reply to: Message 33 by Dr Jack
10-27-2009 5:47 AM


Darwin talks about statis in The Origin
Trying to hunt this down. Can you give a quote, or reference?
This message is a reply to:
 Message 33 by Dr Jack, posted 10-27-2009 5:47 AM Dr Jack has responded

Replies to this message:
 Message 35 by Dr Jack, posted 10-27-2009 7:06 AM Arphy has not yet responded
 Message 36 by Modulous, posted 10-27-2009 7:11 AM Arphy has not yet responded
 Message 37 by jacortina, posted 10-27-2009 8:23 AM Arphy has not yet responded

    
Dr Jack
Member (Idle past 185 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


(1)
Message 35 of 61 (532906)
10-27-2009 7:06 AM
Reply to: Message 34 by Arphy
10-27-2009 6:46 AM


Um... that be The Origin of the Species by Charles Darwin? You might have heard of it?
This message is a reply to:
 Message 34 by Arphy, posted 10-27-2009 6:46 AM Arphy has not yet responded

  
Modulous
Member (Idle past 184 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


(2)
Message 36 of 61 (532907)
10-27-2009 7:11 AM
Reply to: Message 34 by Arphy
10-27-2009 6:46 AM


Darwin on punctuated equilibrium
Trying to hunt this down. Can you give a quote, or reference?

Chapter 10, On the Origin of Species (first ed):

quote:
Species of different genera and classes have not changed at the same rate, or in the same degree. In the oldest tertiary beds a few living shells may still be found in the midst of a multitude of extinct forms. Falconer has given a striking instance of a similar fact, in an existing crocodile associated with many strange and lost mammals and reptiles in the sub-Himalayan deposits. The Silurian Lingula differs but little from the living species of this genus; whereas most of the other Silurian Molluscs and all the Crustaceans have changed greatly. The productions of the land seem to change at a quicker rate than those of the sea, of which a striking instance has lately been observed in Switzerland.

and

Chapter 15, same (though I think this particular quote was added in a later edition):

quote:
Only a small portion of the world has been geologically explored. Only organic beings of certain classes can be preserved in a fossil condition, at least in any great number. Many species when once formed never undergo any further change but become extinct without leaving modified descendants; and the periods during which species have undergone modification, though long as measured by years, have probably been short in comparison with the periods during which they retained the same form. It is the dominant and widely ranging species which vary most frequently and vary most, and varieties are often at first local--both causes rendering the discovery of intermediate links in any one formation less likely. Local varieties will not spread into other and distant regions until they are considerably modified and improved; and when they have spread, and are discovered in a geological formation, they appear as if suddenly created there, and will be simply classed as new species

Edited by Modulous, : added note about the later edition


This message is a reply to:
 Message 34 by Arphy, posted 10-27-2009 6:46 AM Arphy has not yet responded

  
jacortina
Member (Idle past 3163 days)
Posts: 64
Joined: 08-07-2009


(1)
Message 37 of 61 (532911)
10-27-2009 8:23 AM
Reply to: Message 34 by Arphy
10-27-2009 6:46 AM


quote:
"But I must here remark that I do not suppose that the process ever goes
on so regularly
as is represented in the diagram, though in itself made
somewhat irregular, nor that it goes on continuously; it is far more
probable that each form remains for long periods unaltered
, and then
again undergoes modification." (pp. 152)

Darwin, C. 1872. "Chapter 4 - Natural Selection" The Origin of Species,
Sixth Edition. The Modern Library, New York.


Bolds are mine. And they pretty clearly point to an expectation by Darwin of stasis/near-stasis as being the norm.


This message is a reply to:
 Message 34 by Arphy, posted 10-27-2009 6:46 AM Arphy has not yet responded

    
Kaichos Man
Member (Idle past 2568 days)
Posts: 250
From: Tasmania, Australia
Joined: 10-03-2009


Message 38 of 61 (532917)
10-27-2009 8:53 AM
Reply to: Message 30 by Otto Tellick
10-27-2009 1:31 AM


Re: Haldane's Dilemma? Gould and Eldridge? What??
I did a quick wikipedia check on Haldane's dilemma

Haldane's Dilemma on Wikipedia is watched over by some troll who instantly changes the entry to a Robert Williams-friendly spiel every time someone tries to edit it.

No matter- Robert Williams is fine- in fact he accepts the figure of 1667 mutations and tries to argue that it is enough. You can google robert williams, but if you have trouble tell me and I'll find the reference.

This has no relation whatsoever to any notion of "stasis" over the life span of organisms within the population of a given species.

Sorry, this was clumsily put. I'm referring to the time span during which a species is in existence, obviously.

In any case, the next time you try to present conclusions based on quantities, you'd better "show your work" (e.g. "1% of 1667 = 17"),

Are you serious? I thought it would be insulting, not courteous!


"Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
This message is a reply to:
 Message 30 by Otto Tellick, posted 10-27-2009 1:31 AM Otto Tellick has acknowledged this reply

    
Kaichos Man
Member (Idle past 2568 days)
Posts: 250
From: Tasmania, Australia
Joined: 10-03-2009


Message 39 of 61 (532918)
10-27-2009 9:09 AM
Reply to: Message 29 by Coyote
10-26-2009 10:51 PM


Likewise, when environmental conditions change quickly, then it is a race against extinction, and most species over many millions of years have lost that race. All living species today are still living exactly because they have won (so far) that race against extinction.

So where's the problem for evolution?

The problem for evolution lies in the fact that if I evolved from a microbe, then every one of my thousands of transitional ancestors must have played -and won- that game of chicken with extinction. And this is true -to a greater or lesser degree- for every creature alive today.

You will no doubt dismiss this as an "argument from incredulity", but remember that even mathematicians have established a working definition of impossibility. It's 1 to 1050. Which is interesting, because Hoyle and Wickramasinge calculated the chance creation of a single living cell as 1 to 1065.


"Often a cold shudder has run through me, and I have asked myself whether I may have not devoted myself to a fantasy." Charles Darwin
This message is a reply to:
 Message 29 by Coyote, posted 10-26-2009 10:51 PM Coyote has not yet responded

Replies to this message:
 Message 41 by bluescat48, posted 10-27-2009 9:30 AM Kaichos Man has responded
 Message 42 by Blue Jay, posted 10-27-2009 9:30 AM Kaichos Man has not yet responded
 Message 43 by Granny Magda, posted 10-27-2009 9:31 AM Kaichos Man has not yet responded
 Message 45 by Parasomnium, posted 10-27-2009 9:56 AM Kaichos Man has responded

    
Blue Jay
Member (Idle past 777 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(2)
Message 40 of 61 (532920)
10-27-2009 9:23 AM
Reply to: Message 27 by Arphy
10-26-2009 3:51 AM


Phase 2: The Problem with "Stasis"
Hi, Arphy.

Welcome.

So, you suggest that stasis is lack of morphological change over millions or billions of years.

Good. Let's run with it.

My next question is why a lack of morphological change over millions of years is a problem. It seems like you're already ready to get into that, so let's get to it.

Arphy writes:

Because if one of the major forces that drives evolution is competition, then lack of change or lack of competitiveness is not helpful in survival of the fittest.

You don't have to win a competition to survive. Probably most of the world's biota survives by avoiding competition, rather than by winning it.

But, again, let's look at the crocodile. What morphological changes are required for the crocodile to retain its niche as a coastal ambush predator?

Does ambushing grazing mammals at a water hole require a different set of adaptations from ambushing comparable dinosaurs at a water hole?
Does waiting at the end of the rapids for modern fish require a different set of adaptations from waiting at the end of rapids for ancient fish?

Perhaps more to the point:
What traits could grazing mammals have evolved that would have helped them avoid being ambushed by crocodiles at water holes?
What could today's fish have evolved that would have helped them avoid crocodiles waiting at the end of rapids?

The point is that some strategies will always be successful enough to persist without major changes. If you want to argue that changes must occur, please explain to me why such changes are needed. And be specific: use my crocodile example.

-----

Arphy writes:

Bluejay writes:

There is no reason to believe that natural selection cannot act on small changes.

e.g. What about "neutral" mutations?

There is also no reason to believe that all small changes are neutral.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 27 by Arphy, posted 10-26-2009 3:51 AM Arphy has not yet responded

  
bluescat48
Member (Idle past 2269 days)
Posts: 2347
From: United States
Joined: 10-06-2007


(1)
Message 41 of 61 (532921)
10-27-2009 9:30 AM
Reply to: Message 39 by Kaichos Man
10-27-2009 9:09 AM


The problem for evolution lies in the fact that if I evolved from a microbe, then every one of my thousands of transitional ancestors must have played -and won- that game of chicken with extinction. And this is true -to a greater or lesser degree- for every creature alive today.

Yes if one assumes that the goal, microbe, X number of steps, human was a directed goal, but since there is no specific goal, then any step would have any given chance of improving survivability for there are 3 possibilities per mutation, harmful, neutral or beneficial thus there is a one in three chance of improving and 2 chances out of three of survival to go one step further.


There is no better love between 2 people than mutual respect for each other WT Young, 2002

Who gave anyone the authority to call me an authority on anything. WT Young, 1969

Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008


This message is a reply to:
 Message 39 by Kaichos Man, posted 10-27-2009 9:09 AM Kaichos Man has responded

Replies to this message:
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Blue Jay
Member (Idle past 777 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(2)
Message 42 of 61 (532922)
10-27-2009 9:30 AM
Reply to: Message 39 by Kaichos Man
10-27-2009 9:09 AM


Hi, Kaichos Man.

Kaichos Man writes:

The problem for evolution lies in the fact that if I evolved from a microbe, then every one of my thousands of transitional ancestors must have played -and won- that game of chicken with extinction. And this is true -to a greater or lesser degree- for every creature alive today.

Three points:

1. I don't see a problem with this.

2. Practically all of my "thousands of transitional ancestors" are the same as your "thousands of transitional ancestors." In fact, most of them are also the same as the "thousands of transitional ancestors" for pronghorn antelopes and mudpuppies, too. So, the situation isn't as dire as you are painting it.

3. What does this have to do with stasis?

-----

Kaichos Man writes:

...mathematicians have established a working definition of impossibility. It's 1 to 1050. Which is interesting, because Hoyle and Wickramasinge calculated the chance creation of a single living cell as 1 to 1065.

Again, three points:

1. Your probabilities fetish is not serving you well.

2. How can you calculate the probability of the occurrence of something if you don't know what's required to make it happen (which we don't know)?

3. What does this have to do with stasis?


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 39 by Kaichos Man, posted 10-27-2009 9:09 AM Kaichos Man has not yet responded

  
Granny Magda
Member
Posts: 2380
From: UK
Joined: 11-12-2007


(2)
Message 43 of 61 (532923)
10-27-2009 9:31 AM
Reply to: Message 39 by Kaichos Man
10-27-2009 9:09 AM


Extinction and Survival
Hi Kaichos Man and since I don't think we've spoken before, welcome to EvC!

The problem for evolution lies in the fact that if I evolved from a microbe, then every one of my thousands of transitional ancestors must have played -and won- that game of chicken with extinction.

That's not quite right.

Extinction isn't something that happens to individuals, it's something that happens to populations, entire species or even larger groups. Whilst each of your ancestors must have won their battle to survive long enough to reproduce, there is absolutely no reason why we should assume that the species to which they belonged should have evaded extinction. An ancestral population could easily go extinct, leaving its derived daughter population, a slightly different species, to continue your ancestral line.

I am at a loss as to how this is supposed to be any kind of objection to the ToE.

Mutate and Survive


"A curious aspect of the theory of evolution is that everybody thinks he understands it." - Jacques Monod
This message is a reply to:
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Blue Jay
Member (Idle past 777 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(2)
Message 44 of 61 (532924)
10-27-2009 9:47 AM
Reply to: Message 28 by Kaichos Man
10-26-2009 10:22 PM


Hi, Kaichos Man.

Kaichos Man writes:

I take your point that if the the organism is being successful, then natural selection should hold it in stasis...

...if stasis indicates success, then phenotypic modification must indicate failure.

You've made two illogical leaps there:

1. That some successful strategies remain in stasis does not mean stasis is an indicator of success.

2. That stasis indicates success does not mean that non-stasis means failure

Remember the gold standard in evolution: survival. It is survival, not stasis, that indicates success.

Stasis merely indicates that the strategy is successful in a broad range of circumstances, so that, even as things change around you, your don't have to change much to adapt to them. But, this doesn't mean that those animals who are changing are not successful: remember, their lineages have survived just as long as the static lineage has, so they must be doing something right, yeah?

-----

Kaichos Man writes:

The second problem is that vast amounts of time spent in stasis greatly reduce the time available to evolve.

Stasis indicates that change has not been necessary for survival in the past, so what makes you believe it will be required in the future? I'm not saying that it won't be required (because there are probably situations in which it will be required), but I am saying that this is not a problem for evolution.

-----

Kaichos Man writes:

I believe Gould and Eldredge suggested that most organisms spend 99% of their life span in stasis. That would mean man would have to evolve from the common ancestor in just 17 mutations!

I would argue that, evolutionarily speaking, all organisms spend 100% of their lifespan in stasis.

Individual organisms do not evolve.

-----

Kaichos Man writes:

Stasis is obvious from the fossil record. It is observed and documented.

Agreed. I would add that gradualism is also obvious from the fossil record; and that it is also observed and documented.

-----

Kaichos Man writes:

Its [Stasis's] ramifications for the ToE are that evolution has very little time to bring about phenotypic change, and can only do so while playing "chicken" with extinction.

Your gift for anthropomorphization is limitless.

Naturally, I argue that not all evolutionary pressures have to be dramatic, extinction-level cataclysms. Evolution "innovation" can also come about by gradual, subtle changes in fitness due to random mutations.


-Bluejay (a.k.a. Mantis, Thylacosmilus)

Darwin loves you.


This message is a reply to:
 Message 28 by Kaichos Man, posted 10-26-2009 10:22 PM Kaichos Man has not yet responded

  
Parasomnium
Member (Idle past 776 days)
Posts: 2191
Joined: 07-15-2003


(2)
Message 45 of 61 (532926)
10-27-2009 9:56 AM
Reply to: Message 39 by Kaichos Man
10-27-2009 9:09 AM


Someone must win
Kaichos Man writes:

even mathematicians have established a working definition of impossibility. It's 1 to 1050.

Clearly something with a chance of 1 in 1050 or less is still possible: the total result of two hundred coin flips in a row has a chance of about 1 in 1.6 x 1060, and I think you'll agree that it's a matter of minutes to flip a coin two hundred times. Whatever the outcome, it had a chance of 1 in 1.6 x 1060. Yet it happened.

Now, if you had predicted this particular outcome, that would have been something so unlikely as to be well-nigh impossible. And it's this element of prediction that's missing from the story of evolution.

The chance of someone emerging as victorious from Wimbledon is 1. This person has won each and every tennis match they played during the tournament. Amazing? No, because someone must be the victor. But it's much more unlikely to correctly predict the victor.

Edited by Parasomnium, : No reason given.

Edited by Parasomnium, : No reason given.


"Ignorance more frequently begets confidence than does knowledge: it is those who know little, not those who know much, who so positively assert that this or that problem will never be solved by science." - Charles Darwin.
This message is a reply to:
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Replies to this message:
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