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Author Topic:   Stasis and Evolution
Blue Jay
Member (Idle past 778 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 46 of 61 (532927)
10-27-2009 10:04 AM
Reply to: Message 31 by Arphy
10-27-2009 4:48 AM


Phase 2: The problem with Stasis
Hi, Arphy.

Arphy writes:

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.

Once again, we're not talking about Bluejay's take on stasis or punctuated equilibrium. Your beef is with evolutionary biology, not with Bluejay: you obviously didn't need to know my opinion before you took a stance on this issue, so why do you need to know now?

Furthermore, given how you ignored the substance of my arguments in another thread in order to pursue a clumsy psychoanalysis of me and my religious beliefs, I feel no motivation whatsoever to reveal anything about myself to you. It would only distract you from the topic I actually want to discuss.

We're only talking about why you think stasis is a problem for evolutionary biology. That means that, for the sake of this debate, we are assuming that there is stasis in the fossil record, and we are trying to show whether this can be used as evidence against evolution.


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

Darwin loves you.


This message is a reply to:
 Message 31 by Arphy, posted 10-27-2009 4:48 AM Arphy has not yet responded

  
Theodoric
Member
Posts: 5954
From: Northwest, WI, USA
Joined: 08-15-2005
Member Rating: 2.8


Message 47 of 61 (532932)
10-27-2009 10:40 AM
Reply to: Message 22 by Arphy
10-17-2009 1:35 AM


Not an authority of any type
from creationist author "John Woodmorappe," a high school teacher
who happens to have a BA in Biology, a BA in Geology, and an MA in Geology.

This does not make him any sort of authority. By the way, do you realize that this is a pen name. There is no way we can even confirm his credentials because he won't even use his real name. He could claim anything and non one could confirm or deny it since he won't use his real name.

quote:
John Woodmorappe (born October 1954) is the pen name of an author who has published several articles and books with the creation science groups Answers in Genesis and the Institute for Creation Research. His main works are Noah's Ark: A Feasibility Study and the The Mythology of Modern Dating Methods. He has also written several articles in creationist journals.
Source

If his work is so great how come he doesn't publish in real scientific journals?


Facts don't lie or have an agenda. Facts are just facts
This message is a reply to:
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Replies to this message:
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Coyote
Member (Idle past 186 days)
Posts: 6117
Joined: 01-12-2008


(2)
Message 48 of 61 (532937)
10-27-2009 11:56 AM
Reply to: Message 47 by Theodoric
10-27-2009 10:40 AM


Re: Not an authority of any type
If his work is so great how come he [John Woodmorappe] doesn't publish in real scientific journals?

Because he writes things like:

quote:
The relevant evidence clearly shows that Homo sapiens sensu lato is a separate and distinct entity from the other hominids. No overall evolutionary progression is to be found. Adam and Eve, and not the australopiths/habilines, are our actual ancestors. As pointed out by other creationists [e.g., Lubenow], Homo ergaster, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis can best be understood as racial variants of modern man–all descended from Adam and Eve, and most likely arising after the separation of people groups after Babel.

http://www.answersingenesis.org/tj/v13/i2/human_fossils.asp


No reputable scientific journal would touch that steaming pile with a ten foot pole.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
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RAZD
Member
Posts: 19759
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 6.4


(2)
Message 49 of 61 (532984)
10-27-2009 8:16 PM
Reply to: Message 27 by Arphy
10-26-2009 3:51 AM


Re: Phase 1: Defining "Stasis"
Hi Arphy,

Which of these types of change, in your mind, count as significant change?
Morphological. In other words the problem is that the basic organism remains the same even though that morphologically similar version of the organism should have become extinct and have evolved into something else.

There is no dictum that organisms must change, evolution is a response feedback system. When there are changes in the ecology the population is under pressure to adapt to the changes or perish, when there are no changes there is no pressure to change.

First, let's look at what constitutes a level of change to move out of stasis. You seem to have a picture in your mind of a certain amount of change, but are having some trouble with categorizing it, developing a metric to determine it. I have tried to develop a discussion on the topic of how large a difference is large enough on the Dogs will be Dogs wil be ??? thread. Note that biologists don't care how big (or small) the change is once speciation has occurred.

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.

Competition for resources yes - more so when the resources are limited, but not so much when opportunities to use new resources are available, as this changes the competition matrix. When one variety can make better use of a new resource/s than another variety, then it will be more successful in that new ecology leaving the old version behind in the previous ecology to which it is well adapted.

Rather than survival of the fittest, one should consider the survival of those able to survive, as any organism barely able to survive and reproduce has met the minimal requirements of evolution to proceed.

Here's an example of a speciation event in the fossil record:

http://www.mun.ca/biology/scarr/Pelycodus_gradual.htm

quote:

Here you can see the general evolution of this population of organisms increasing in size from bottom (oldest) to top (youngest) and three attempts to branch off, the first two becoming extinct as there is apparently not enough ecological difference between parent population and the daughter population to support both populations. The third population, however, succeeds, with sufficient ecological difference to support the smaller daughter branch on the right side and the larger main population branch on the left side. The large sized organisms move into new ecological opportunities that the smaller branch is not as able to take advantage of, while leaving the opportunities of the old ecology to the smaller population that the larger ones are not as able to take advantage of.

When we look at the main branch we could call that stasis, as the organisms are morphologically similar, albeit of different overall size. This is the same kind of difference between modern Coelacanths and ancient ones. But when we compare it to the other branch we see that change in size is important to the whole picture of adaptation to the ecology, and does not really qualify as stasis. Neither of these branches demonstrate stasis in the fossil record.

Both are fit for their new ecologies, but it is the ecological opportunities that are different and that drive the changes seen

For this debate, by vast periods of time I mean anything from a few million years to a few billion years.

The branching diagram above covers about 5 million years.

Personally I would agree that competition between daughter species in nearby, overlapping, or especially in the same areas (as appears to be the case here) would drive any sexually isolated daughter populations to move away from the parent, or another daughter, population ecology into separated ecologies as fast as possible to enhance their survival options. In this case one population continues to get bigger - to concentrate on opportunities their larger size affords - while the other rapidly gets smaller, reverting to the more distant ancestral size - to concentrate on the opportunities their smaller size affords. Think treetop versus forest floor.

This is one of the reasons that the rates of evolution will almost inevitably vary when new species first evolve, compared to the rate of evolution once they have become well established in a stable ecology.

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.

Now consider that where we have a static ecology, and therefore no pressure to change nor any opportunity to take advantage of new ecologies, that the competition will be to remain as well adapted as the ancestral population were: the small changes that tend to diverge from the parent population are not as successful at surviving and reproducing, so stasis is selected to match the static ecology.

e.g. What about "neutral" mutations?

By definition "neutral" mutations are ones that do not effect the selection process. This could involve fur patterns, eye color, size, etc etc around the normal values, and would show up as gradual change over even longer periods of time due to genetic drift and chance factors (killed by natural cause, tree falling etc) that are not selection factors.

Enjoy.

Edited by RAZD, : clrty


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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

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


Message 50 of 61 (533142)
10-29-2009 1:48 AM
Reply to: Message 45 by Parasomnium
10-27-2009 9:56 AM


Re: Someone must win
Nice avatar! I won't say anything unseemly in case its your daughter.

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.

The chance of the coin being flipped 200 times is 1. The probability of any given result is irrelevant unless it is specified. It is the same with the creation of a 1000 bp gene. The chance of 1000 base pairs existing is 1. The chance of them creating a gene that produces an enzyme (assuming there are about 20,000 possible enzymes) is 20,000 divided by 41000. Which makes it a stone cold certainty that they will create nothing at all.


"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:
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Replies to this message:
 Message 52 by cavediver, posted 10-29-2009 4:22 AM Kaichos Man has responded
 Message 54 by Blue Jay, posted 10-29-2009 11:06 AM Kaichos Man has responded
 Message 58 by Dr Jack, posted 11-05-2009 10:19 AM Kaichos Man has not yet responded

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


Message 51 of 61 (533143)
10-29-2009 1:57 AM
Reply to: Message 41 by bluescat48
10-27-2009 9:30 AM


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.

Only if harmful, neutral and beneficial mutations occurred equally. The observation is that for every 175 mutations there are 3 deleterious, the other 172 being neutral or nearly neutral. Beneficial mutations are too rare, according to geneticist Motoo Kimura, to enter into calculations.


"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:
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cavediver
Member (Idle past 1723 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 52 of 61 (533152)
10-29-2009 4:22 AM
Reply to: Message 50 by Kaichos Man
10-29-2009 1:48 AM


Re: Someone must win
The chance of them creating a gene that produces an enzyme (assuming there are about 20,000 possible enzymes) is 20,000 divided by 41000.

Really? So what do all the other combinations produce? Nothing at all? Does the ribosome somehow look at the entire 1000 bp and think, "huh, that makes no sense" and goes elsewhere


This message is a reply to:
 Message 50 by Kaichos Man, posted 10-29-2009 1:48 AM Kaichos Man has responded

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


Message 53 of 61 (533184)
10-29-2009 8:03 AM
Reply to: Message 52 by cavediver
10-29-2009 4:22 AM


Re: Someone must win
Really? So what do all the other combinations produce? Nothing at all?

Not an enzyme. And I think you'd agree that for evolution from microbe to man to be possible, the odd enzyme would need to come into being.

And the probabilities show that that is marginally more probable than a talking ribosome


"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:
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Blue Jay
Member (Idle past 778 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 54 of 61 (533204)
10-29-2009 11:06 AM
Reply to: Message 50 by Kaichos Man
10-29-2009 1:48 AM


Re: Someone must win
Hi, Kaichos Man

Kaichos Man writes:

The probability of any given result is irrelevant unless it is specified.

And, since evolution does not specify its results, your probability argument is irrelevant, right?

Well, it certainly is irrelevant to this topic: stop discussing it here!


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

Darwin loves you.


This message is a reply to:
 Message 50 by Kaichos Man, posted 10-29-2009 1:48 AM Kaichos Man has responded

Replies to this message:
 Message 55 by Kaichos Man, posted 10-31-2009 8:42 AM Blue Jay has not yet responded

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


Message 55 of 61 (533483)
10-31-2009 8:42 AM
Reply to: Message 54 by Blue Jay
10-29-2009 11:06 AM


Re: Someone must win
Well, it certainly is irrelevant to this topic: stop discussing it here!

Alright. (Sulking) But I didn't start it...


"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:
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MarkAustin
Member (Idle past 1895 days)
Posts: 122
From: London., UK
Joined: 05-23-2003


(3)
Message 56 of 61 (533569)
11-01-2009 5:35 AM


Statis and Gradualism
I'd like to make a general comment on statis and gradualism in evolution.

One of the problems in discussing evolution today is the earlier insistence om gradualism seems to creationists to mean that evidence of stsis is evidence against evolution.

As has been said Darwin in "The Origin of the Species" discusses statis, but in much argument early proponents of evolution stressed gradualism.

The reason for this is rooted in the beliefs and theories of the time.

Contrary to popular belief, Darwin's contribution to evolutionary theory was not evolution itself but the mechanism of evolution: Natural Selection.

Amongst scientific circles in Darwin's time, the idea of evolution - that is, at its most basic, the change of species over time - was accepted generaly as a working model. Although the fossil record was very incomplete compared to today, enough was known to be sure that organisms in the past were highly different from the present.

The problem was the mechanism. At the time, most favoured a saltationist approach: the sudden appearance of new species (either naturally or by special creation) and a catastrophic approach to geology: by this time multiple catastrphism, not just the Biblical flood, which was viewed by many as the last in a series.

Hence, in argung for Darwin's gradualist approach (and the similar gradualist approach in geology), the arguments de-emphasised the statist feature of evolution (and the occasional catastrophic event in geology) in order to win the basic argument: that most changes are gradualist.

The consequence of this today is that arguments for statis in evolution (and catastrophism in geology) seem to produce argument against evolution. It is important to note that not only are these arguments fallacious, but they were not held, in the simplistic form, by the originators of evolutionary theory.


For Whigs admit no force but argument.
    
Parasomnium
Member (Idle past 776 days)
Posts: 2191
Joined: 07-15-2003


(1)
Message 57 of 61 (533578)
11-01-2009 9:23 AM
Reply to: Message 55 by Kaichos Man
10-31-2009 8:42 AM


Re: Someone must win
Well, it certainly is irrelevant to this topic: stop discussing it here!

Alright. (Sulking) But I didn't start it...

No, I did. I am sorry for going off-topic.


This message is a reply to:
 Message 55 by Kaichos Man, posted 10-31-2009 8:42 AM Kaichos Man has not yet responded

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


(1)
Message 58 of 61 (534148)
11-05-2009 10:19 AM
Reply to: Message 50 by Kaichos Man
10-29-2009 1:48 AM


Re: Someone must win
assuming there are about 20,000 possible enzymes

STOP MAKING UP NUMBERS


This message is a reply to:
 Message 50 by Kaichos Man, posted 10-29-2009 1:48 AM Kaichos Man has not yet responded

  
RAZD
Member
Posts: 19759
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 6.4


(1)
Message 59 of 61 (534508)
11-08-2009 9:48 PM
Reply to: Message 15 by caffeine
10-14-2009 5:21 AM


Re: Stasis in naturally adaptable organisms
Hi caffeine, I've been thinking about this for a while.

Something that Bluejay said when writing about rats made me think about evolutionary stasis in omnivorous animals capable of surviving on a variety of foodstuffs, that are very behaviourally adaptable already. In such a species, wouldn't it be a stable, unchanging environment that actually selected for change?

I think that would have to be a very stable ecology. Ultimately I think that genetic drift would change any species that is that adapted to so many ecologies that it can survive equally well in many of them.

I think of 50 Starlings, intentionally introduced in 1890 and now universal pests across america as an example.

See Differential Dispersal Of Introduced Species - An Aspect of Punctuated Equilibrium for more.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
 Message 15 by caffeine, posted 10-14-2009 5:21 AM caffeine has responded

Replies to this message:
 Message 60 by caffeine, posted 11-11-2009 8:54 AM RAZD has responded

  
caffeine
Member
Posts: 1602
From: Prague, Czech Republic
Joined: 10-22-2008
Member Rating: 2.5


(1)
Message 60 of 61 (534829)
11-11-2009 8:54 AM
Reply to: Message 59 by RAZD
11-08-2009 9:48 PM


Re: Stasis in naturally adaptable organisms
Sorry RAZD, I'm not quite sure I grasp the point you're making with the starlings. They're adaptable animals that have taken up home in all sorts of habitats across the Americas in a very quick timespan, but this doesn't seem to tell us much about whether they'd trade their adaptability for specialisation if stuck in an unchanging environment for tens or hundreds of thousands of years.
This message is a reply to:
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