Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 80 (8863 total)
Current session began: 
Page Loaded: 09-19-2018 9:01 AM
216 online now:
kjsimons, PaulK, Percy (Admin), Phat (AdminPhat), Tangle (5 members, 211 visitors)
Chatting now:  Chat room empty
Newest Member: rldawnca
Happy Birthday: AdminPhat
Post Volume:
Total: 838,662 Year: 13,485/29,783 Month: 931/1,576 Week: 143/303 Day: 3/31 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Prev1
2
345Next
Author Topic:   Stasis and Evolution
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 16 of 61 (530596)
10-14-2009 6:51 AM
Reply to: Message 1 by Blue Jay
10-05-2009 11:17 AM


Hi Bluejay

First just have to mention that, that ACD is quite a character, very amusing. A bit crazy, but also very amusing and some surprisingly good points (although no doubt you'll disagree with that last bit).
Anyway.

First of all, do you believe that stasis exists? In the first post of this thread you suggest that you do however in your reply to me in the other thread you say

So I ask you, how is it that you think the fossil record shows stasis, when it actually shows rapid turnover of species in a period of just a few million years? This is not stasis: this is change over time.
So which is it?

So again i ask, are you saying that stasis is proof of evolution, or that stasis is consistent with evolution?
I find it somewhat inconsistent to say that no significant change over time = proof for significant change over time. That just doesn't make any sense. If you believe that stasis is consistent with the evolutionary story then sure, lets discuss that.

Again do you really think that an environment can stay that consistent for such long periods of time? It is all very fine to say "oh, it was only a few million years" but i think that evolutionists have somehow become so used to millions of years that they have lost sight of the fact that a million years is a very, very, very long period of time. Also another point to make is that while these organisms remain in stasis other organisms around them are supposedly constantly evolving through competition and natural selection. Why are these animals immune to competition from other organisms? As an analogy, in business a company should always seek to be improving, being on "the cutting edge", innovative, etc. in order to survive. If a company just remains doing the same old thing then they will eventually fail and be succeeded by a more innovative company. So what i am saying that just because the physical environment might not change this doesn't mean that competition stops.

So, in summary, my position is that Arphy’s view (that stasis should not happen if things evolve) comes from an oversimplified understanding of evolution, and of the processes and functions of life.
Not sure how your comments in your post refuted "that stasis should not happen if things evolve". hmm..???

The replys to my quote in the initial message from http://creation.com/images/pdfs/tj/j18_1/j18_1_48-51.pdf seemed a bit contradictory:

dwise writes:

Why? Punc Eq makes an enormous amount of sense. And, to be honest, I'm sure that most "evos" here agree with it to some extane and do not see it as a minority view.

mrjack writes:

There have now been several decades of study into punctuated equilibrium, and the the predominant finding is that it represents a misreading of the geological record.

so which is it?

Anyway here is the quote again.

Chapter nine, ‘Punctuated Equilibrium and the Validation of Macroevolutionary Theory’ is a Trojan horse for creationists. Although unintended, in this chapter Gould provides a completely updated and superbly annotated treasure trove (almost three hundred pages) for creationists to foil arguments from any scientist who claims that there is ample evidence for gradualism in the fossil record. On the lack of change in the fossil record Gould states:
‘ … the tale itself illustrates the central fact of the fossil record so well—[the] geologically abrupt origin and subsequent extended stasis of most species … Anatomy may fluctuate through time, but the last remnants of a species look pretty much like the first representatives’ (p. 749).

Quoting none other than George Gaylord Simpson (p. 755):

‘ … the greatest and most biologically astute paleontologist of the 20th century … acknowledged the literal appearance of stasis and geologically abrupt origin as the outstanding general fact of the fossil record and as a pattern which would “pose one of the most important theoretical problems in the whole history of life”’ (p. 755) [emphasis added].

Gould provides additional creationist evidence stating:

‘The long term stasis following a geologically abrupt origin of most fossil morphospecies, has always been recognized by professional paleontologists’ (p. 752).

‘The great majority of species do not show any appreciable evolutionary change at all. These species appear in the section (first occurrence) without obvious ancestors in underlying beds, are stable once established and disappear higher up without leaving any descendants’ (p. 753).

Gould provides additional testimony for predominant stasis in numerous species, and to eliminate any possibility of confusion he hammers on with ‘…but stasis is data’, and ‘Say it ten times before breakfast every day for a week, and the argument will surely seep in by osmosis: “stasis is data; stasis is data” …’ (p. 759).

Gould then debunks the ‘ … exceedingly few cases that became textbook "classics” of the coiling of Gryphaea and the increasing body size of horses etc. … (p. 760). (Interestingly, nearly all these ‘classics’ have since been disproved, thus providing another testimony for the temporary triumph of hope and expectation over evidence).’

He continues:

‘Indeed proclamations for the supposed “truth” of gradualism—asserted against every working paleontologist’s knowledge of its rarity—emerged largely from such a restriction of attention to exceedingly rare cases under the false belief that they alone provided a record of evolution at all! The falsification of most “textbook classics” upon restudy only accentuates the fallacy of the “case study” method and its root in prior expectation rather than objective
reading of the fossil record’ (p. 773).

Also for anyone jumping into this debate have a read through my original post over here and the replies to see if there is a particularly good point that you want to reintroduce here.

Thanks


This message is a reply to:
 Message 1 by Blue Jay, posted 10-05-2009 11:17 AM Blue Jay has responded

Replies to this message:
 Message 17 by Blue Jay, posted 10-14-2009 11:30 AM Arphy has responded

    
Blue Jay
Member (Idle past 590 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 17 of 61 (530636)
10-14-2009 11:30 AM
Reply to: Message 16 by Arphy
10-14-2009 6:51 AM


Phase 1: Defining "Stasis"
Hi, Arphy

Good to hear from you.

Let’s ignore, for the moment, what my personal opinion about stasis is, and focus on the evidence in the fossil record and the logical implications of the Theory of Evolution about stasis.

The first thing we need to do is establish what is meant by “stasis.” It wasn’t particularly clear in the other thread, but we could (and, in that thread, actually did) define stasis in two different ways:

  1. Persistence of a species across the fossil record (“phylogenetic stasis”).
  2. Persistence of a morphological form or feature across the fossil record (“morphological stasis”).

We do not see the first type of stasis: we see a species persisting across maybe 10 million years' worth of geological strata, only to be replaced by a new species.
However, we do see the second type: many organisms show very little gross morphological change over time.

The confusion over stasis comes in when someone like Calypsis4 sees morphological stasis, and treats it as if it were phylogenetic stasis. For instance, a Jurassic scorpionfly is similar to a modern scorpionfly in gross morphology. However, closer examination of, for instance, the wing venation shows that the Jurassic species is distinct from all living species (and from all species that have existed between then and now).

This is clear evidence of change over time, isn’t it?

So, the debate must only be about how much change occurs over time, right?

This is where my primer in the OP comes in. It becomes important to establish how much change should occur under the Theory of Evolution.

The first step in that process is for us to determine what causes evolutionary change. Once we have established an agreed-upon suite of causes, then we can determine a reasonable expectation for the amount of change (and the variance in that amount) that should happen due to those causes.

I have presented an argument that evolutionary change is due to a whole plethora of different mechanisms that are expressed differently in different situations, and that we thus shouldn’t expect all things to show the same degree and type of change over the same period of time.

Do you accept this argument?

-----

Once you have provided a commentary on this, we can proceed to discuss the range of different rates that could theoretically be seen, and determine whether long-lasting morphological stasis is plausible.

Because Punctuated Equilibrium deals with variance in the rate of change, and we haven't even agreed upon an acceptable range for that rate yet... let's leave punctuated equilibrium out for now. But, I'm sure we'll get to it before too long, anyway.

Edited by Bluejay, : added "only to be replaced by a new species"


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

Darwin loves you.


This message is a reply to:
 Message 16 by Arphy, posted 10-14-2009 6:51 AM Arphy has responded

Replies to this message:
 Message 18 by Arphy, posted 10-16-2009 10:24 PM Blue Jay has responded

  
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 18 of 61 (531302)
10-16-2009 10:24 PM
Reply to: Message 17 by Blue Jay
10-14-2009 11:30 AM


Re: Phase 1: Defining "Stasis"
Hi Bluejay, nice new avatar.

So you want me to produce a fossil and a living organism that have the same species name? Unfortunatly species are often named differently just because they are found in different places in the fossil record, or for some other reason like that (e.g. see http://www.nature.com/news/2008/08091.../news.2008.1111.html). So I guess we could discuss if some of the new species classifications are justified.
Also it is important to note that YECs believe that most of the fossils we have in the fossil record originated in the flood. This means that in some cases there would have been quite an extreme bottleneck effect as a representative species from a kind was taken onto the ark, which then rapidly diversified after the flood, so really we are talking about relatively constant stasis.

This is clear evidence of change over time, isn’t it?

Yip

So, the debate must only be about how much change occurs over time, right?
hmmm.... sort of, but not really. First again note that the debate about change is not necessarily how much but rather what type of change. What you discussed in your OP, namely that change happens in two ways, mutation and natural selection, and these two concepts can be worked out in nature in many different ways, I agree with, so the answer is yes to your question:
Do you accept this argument?
however, that is because the difference in creation and evolution is in terms of genetic entropy, increase in information, and the timespan taken for changes (?). This discussion is about whether or not evolution can account for only very minor changes (of any type) over millions of years in species (so the timespan part). Note that in the creation model there are far less catastrophic changes in environment (basically the flood and the following Ice age are the main two) than in the evolution model. How did these organisms stay more or less the same over those vast periods of time even through many drastic changes? i.e.
‘Of great interest to paleontologists and evolutionary biologists alike is the occurrence of relict or holdover
faunas, also known as Lazarus taxa. These taxa, mostly at family,
genus, and species levels, appear to leapfrog large intervals of geologic time, including the recovery phases
following mass extinctions. They seem to elude our most concerted
sampling efforts, failing to be accounted for over considerable
intervals of time.’
Quote found here creation.com/images/pdfs/tj/j14_1/j14_1_07-08.pdf can't seem to find original article from which the quote is taken on the web.

If you wanted to give the topic a bit of a twist i guess you could possibly try to argue that organisms show too much stasis for the creation - diversification - flood - regeneration/diversification model as well .

hmm...Don't know if i explained the stuff above that well, but we'll see.


This message is a reply to:
 Message 17 by Blue Jay, posted 10-14-2009 11:30 AM Blue Jay has responded

Replies to this message:
 Message 19 by Coyote, posted 10-16-2009 11:02 PM Arphy has responded
 Message 23 by Blue Jay, posted 10-17-2009 2:11 AM Arphy has responded

    
Coyote
Member
Posts: 6117
Joined: 01-12-2008


(1)
Message 19 of 61 (531307)
10-16-2009 11:02 PM
Reply to: Message 18 by Arphy
10-16-2009 10:24 PM


Re: Phase 1: Defining "Stasis"
Also it is important to note that YECs believe that most of the fossils we have in the fossil record originated in the flood. This means that in some cases there would have been quite an extreme bottleneck effect as a representative species from a kind was taken onto the ark, which then rapidly diversified after the flood, so really we are talking about relatively constant stasis.

Nope.

You are talking about evolution at several hundred times the rate proposed by paleontologists.

Lets just take the case for modern man vs. earlier species.

Creationist author "John Woodmorappe" writes:

...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. (Source)

So what you have here is the exact evolution proposed by paleontologists, which they suggest occurred over a period of about two million years, being crammed into the time from Babel to the advent accurate historic records. What creationists are doing is showing paleontologists are correct about the ability of evolution to enact change, but in this case creationists are going them one better: they are proposing the exact same evolution at a rate several hundred times faster and in reverse!

Note that in the creation model there are far less catastrophic changes in environment (basically the flood and the following Ice age are the main two) than in the evolution model. How did these organisms stay more or less the same over those vast periods of time even through many drastic changes?

Your suggested dates are contrary to all empirical evidence. First, there is no empirical evidence for a global flood ca. 4,350 years ago (the data suggested by biblical scholars). Second, there is absolutely no evidence of an ice age after that date (since 4,350 years ago). Rather, there is evidence for a lot of ice ages earlier than that date. The most recent began to wane some 15,000 years ago.

Try again with more reference to empirical evidence and less reference to creation mythology?

Once we get the dating straightened out we can deal with stasis, eh?


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
 Message 18 by Arphy, posted 10-16-2009 10:24 PM Arphy has responded

Replies to this message:
 Message 20 by Arphy, posted 10-17-2009 12:10 AM Coyote has responded

  
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 20 of 61 (531316)
10-17-2009 12:10 AM
Reply to: Message 19 by Coyote
10-16-2009 11:02 PM


Re: Phase 1: Defining "Stasis"
in reverse

YES!!

at a rate several hundred times faster

YES!! That is because we have real live evidence that speciation is rapid! This from a footnote in http://creation.com/speedy-species-surprise

Evolutionists have invented a unit called the ‘darwin’ for measuring the speed of change in the form (body size, leg length, etc.) of a species. In the case of the Anolis sagrei lizards, the rate of change ranged up to 2,117 darwins—whereas evolutionists had only ‘measured’ rates of 0.1 to 1.0 darwins over the ‘millions of years in the fossil record’. For the guppies in Trinidad, the rates were even higher: from 3,700 to 45,000 darwins. Artificial selection experiments on laboratory mice show rates of up to 200,000 darwins.

This message is a reply to:
 Message 19 by Coyote, posted 10-16-2009 11:02 PM Coyote has responded

Replies to this message:
 Message 21 by Coyote, posted 10-17-2009 12:29 AM Arphy has responded

    
Coyote
Member
Posts: 6117
Joined: 01-12-2008


(1)
Message 21 of 61 (531318)
10-17-2009 12:29 AM
Reply to: Message 20 by Arphy
10-17-2009 12:10 AM


Re: Phase 1: Defining "Stasis"
Arphy, you have got to be kidding me.

Creationists spend most of their time arguing against the theory of evolution (of which speciation is the keystone) rather than supporting either creationism or intelligent design.

I presented in my post a scenario (from creationist author "John Woodmorappe," a high school teacher) who proposes a rate for evolution that is several hundred times faster than that proposed by paleontologists--and in reverse!

And you agree with it! You post: "That is because we have real live evidence that speciation is rapid!"

You can't have it both ways.

If you are all in favor of speciation (because you need to explain the extremely rapid diversification of species after the ark grounded in order to keep the number of "kinds" on the ark to a minimum), then you can't complain about paleontologists who see a much slower rate of speciation as a part of evolution.

You don't get to pick and choose the results you like because of your religious beliefs. If you are going to pretend to follow the scientific method, then you have to follow it! Even if it leads to conclusions you don't like.

Otherwise you are doing religious apologetics, not science.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
 Message 20 by Arphy, posted 10-17-2009 12:10 AM Arphy has responded

Replies to this message:
 Message 22 by Arphy, posted 10-17-2009 1:35 AM Coyote has not yet responded

  
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 22 of 61 (531323)
10-17-2009 1:35 AM
Reply to: Message 21 by Coyote
10-17-2009 12:29 AM


Re: Phase 1: Defining "Stasis"
the theory of evolution (of which speciation is the keystone)
and is also a key component in the creation model.

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.

because you need to explain the extremely rapid diversification of species after the ark grounded in order to keep the number of "kinds" on the ark to a minimum
After the flood it is quite natural to deducte that obviously there was basically no competition for the surviours. Generally no competition leads to exponential growth and also allows organisms to adapt to new and varied habitats quickly, as seen today.

then you can't complain about paleontologists who see a much slower rate of speciation as a part of evolution.
Umm... why not? Rapid speciation is a directly observable phenomenon. Slow speciation isn't.

You don't get to pick and choose the results you like because of your religious beliefs. If you are going to pretend to follow the scientific method, then you have to follow it! Even if it leads to conclusions you don't like.
And creationists don't? Take for example the horse series. As shown in previous posts it seems that evolutionists have been right about the relatedness of these species even when a creationist approach was taken. No we are not going to throw the baby out with the bathwater, so to speak, when it comes to evolutionist research, but we do take it with a grain of salt, so to speak. I would also hope that by now you would have realised that creationists would say exactly the same thing (your quote directly above) to evolutionists as well regarding where the evidence leads.
This message is a reply to:
 Message 21 by Coyote, posted 10-17-2009 12:29 AM Coyote has not yet responded

Replies to this message:
 Message 24 by Blue Jay, posted 10-17-2009 2:21 AM Arphy has not yet responded
 Message 47 by Theodoric, posted 10-27-2009 10:40 AM Arphy has not yet responded

    
Blue Jay
Member (Idle past 590 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 23 of 61 (531324)
10-17-2009 2:11 AM
Reply to: Message 18 by Arphy
10-16-2009 10:24 PM


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

Thanks for the response.

Arphy writes:

So you want me to produce a fossil and a living organism that have the same species name?

No: I merely want to know if what you think of as "stasis" is the same as what I think of as "stasis."

I can think of two pro-creationist arguments that you might be making with this "stasis" angle:

  1. Lack of large changes over time shows that microevolution can happen, but not macroevolution.
  2. The only changes we see in the fossil record are the emergence of new species, which suggests de novo creation, not gradual change over time.

Since I don't know which of these angles you want to take yet, I thought it prudent to determine what it is you think "stasis" means, and thereby determine what kinf o argument I might need to deal with.

We don't have to take the entire debate in one post.

-----

Arphy writes:

Unfortunatly species are often named differently just because they are found in different places in the fossil record...

I'm quite certain that this is incorrect (and the article you cited doesn't say anything about it, either). It may happen, for sure, but I very strongly doubt that it happens often.

-----

Arphy writes:

First again note that the debate about change is not necessarily how much but rather what type of change.

So, can you provide me with some objective criteria whereby you judge which types of change are possible and which types are not? I suspect that "types of change," in the end, will still end up being "amounts of change," anyway.


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

Darwin loves you.


This message is a reply to:
 Message 18 by Arphy, posted 10-16-2009 10:24 PM Arphy has responded

Replies to this message:
 Message 25 by Arphy, posted 10-17-2009 7:54 AM Blue Jay has responded

  
Blue Jay
Member (Idle past 590 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 24 of 61 (531325)
10-17-2009 2:21 AM
Reply to: Message 22 by Arphy
10-17-2009 1:35 AM


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

Arphy writes:

Rapid speciation is a directly observable phenomenon. Slow speciation isn't.

If it can happen rapidly, why can't it happen slowly?

-----

Arphy writes:

No we are not going to throw the baby out with the bathwater, so to speak, when it comes to evolutionist research, but we do take it with a grain of salt, so to speak.

You should take all arguments with a grain of salt.


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

Darwin loves you.


This message is a reply to:
 Message 22 by Arphy, posted 10-17-2009 1:35 AM Arphy has not yet responded

  
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 25 of 61 (531351)
10-17-2009 7:54 AM
Reply to: Message 23 by Blue Jay
10-17-2009 2:11 AM


Re: Phase 1: Defining "Stasis"
I am arguing that a lack of significant change in the morphology of organisms over vast periods of time is not compatible with the general evolutionary framework.

I'm quite certain that this is incorrect (and the article you cited doesn't say anything about it, either).
yeah, the article abstract doesn't say anything directly about fossils that are named because of stratigraphic location, would need to check with the full article. But then again i gave this link as more of a reference for my comment
arphy writes:

or for some other reason like that


For support for the first comment see the other article i mentioned further on in my post. Here the author makes the comment
One such surprise occurred on Vancouver Island, British Columbia, Canada, when a sponge of Upper Triassic ‘age’ (the standard geological time scale is used for communication purposes only) was discovered in a carbonate formation.1 It was named Nucha? vancouverensis sp. nov. Now, the formation where the sponge was found is considered a standard reference for the North American Triassic because of its ammonoid index fossils. Surprisingly, the sponge is nearly identical to one previously found only in the Middle Cambrian of western New South Wales, Australia, named Nucha naucum.2
In spite of the obvious similarity, because the Vancouver Island specimen was not exactly the same as its Australian counterpart, a question mark was placed after its genus name and it was given a different species name. Still, the researcher who reported the find, George Stanley, believes the similarities are striking enough to put the fossil in the same genus.
There was a better quote than that somewhere else but can't seem to find it anymore.

So, can you provide me with some objective criteria whereby you judge which types of change are possible and which types are not? I suspect that "types of change," in the end, will still end up being "amounts of change," anyway.
As i said in my post, for the purposes of this particular debate I think any type of known change can be used for your arguments irrespective of whether I believe they add information or not. At least that is my position at the moment.

If it can happen rapidly, why can't it happen slowly?
If speciation is the accumlation of very small changes then surely this would mean that genomes are always "moving" in some sort of direction and that these changes would be too small to be picked up by natural selection. If organisms are really this fluid then stasis presents an even bigger problem. I think that there is a need for organisms to maintain a balance of stability and the ability to adapt quickly to a new environment.

You should take all arguments with a grain of salt.
Amen
This message is a reply to:
 Message 23 by Blue Jay, posted 10-17-2009 2:11 AM Blue Jay has responded

Replies to this message:
 Message 26 by Blue Jay, posted 10-17-2009 6:06 PM Arphy has responded

    
Blue Jay
Member (Idle past 590 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 26 of 61 (531427)
10-17-2009 6:06 PM
Reply to: Message 25 by Arphy
10-17-2009 7:54 AM


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

Arphy writes:

I am arguing that a lack of significant change in the morphology of organisms over vast periods of time is not compatible with the general evolutionary framework.

And I have been trying to get you to be more specific. What counts as "significant change"? And, what counts as "vast periods of time"?

Here is a list of “types of change” in evolutionary biology:

Changes in the structure of important molecules
Changes in immune chemistry
Changes in hormone activation
Changes in developmental timing and sequencing
Changes in tissue specialization
Changes in the efficiency of organs
Changes in the function of organs
Changes in the size of body parts
Changes in the arrangement of body parts
Changes in the shape of body parts
Fusion of two body parts into one
Division of one body part into two
Changes in the number of body parts
Changes from asexual to sexual reproduction
Changes from ovipary (egg laying) to vivipary (live birth)

Which of these types of change, in your mind, count as significant change?

And, why do you think these things have to happen under the “general evolutionary framework”?

-----

Arphy writes:

If speciation is the accumulation of very small changes then surely this would mean that genomes are always "moving" in some sort of direction and that these changes would be too small to be picked up by natural selection.

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


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

Darwin loves you.


This message is a reply to:
 Message 25 by Arphy, posted 10-17-2009 7:54 AM Arphy has responded

Replies to this message:
 Message 27 by Arphy, posted 10-26-2009 3:51 AM Blue Jay has responded

  
Arphy
Member (Idle past 2325 days)
Posts: 185
From: New Zealand
Joined: 08-23-2009


Message 27 of 61 (532731)
10-26-2009 3:51 AM
Reply to: Message 26 by Blue Jay
10-17-2009 6:06 PM


Re: Phase 1: Defining "Stasis"
Hi Bluejay!

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. 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. Also surely there would have been many changes in environments and ecosystems throughout the earth over the millions of years of evolutionary time.
For this debate, by vast periods of time I mean anything from a few million years to a few billion years.

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

e.g. What about "neutral" mutations?
This message is a reply to:
 Message 26 by Blue Jay, posted 10-17-2009 6:06 PM Blue Jay has responded

Replies to this message:
 Message 40 by Blue Jay, posted 10-27-2009 9:23 AM Arphy has not yet responded
 Message 49 by RAZD, posted 10-27-2009 8:16 PM Arphy has not yet responded

    
Kaichos Man
Member (Idle past 2380 days)
Posts: 250
From: Tasmania, Australia
Joined: 10-03-2009


Message 28 of 61 (532850)
10-26-2009 10:22 PM
Reply to: Message 1 by Blue Jay
10-05-2009 11:17 AM


So, in summary, my position is that Arphy’s view (that stasis should not happen if things evolve) comes from an oversimplified understanding of evolution, and of the processes and functions of life.

G'day Bluejay.

Personally, I think it's a fine table!

If I have understood your post correctly, you are saying that stasis doesn't mean that evolution has stopped, that forces not reliant on phenotypic change are still at work on the population. Is that correct?

Undoubtedly this is true. I have long argued, for example, that one of the problems faced by evolution per se is that what might be termed the "Olympian" advantages (faster, stronger, higher, fiercer) are always going to count for more than the next-to-worthless budding of some speculative new anatomical feature.

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.

Unfortunately, this creates two more significant problems for evolution.

The first is that, logically, if stasis indicates success, then phenotypic modification must indicate failure. An organism will only evolve when it is under survival stress. This makes every substantial evolutionary step a race against extinction.

The second problem is that vast amounts of time spent in stasis greatly reduce the time available to evolve. For example, Haldane's Dilemma sets a limit on human/common ancestor evolution over 10 million years of 1667 mutations. 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!

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

Edited by Kaichos Man, : typos


"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 1 by Blue Jay, posted 10-05-2009 11:17 AM Blue Jay has responded

Replies to this message:
 Message 29 by Coyote, posted 10-26-2009 10:51 PM Kaichos Man has responded
 Message 30 by Otto Tellick, posted 10-27-2009 1:31 AM Kaichos Man has responded
 Message 31 by Arphy, posted 10-27-2009 4:48 AM Kaichos Man has not yet responded
 Message 44 by Blue Jay, posted 10-27-2009 9:47 AM Kaichos Man has not yet responded

    
Coyote
Member
Posts: 6117
Joined: 01-12-2008


Message 29 of 61 (532853)
10-26-2009 10:51 PM
Reply to: Message 28 by Kaichos Man
10-26-2009 10:22 PM


Unfortunately, this creates two more significant problems for evolution.

The first is that, logically, if stasis indicates success, then phenotypic modification must indicate failure. An organism will only evolve when it is under survival stress. This makes every substantial evolutionary step a race against extinction.

...

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

It depends on the environment.

If the environment stays about the same, then staying about the same is the correct way for a species to survive. Any radical changes would be contra-survival.

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?


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
This message is a reply to:
 Message 28 by Kaichos Man, posted 10-26-2009 10:22 PM Kaichos Man has responded

Replies to this message:
 Message 39 by Kaichos Man, posted 10-27-2009 9:09 AM Coyote has not yet responded

  
Otto Tellick
Member (Idle past 223 days)
Posts: 288
From: PA, USA
Joined: 02-17-2008


Message 30 of 61 (532869)
10-27-2009 1:31 AM
Reply to: Message 28 by Kaichos Man
10-26-2009 10:22 PM


Haldane's Dilemma? Gould and Eldridge? What??
I'm sorry, KM, but I think you'll need to be a little more specific in your erudite references. (And maybe you need to be more careful about actually understanding the sources you are referring to.)

Kaichos Man writes:

... vast amounts of time spent in stasis greatly reduce the time available to evolve. For example, Haldane's Dilemma sets a limit on human/common ancestor evolution over 10 million years of 1667 mutations.

I did a quick wikipedia check on Haldane's dilemma -- if you feel this is insufficient, do please direct me to a better source. The term stems from a 1957 publication (not very current, as these things go). The opening paragraph of the wikipedia entry mentions that "Today, Haldane's Dilemma is raised mostly by creationists opposed to evolution, who claim it is evidence against large-scale evolution..." The 2nd paragraph is succinct:

quote:
Haldane stated at the time of publication "I am quite aware that my conclusions will probably need drastic revision", and subsequent corrected calculations found that the cost disappears. He had made an invalid simplifying assumption which negated his assumption of constant population size, and had also incorrectly assumed that two mutations would take twice as long to reach fixation as one, while sexual recombination means that two can be selected simultaneously so that both reach fixation more quickly. The creationist claim is based on further errors and invalid assumptions.

The math in the wikipedia entry is admittedly "above my pay grade", but I didn't see any reference to 1667 mutations or 10 million years -- do you have a better reference for those numbers you mentioned (especially one that isn't 50 years old and subsequently refuted)?

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!

(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. But apart from that...

Either you have a peculiar inability to express your belief coherently, or else your belief is the result of a staggering misunderstanding. G&E speak of "stasis" as being the typical quality of genetic descent over long periods of time that stand between relatively brief periods of significant adaptation due to relatively intense changes in the pressures applied by natural selection (e.g. climate change). This has no relation whatsoever to any notion of "stasis" over the life span of organisms within the population of a given species.

Is it the case that you totally misunderstand the concept of punctuated equilibrium as applied to the ToE, or are you simply not able to describe the concept correctly? (I'm inclined to accept the pedagogical approach that says if the student is unable to explain the idea, s/he does not adequately understand it.)

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"), as a courtesy to the people who actually know more about these things, so they can point to the specific steps where you make your mistakes.


autotelic adj. (of an entity or event) having within itself the purpose of its existence or happening.
This message is a reply to:
 Message 28 by Kaichos Man, posted 10-26-2009 10:22 PM Kaichos Man has responded

Replies to this message:
 Message 32 by Dr Jack, posted 10-27-2009 5:45 AM Otto Tellick has acknowledged this reply
 Message 38 by Kaichos Man, posted 10-27-2009 8:53 AM Otto Tellick has acknowledged this reply

  
Prev1
2
345Next
Newer Topic | Older Topic
Jump to:


Copyright 2001-2015 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2018