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Author Topic:   MACROevolution vs MICROevolution - what is it?
Faith 
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Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 244 of 908 (816850)
08-12-2017 3:48 AM
Reply to: Message 240 by PaulK
08-12-2017 2:56 AM


Re: the usual silly wrong linear analogy
1) The Pod Mrcau lizards are a very unusual case. Taking such cases as typical is an obvious mistake
And what example would you put forward as typical?
2) We do not know the basis of the phenotypic changes in the lizards - it may be partly (or even wholly) an environmental response which would be much quicker.
Just normal sexual recombination over generations is the simplest explanation, bringing out the large heads and jaws simply due to their genes being high frequency in the original population, purely randomly.
If a dozen human beings get isolated on an island for a few hundred years some striking traits are likely to come to characterize the whole population after that time just because of the recombination of the genes possessed by the original dozen.
An environmental response should in reality be much slower if the large headed adaptation was rare in the original group, and in fact not even expressed phenotypically, since the unadapted lizards would be living with a major handicap until it became high frequency. In fact this scenario could involve great loss to the population until the adapted form spreads, and that would mean even greater loss of genetic diversity than the scenario I'm assuming as all the possessors of low frequency genes would rapidly disappear and not be part of the reproducing few. In my scenario all are capable of reproduction, the same food supply is available on the island as the mainland where the parent population continues to live, a large head and jaws shows up purely by sexual recombination over a few generations and eventually spreads through the whole population, determining the choice of food rather than the other way around.
3) We do not know if the lizards would interbreed with the ancestral species - and we do know that Jutland cattle CAN interbreed with other cattle. So we cannot say that either represents full speciation.
I'm not interested in "full speciation," merely the fact that recognizable phenotypic changes fairly rapidly result from simple random selection of a small number of individuals out of a larger population, showing that simple sexual recombination of a new set of gene frequencies is all it takes to get a new variety. If "full speciation" has not yet arrived, it will eventually if reproductive isolation continues.
It also should show that developing new phenotypes requires genetic loss because the traits in one subpopulation are different from those in the others.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 240 by PaulK, posted 08-12-2017 2:56 AM PaulK has replied

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 Message 245 by PaulK, posted 08-12-2017 4:01 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 246 of 908 (816852)
08-12-2017 4:53 AM
Reply to: Message 245 by PaulK
08-12-2017 4:01 AM


Re: the usual silly wrong linear analogy
I would be looking at examples considered incipient species, or maybe introduced animals on other islands.
Well until you can come up with one you don't have much of an argument.
Remember that the lizards got a lot of attention because the change was so dramatic.
It was only so dramatic because it contradicted evo expectations, not because there is any evidence in reality that supports those expectations.
Do you have any other examples of such dramatic change over so short a time ?
The Jutland cattle seem to fit. Even the record of breeds that only take a hundred years or so to develop from wild stock to pure bred, as in many cattle breeds. Any founder effect will fit of course and I do regard those as species.
The circumstances are unusual which is why the ToE fantasy can go on unchallenged. But these few examples ought to be a challenge, even the lizards alone, especially in the absolute absence of any contrary evidence.

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 Message 245 by PaulK, posted 08-12-2017 4:01 AM PaulK has replied

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 247 of 908 (816853)
08-12-2017 4:58 AM
Reply to: Message 245 by PaulK
08-12-2017 4:01 AM


Re: the usual silly wrong linear analogy
Although full speciation IS important because otherwise your new variety could just be absorbed back into the main population if the geographic barriers ceased to be a factor.
Not important at all since just getting a clearly identifiable new variety demonstrates that the changes do not require anywhere near the time the ToE assumes.
And surely it is obvious that because the population started from such few numbers there should be a great deal of homozygosity in the genome, meaning severely reduced genetic diversity. If this is doubted then DNA should be tested.

This message is a reply to:
 Message 245 by PaulK, posted 08-12-2017 4:01 AM PaulK has replied

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 Message 249 by PaulK, posted 08-12-2017 5:10 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 250 of 908 (816856)
08-12-2017 5:58 AM
Reply to: Message 249 by PaulK
08-12-2017 5:10 AM


Re: the usual silly wrong linear analogy
It should be obvious, for instance, that none of the lizards brought to the island displayed the new phenotype.
Yes that is obvious, but so is it obvious that none of Darwin's pigeons started out with their exaggerated characteristics. They came about through a series of selected matings, showing that the potential was originally in the genome though unexpressed. This is in fact an argument for the effect of sexual recombination over generations of the genetic material in the original small number of individuals, as opposed to mutations or environmental pressure etc.

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 Message 249 by PaulK, posted 08-12-2017 5:10 AM PaulK has replied

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 252 of 908 (816865)
08-12-2017 10:53 AM
Reply to: Message 251 by PaulK
08-12-2017 7:02 AM


Re: the usual silly wrong linear analogy
= Yes that is obvious, but so is it obvious that none of Darwin's pigeons started out with their exaggerated characteristics.
Which means that selection is required in addition, and quite strong selection IF the differences are due to genetics.
We already have pretty strong selection in the fact that only ten individuals made up the founding population so that there was a very small gene pool undergoing recombination over the generations. No further selection is needed since the genetic stuff for the larger heads was in that gene pool to begin with, and probably in more than one individual, so that recombination itself would have been enough to bring that characteristic to expression -- and increase it from generation to generation too, as Darwin increased the odd traits of his pigeons. In other words limited mating opportunities from a genetic standpoint could be sufficient selection to bring out the trait. There could have been some additional form of selection as well, but my point is it wouldn't have been needed given the founding numbers.
That is one of the reasons for suspecting environmental response as at least a partial cause of the differences - that would skip the need for selection and work much quicker.
I'm not following your reasoning. First, the small number of founding individuals is already strong selection of a very small gene pool, and second, what can you mean by "environmental response" if not selective pressure from the environment? Either way you've got selection in operation.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 251 by PaulK, posted 08-12-2017 7:02 AM PaulK has replied

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 Message 253 by PaulK, posted 08-12-2017 11:11 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 254 of 908 (816867)
08-12-2017 11:30 AM
Reply to: Message 253 by PaulK
08-12-2017 11:11 AM


Re: the usual silly wrong linear analogy
Sorry, the word "selection" doesn't have to mean it has a purpose, it is certainly random selection when a particular small number of individuals is reproductively isolated, because only the genetic material from that small group becomes the foundation of the characteristics of the population that eventually emerges.
If you make a pile of small objects and take a random handful out of the pile to put to use, you've selected that handful in the sense I'm using the term. Or randomly drawing a few tickets out of the pool for a lottery is the same kind of selection.
It is descriptive of the common event of forming a daughter population from a limited number of individuals, often brought about by migration away from the parent population, but also formed within a population by drift and so on.
You might withhold your insults until you understand the situation.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 253 by PaulK, posted 08-12-2017 11:11 AM PaulK has replied

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 256 of 908 (816882)
08-12-2017 6:48 PM
Reply to: Message 255 by PaulK
08-12-2017 11:47 AM


Re: the usual silly wrong linear analogy
I didn't assume a purpose. But there must be some causal reason why those individuals were selected relating to the features in question. And there is not.
No there doesn't have to be any causal reason, it was purely random, they simply happened to have genes for big heads and jaws that didn't get phenotypically expressed until there were enough of them in few enough individuals to bring it about over some number of generations. They didn't have to have them, there is no reason to think they couldn't have survived well enough without them, but their genes brought out that trait and it caused them to change their diet.
it is certainly random selection when a particular small number of individuals is reproductively isolated,
That is drift, not selection.
Drift is a form of random selection that occurs within a population. There are other forms such as the random selection of some number of individuals that migrate away from the parent population. It's selection in the sense I described and it's random.

This message is a reply to:
 Message 255 by PaulK, posted 08-12-2017 11:47 AM PaulK has replied

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 Message 257 by PaulK, posted 08-13-2017 1:42 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 258 of 908 (816893)
08-13-2017 3:52 AM
Reply to: Message 257 by PaulK
08-13-2017 1:42 AM


Re: the usual silly wrong linear analogy
Drift occurs within a population as I understand it, and I've never seen the random formation of a separated daughter population called drift.
The selection needed to explain the rapid change is in the original small number of founders, that original random selection. Such a small number is all that is needed for very rapid change. And thirty years is far more than would be needed; the change should come about within a few generations, give it ten years.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

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 Message 257 by PaulK, posted 08-13-2017 1:42 AM PaulK has replied

Replies to this message:
 Message 259 by PaulK, posted 08-13-2017 3:59 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 260 of 908 (816895)
08-13-2017 4:06 AM
Reply to: Message 259 by PaulK
08-13-2017 3:59 AM


Re: the usual silly wrong linear analogy
The same way Darwin's pigeons did not have the traits they came to have after his assiduous selection program.
"Without a change in allele frequencies?" You are really not getting this. The founding population has the different allele frequencies from their parent population. It is those new allele frequencies that bring out the larger head and jaws over a number of generations of sexual recombination among those new allele frequencies. It is you who aren't thinking.

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 Message 259 by PaulK, posted 08-13-2017 3:59 AM PaulK has replied

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 Message 261 by PaulK, posted 08-13-2017 4:22 AM Faith has replied
 Message 275 by Taq, posted 08-14-2017 10:51 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 262 of 908 (816897)
08-13-2017 6:04 AM
Reply to: Message 261 by PaulK
08-13-2017 4:22 AM


Re: the usual silly wrong linear analogy
Yes I do think the same kind of result can come about through either Darwin's selection or the random combination of genetic material in a randomly assembled founding population, though it would no doubt take longer in the random scenario to get all the relevant genetic material into the mix. It all depends on what genes were present in that founding population and nobody knows but it can be inferred from the results that whatever increases head and jaw size was present and dominant and would be increased over generations of recombination. While there may have been additional factors involved, I don't see any need for them.
If you don't see that the small founding number is already a new set of gene frequencies that will determine the development of the lizard population, you really have NOT thought about it enough despite your declarations.
Are we really to believe that the vast majority of gene combinations taken from the original founders have the new traits ?
I would expect it to emerge over a number of generations, not be a matter of "vast majority" but something that gets increased over time. That's how I think of Darwin's pigeons. He'd pick a pigeon with a very slightly larger breast perhaps and breed for that characteristic, finding that all it takes to increase it is repeating matings of the birds that have that characteristic. I don't see why this couldn't happen randomly. We're not talking about "new traits," all it takes is ordinary sexual recombination of a new set of gene frequencies to bring out hitherto unexpressed traits over a number of generations.
That it was just by chance that none of the founders had those traits ? It's absurd. And it is the only way you could be right.
There's a lot of stuff potential in the genome of any animal that doesn't get expressed except under special circumstances, including random selection of a small founding population, especially effects that increase over generations like the exaggerated pigeon breasts or the exaggerated lizard heads. You get quite noticeable differences from population to population in a ring species and there's no reason to assume anything other than inbreeding of changed gene frequencies to explain it.
However, it is possible that the founding population did contain a lizard or two or three that had a slightly larger head than the others, but not enough to be noticed. Surely Darwin's original slightly larger pigeon breast was hardly noticeable. If the trait in question is governed by more than one gene, which is the case with most traits after all, then increasing it over generations isn't a big mystery.
Consider the example of a recessive allele. Even if you picked a founder population who all had one copy of that allele you would still only have a frequency of 50%. For the trait associated with that allele to take over the population that allele would have to increase in frequency to 100%.
Well, in my scenario all genes originally had only two alleles, and that's my default assumption, so each individual of the founder population should have had at least one copy of the recessive allele. Following normal Mendelian genetics that allele should frequently be homozygous in subsequent generations. But there are probably many genes that affect head and jaw size so with such small founding numbers we should be getting homozygosity at many of those loci in a few generations, increasing the effect. We could suppose something like sexual selection at this point to speed up the processes involved.
Believe it or not I'm just pursuing what looks to me like the evidence, none of this has anything to do with "what I want" so you can stop with the incessant insults. Darwin's pigeons came to mind at one point, I wasn't looking for that angle on things. It's interesting because it suggests the possibility of increasing size over generations just from ordinary sexual recombination. However, I don't need it to argue for ordinary sexual recombination of new gene frequencies since that's my standard argument for even the most dramatic changes over short periods of time.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

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 Message 261 by PaulK, posted 08-13-2017 4:22 AM PaulK has replied

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 Message 263 by PaulK, posted 08-13-2017 6:40 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 264 of 908 (816899)
08-13-2017 7:32 AM
Reply to: Message 263 by PaulK
08-13-2017 6:40 AM


Re: the usual silly wrong linear analogy
You don't need additional selection if the original founding gene frequencies have clear highs and lows, which is likely to be the case among such a small number of individuals. Extreme lows will become lower and drop out over time, while the highs come to dominate.
I don't need your abusive attitude.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 263 by PaulK, posted 08-13-2017 6:40 AM PaulK has replied

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 Message 265 by PaulK, posted 08-13-2017 8:08 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 266 of 908 (816913)
08-13-2017 1:01 PM
Reply to: Message 265 by PaulK
08-13-2017 8:08 AM


Re: the usual silly wrong linear analogy
Your attitude is abusive and all I've been doing is pursuing my thoughts about these things so you have no excuse.

This message is a reply to:
 Message 265 by PaulK, posted 08-13-2017 8:08 AM PaulK has replied

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 267 of 908 (816914)
08-13-2017 1:04 PM
Reply to: Message 265 by PaulK
08-13-2017 8:08 AM


Re: the usual silly wrong linear analogy
I'll say it again. If Darwin could get traits from a founding pair of pigeons that didn't exist in either one of them, the lizards could also produce such a new trait just from previously unexpressed combinations of existing genes.
Fine, add drift, but drift is a form of selection and it can happen just as rapidly as what I'm talking about from one generation to the next.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 270 of 908 (816956)
08-14-2017 10:24 AM


Evolution has a built-in stopping point
Before it gets completely lost, I would just like to restate my original position, which is sometimes affirmed by PaulK and others, but nevertheless gets easily lost in side issues:
Evolution is not a straight linear one-foot-after-the-other process because in order to get new varieties or races or breeds or species the genetic material for other varieties must be reduced, and completely lost in some cases.
I think a daughter population can show dramatic changes from the parent population in a relatively short period of time simply from the random selection of a small founding population. I gave the example of the release of five pairs of lizards onto the Pod Mrcaru island, which developed big heads and jaws over thirty-plus years. I don't think more than the random selection of a small number of individuals is needed to explain this, as there would most likely be dramatic new gene frequencies in the founding number which would bring out the changes simply through a few generations of sexual recombination.
I brought this up because the necessary genetic loss is never acknowledged in discussions of evolution, and the computer simulation models perpetuate the same wrong idea of an unimpeded series of changes from microevolution to macroevolution. Apparently even when they take "selection" into account they fail to represent this fact.
Edited by Faith, : No reason given.

Replies to this message:
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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 272 of 908 (816963)
08-14-2017 10:46 AM
Reply to: Message 271 by Taq
08-14-2017 10:42 AM


Re: the usual silly wrong linear analogy
Adding genetic diversity through mutations does not halt evolution.
There has to be selection from the genetic diversity in order to get a new variety or breed or race or species, and if it isn't selected it's just scattered new phenotypes in a large population, which is not evolution, which means change in the population. If you call everything evolution you are just playing a semantic game and confusing things.

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 Message 271 by Taq, posted 08-14-2017 10:42 AM Taq has replied

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