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Author Topic:   Introduction to Genetics
RAZD
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From: the other end of the sidewalk
Joined: 03-14-2004
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(1)
Message 136 of 236 (719599)
02-15-2014 6:12 PM
Reply to: Message 134 by Faith
02-15-2014 5:26 PM


The problem with that system, RAZD, is that while it's technically true enough it blurs the line where you get another Kind from a former Kind, which is still what the ToE claims ...

Once again, evolution does not say that. It is always nested hierarchies, and no evolution at any stage steps outside the hierarchy they come from -- that would in fact counter evolution and falsify evolution.

... . All you are doing is insisting that the change comes about so gradually that one can't identify that line at all, basically trying to define the debate out of existence. ...

Not really sure what you are saying here, but as far as I can see there are two basic differences between evolution and creation:

  1. age of the earth
    • creation happened circa 6,000 (to 12,000 depending on sources) years ago vs
    • scientific data\evidence shows a measured minimum age of 4.5 billion years and

  2. the number of original parent populations
    • creation has a number of fairly advanced created kinds (number unknown, but they filled the ark)
    • scientific data\evidence shows a small number of primitive single cell organisms are most likely the rood source of all life on earth

They are somewhat interlinked -- greater age benefits evolutionist views (makes it more feasible), shorter age benefits creationist views (makes it more feasible).

Another way to look at is the three kinds/clades in Message 133 have a common ancestor by evolutionary views and that they don't have a common ancestor by creationist views.

This leads to a testable prediction: evolution if every group can be linked to any other group via common ancestors as you go back in time with and end in some single cell breeding population; creation if common ancestors cannot be found between groups at a specific fairly recent point in time.

ie -- evolution if the yellow, orange and red clades are found to have a parent common ancestor population that they are each descendant from; creation if there is no parent common ancestor population found.

In one sense this should also be able to tell us how many "kinds" there are by looking at the nested hierarchies (that are predicted by both views) and seeing where the end up in a parent common ancestor that is not descendant from another earlier parent population.

In addition we can test for the flood by looking for a common genetic bottleneck at the time of the ark.


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 134 by Faith, posted 02-15-2014 5:26 PM Faith has responded

Replies to this message:
 Message 137 by Faith, posted 02-15-2014 6:21 PM RAZD has acknowledged this reply

  
Faith
Member
Posts: 32148
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 137 of 236 (719600)
02-15-2014 6:21 PM
Reply to: Message 136 by RAZD
02-15-2014 6:12 PM


This leads to a testable prediction: evolution if every group can be linked to any other group via common ancestors as you go back in time with and end in some single cell breeding population; creation if common ancestors cannot be found between groups at a specific fairly recent point in time.

But again all you are going to do is define this common ancestor into existence from your charts, not from knowing that there was in fact genetically such a common ancestor.

In one sense this should also be able to tell us how many "kinds" there are by looking at the nested hierarchies (that are predicted by both views) and seeing where the end up in a parent common ancestor that is not descendant from another earlier parent population.

Again, a lot of manipulation on paper, and no proof in actual reality.

In addition we can test for the flood by looking for a common genetic bottleneck at the time of the ark.

Greater heterozygosity in the long-lived people and creatures on the ark, but you probably aren't going to find any of those anywhere and if you did, not in a condition where you could test their genome. After the ark my creationist theory would predict a rapid increase in homozygosity in the genome of all the creatures. Today's percentage ABE: OF HETEROZYGOSITY /ABE in human beings is about 7%; a guess would be 30 to 50 percent or more in the generation right before the Flood and the eight on the ark who had lived before the Flood. After that there should be a rapid decrease in heterozygosity. Got a way to test for this?

ABE: Oh and a lot less "junk DNA," a LOT less.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 136 by RAZD, posted 02-15-2014 6:12 PM RAZD has acknowledged this reply

    
RAZD
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Posts: 19978
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 138 of 236 (719604)
02-15-2014 6:41 PM
Reply to: Message 135 by Faith
02-15-2014 5:36 PM


... variability (not "viability"), ...

Ooops I'll fix thanks.

But the problem is you aren't looking for reduction in genetic variability (not "viability"), which is why you have not "seen" it. You are not looking where it would be found. There is no way this is NOT the case. ...

As whole genomes become sequenced and the variations of individuals mapped against a "species standard" genome, there is no way that this variability will NOT be mapped.

As it stands with the current state of genomes there are no locations holding hidden variations sufficient to result in anything more than variation level change that would be expected via evolution views of mutations moving a section of DNA from one location to another -- not enough to change a domestic cat into a tiger or vice-versa ... which of course would be within what is expected of the evolutionary model.

Should we expect anything more from the creationist model?

... When you have a population based on reduced numbers you HAVE to get reduced genetic variability in the population as a whole, ABE: though this may not be apparent until the numbers have been appreciably reduced so that the trend can become apparent. At first you'll just get the usual remix, the new gene frequencies, and new phenotypes from them, but in order to do that you have to reduce the competing alleles, and this only becomes apparent as an overall reduction in alleles as you get further population splits. This COULD be demonstrated in a laboratory. /ABE

Basically what you are saying is that each speciation results in a genetic bottleneck for the subspecies. And that this would be a permanent condition for the subspecies.

And thus we can test for whether

  1. subpopulations after a speciation event have less variation than the parent population, and
  2. the genetic variability stays at a low level after a speciation event.

Would you agree that if the initial cause of reproductive isolation was physical isolation -- say the parent population occupies a peninsula and an earthquake or hurricane causes part of the peninsula to become an island, with a gap that this population cannot cross -- that the population on the remaining peninsula and on the island have the same amount of variation\variability?


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 135 by Faith, posted 02-15-2014 5:36 PM Faith has responded

Replies to this message:
 Message 139 by Faith, posted 02-15-2014 7:46 PM RAZD has responded

  
Faith
Member
Posts: 32148
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 139 of 236 (719608)
02-15-2014 7:46 PM
Reply to: Message 138 by RAZD
02-15-2014 6:41 PM


Predictability of Genetic Variability
As whole genomes become sequenced and the variations of individuals mapped against a "species standard" genome, there is no way that this variability will NOT be mapped.

As it stands with the current state of genomes there are no locations holding hidden variations sufficient to result in anything more than variation level change that would be expected via evolution views of mutations moving a section of DNA from one location to another -- not enough to change a domestic cat into a tiger or vice-versa ... which of course would be within what is expected of the evolutionary model.

Should we expect anything more from the creationist model?

The best way to see a trend in the amount of genetic variability would be by comparing genomes from a series of population splits into daughter populations where you know the number of founding individuals and what sort of phenotypic changes came to characterize each population over some known number of generations. I've come to think of the percentage of heterozygosity as the main indicator, and I've thought this could be tested by looking for the percentage of heterozygosity in a series of ring species in the wild, but probably the best test would be in the laboratory where you could control for all the variables.

Basically what you are saying is that each speciation results in a genetic bottleneck for the subspecies. And that this would be a permanent condition for the subspecies.

Not a bottleneck because that involves a very drastic reduction in numbers for the founding of a new population, and I'm thinking of a more normal-sized founding population. But I AM saying that the trend to [ABE: REDUCED/ABE] genetic variability should be the case in all such population splits anyway, and yes, that it would be a permanent condition for the subspecies barring a reintroduction of gene flow.

And thus we can test for whether

a. subpopulations after a speciation event have less variation than the parent population, l...

No RAZD, not "less VARIATION," but less GENETIC VARIABILITY. There is a big difference. You may be getting much greater variation in the phenotypes, in fact you should, but the genetic variability should also be getting reduced in the process.

b. the genetic variability stays at a low level after a speciation event.

OK. You are of course counting on mutations, which of course you expect to be viable mutations that make real alleles and occur in the germ cells so they can be passed on. But if such mutations did enter into the picture it should have the same effect as the reintroduction of gene flow from any source: that is, it would change the new subspecies' phenotypic character into something else. It would in effect be a new "speciation" or subspeciation. But I don't think you'd find any genuine increase in the genetic variability anyway, so OK, yes, that would be a test.

Would you agree that if the initial cause of reproductive isolation was physical isolation -- say the parent population occupies a peninsula and an earthquake or hurricane causes part of the peninsula to become an island, with a gap that this population cannot cross -- that the population on the remaining peninsula and on the island have the same amount of variation\variability?

I'm not sure why HOW the formation of a daughter population should change things. Migration of the new population to a new geographic area would accomplish the same thing, assuming reproductive isolation as well. In any case it depends on the numbers involved. If the number of individuals on the new island is appreciably smaller than the number in the parent population [ABE: actually the population left on the peninsula which may or may not reflect the genetic situation of the original parent population /ABE] it should show a reduction in genetic variabilithy, but not right away. At first if you checked individual genomes they'd have the same genetic variability of course. It would take a few generations for the different gene frequencies in the two populations to show up in the development first of many different phenotypes and then a recognizable new phenotypic character for the population as a whole, and that's when I'd expect a reduction in genetic variability to start to become measurable.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 138 by RAZD, posted 02-15-2014 6:41 PM RAZD has responded

Replies to this message:
 Message 143 by RAZD, posted 02-17-2014 11:36 AM Faith has not yet responded

    
herebedragons
Member
Posts: 1513
From: Michigan
Joined: 11-22-2009
Member Rating: 10.0


Message 140 of 236 (719695)
02-16-2014 4:58 PM
Reply to: Message 131 by Faith
02-15-2014 5:10 PM


Re: Factual versus interpretive tendentious terminology
I will combine some points from Message 130 in this reply to keep my response on one topic.

As I think I've said somewhere up thread, macroevolution is the only one I really don't want to use.

Fine with me. I won't use it. You may have to accept that others may use the term and you just need to be clear about what they are actually referring to.

I tried to be very clear that I am NOT refusing to use the term "speciation" but that in fact I DO use it BECAUSE I know it would cause confusion not to.

I didn't think you were refusing to use it but were protesting the implications of it. Like this next statement:

"Speciation" implies something other than the usual development of a subspecies, it implies something outside the Kind or Species itself, a step outside

I don't think you mean to suggest that all members of the dog "kind" are all just subspecies, do you? This would require revising taxonomic classifications, which is not really feasible. No, if you were to accept that all extant members of the family Canidae diversified from a single pair of ancestors, then you will just have to accept that that diversity crossed genus and species lines.

But after all this rather rancorous discussion, I think I'm ready to just leave it all alone and struggle through the establishment terms as well as I can.

I understand better what your objections are and will try to do my best to accommodate them.

What you are actually disagreeing with is the mechanisms that lead to that event, not the event itself

I certainly don't see how this is true. Population splits are the best example of how new subspecies are formed, and I make a lot of my case about how this leads to decreased genetic variability from this example, so the idea I'm objecting to the mechanisms makes no sense.

Your proposed mechanism for speciation is geographic isolation with a reduction in genetic diversity. It is this reduction in genetic diversity that causes the two populations to be identified and separate species or subspecies. This is not what mainstream thinking proposes.

I AM objecting to the idea that what they lead to is a new "species" rather than just another subspecies. I see no justification for that term since the mechanisms are not different.

We will have to discuss speciation more in depth later on, you do have a different idea of how speciation works (ie. the mechanism).

I might add here that although it hasn't come up in this discussion so far, I've been half expecting someone to question that description and maybe you should since it may not ALWAYS lead to inability to interbreed? Please clarify. If it doesn't, then I don't know what there is to differentiate this new population from any other subspecies.

How to define species is not always straight forward. According to the Biological Species Concept, species are groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups. Although this is a pretty useful definition and probably the most common, there are many cases that just can't be defined in this way.

As I stated in another message Message 366 ... the best way to think about species is that they are distinctive populations of organisms that a separate classification enables more effective communication about that population. Inter-fertility is usually considered a criteria of separating species, but it is not always set in stone.

In other words, when two populations become significantly different from each other and gene flow between those populations is greatly restricted or nonexistent, they probably should be referred to as separate species. Subspecies usually refers to populations that occupy different geographic regions but produce hybrids in nature where their ranges overlap. The two populations usually have distinctive differences so that individuals can be identified as members of their respective populations.

Yes the fox example looks like a lot of change in the structure of the genome, so either that isn't a determinant of a Kind or there is something else in the genomic structure that determines it.

I am not going to advocate that the family Canidae represents the dog kind. I can only go by what the creationist experts say about that. Just know up front that number of chromosomes is not an indication of genetic diversity, but instead, it appears that the genomes have undergone heavy rearrangement. That is something we will have to explore at a later time.

As for going on to discuss genes, chromosomes and alleles, ...The question that I began with was about identifying one species from another genetically.

That is a difficult question to start with. I think I will start a thread on basic genetics and if you want to follow, fine.

HBD


Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca

"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.

Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.


This message is a reply to:
 Message 131 by Faith, posted 02-15-2014 5:10 PM Faith has responded

Replies to this message:
 Message 141 by Faith, posted 02-16-2014 6:04 PM herebedragons has responded

  
Faith
Member
Posts: 32148
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 141 of 236 (719700)
02-16-2014 6:04 PM
Reply to: Message 140 by herebedragons
02-16-2014 4:58 PM


Re: Factual versus interpretive tendentious terminology
I don't think you mean to suggest that all members of the dog "kind" are all just subspecies, do you?

Yes, of course. There's the Kind and then there are subspecies or variations on the Kind.

I understand better what your objections are and will try to do my best to accommodate them.

Thank you.

What you are actually disagreeing with is the mechanisms that lead to that event, not the event itself

I certainly don't see how this is true. Population splits are the best example of how new subspecies are formed, and I make a lot of my case about how this leads to decreased genetic variability from this example, so the idea I'm objecting to the mechanisms makes no sense.

Your proposed mechanism for speciation is geographic isolation with a reduction in genetic diversity. It is this reduction in genetic diversity that causes the two populations to be identified and separate species or subspecies. This is not what mainstream thinking proposes.

No, it's my own theory which I think pretty clearly parallels a lot of creationist thinking, though the usual way it's thought about is that there is not an increase in "information." At some point I realized that phenotypic change by population splits actually requires a decrease in genetic variability in the new population as compared with the former population, and I know this isn't going to be apparent right away. The difference in gene/allele frequencies ought to be apparent pretty soon though. The new gene frequencies, more of some alleles, fewer of others, should produce new phenotypes in individuals in the new population within a few generations. This doesn't look like a decrease in genetic variability because you are also getting a higher percentage of some alleles along with a lower percentage of others. And in fact in the first daughter population all the alleles of the former MAY be present so you DON'T have a decrease. But you are NEVER going to have an increase unless there is resumed gene flow, and that of course destroys the whole example of population splits.

But if just one allele didn't make it into the new population that's a decrease, and that's very likely to happen with population splits. Again, it's never going to work the other way, you'll never have an increase because you are simply taking a portion of the existing alleles into the new population. So, never an increase, possibly no decrease, but nevertheless very likely a decrease, a loss of alleles. That's the trend.

And if the daughter population splits again then you are VERY likely to have a decrease in genetic variability, and this is what I think happens in ring species. And no this is not mainstream thinking at all. I think by the time a species has evolved around a ring the last population should have much less genetic variability than the first, and this should demonstrate the principle I keep arguing here: that such a decrease in genetic variability is inevitable in the processes of evolution that produce new phenotypes or varieties or races or breeds. And since that is the case, you have the processes of evolution working against the assumptions of the ToE, which needs more rather than less variability to be true.

The only answer to this is mutations, because they appear to provide an increase in genetic variability. IF they made viable alleles this would be true, but that's the same as reintroducing gene flow which would change the character of the population, so the species in a ring species, say, wouldn't remain that particular species. I just don't think that happens or could happen. But this IS the only objection there is to the scenario I keep laying out so eventually it will have to be better answered than I've done so far.

I AM objecting to the idea that what they lead to is a new "species" rather than just another subspecies. I see no justification for that term since the mechanisms are not different.

We will have to discuss speciation more in depth later on, you do have a different idea of how speciation works (ie. the mechanism).

In a sense there's no reason not to use "species" because it merely implies a new variety or race, but within the ToE it implies validation of the ToE itself so I think it helps to try to make a distinction.

I still don't see that I have a different idea of how speciation works, however, I'm simply insisting on calling it a subspecies so as to avoid the implication that the Kind can evolve or vary in any way outside the Kind.


This message is a reply to:
 Message 140 by herebedragons, posted 02-16-2014 4:58 PM herebedragons has responded

Replies to this message:
 Message 142 by herebedragons, posted 02-17-2014 9:53 AM Faith has responded
 Message 145 by NosyNed, posted 02-17-2014 12:10 PM Faith has not yet responded

    
herebedragons
Member
Posts: 1513
From: Michigan
Joined: 11-22-2009
Member Rating: 10.0


(1)
Message 142 of 236 (719738)
02-17-2014 9:53 AM
Reply to: Message 141 by Faith
02-16-2014 6:04 PM


Re: Factual versus interpretive tendentious terminology
Yes, of course. There's the Kind and then there are subspecies or variations on the Kind.

I realize this is your premise, but it is going to cause a lot of confusion to rewrite taxonomic classifications. It doesn't make sense to call the red fox, domestic dog, and crab-eating fox subspecies of the original created kind (we can call it Canidae originalis ). [ABE]or to have subspecies of subspecies[/ABE] Classifications are for human convenience to facilitate discussion. Grouping organisms into classifications help us better understand what we are talking about.

If you agree that there was an original "ark kind" which then split into two daughter populations, which split again into four daughter populations, etc ... , you will be able to develop a branching cladogram that will look something like this:

You may disagree with the arrangement, but you agree with the basic premise; that the members of the dog kind originated from a common ancestral group, Canidae originalis. Maybe you could propose a very general idea of how you think a tree would look like in you scenario. For example, I would think that the domestic dog would need to branch off very, very early since they have been part of recorded history for many, many years and have undergone heavy breeding. (also keep in mind that the tree shown doesn't include extinct species that are included in Canidae). Then we can apply some tests to your hypothesis to see how well the data supports it.

But if just one allele didn't make it into the new population that's a decrease, and that's very likely to happen with population splits.

A loss of a single allele is not likely to bring about a new subspecies. The situation would be much more complicated than that and require much more significant differences.

I wonder, do you think that two identical populations, if kept geographically isolated could eventually be recognized as separate subspecies? What would be the factors that would bring about that change?

avoid the implication that the Kind can evolve or vary in any way outside the Kind.

We can focus on diversification within the kind.

In order for your hypothesis to gain acceptance you not only need to show evidence that supports it, but you also need to describe what evidence would falsify it. You also need to describe what predictions could be made using this hypothesis. For example, you should be able to arrange all extant canids in a hierarchical pattern based on number of alleles, heterogeneity, number of genes, or some combination of genetic traits. In short, develop a model that explains the data better than the current one.

HBD

By the way, on one level I agree with you that population splits can and do reduce genetic diversity, what I disagree with is that it is the whole story.

Edited by herebedragons, : No reason given.


Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca

"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.

Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.


This message is a reply to:
 Message 141 by Faith, posted 02-16-2014 6:04 PM Faith has responded

Replies to this message:
 Message 171 by Faith, posted 02-19-2014 6:33 AM herebedragons has responded

  
RAZD
Member
Posts: 19978
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


(1)
Message 143 of 236 (719745)
02-17-2014 11:36 AM
Reply to: Message 139 by Faith
02-15-2014 7:46 PM


Re: Predictability of Genetic Variability
The best way to see a trend in the amount of genetic variability would be by comparing genomes from a series of population splits into daughter populations where you know the number of founding individuals and what sort of phenotypic changes came to characterize each population over some known number of generations. I've come to think of the percentage of heterozygosity as the main indicator, and I've thought this could be tested by looking for the percentage of heterozygosity in a series of ring species in the wild, but probably the best test would be in the laboratory where you could control for all the variables.

AND by doing a follow-up study to see if "genetic variability" stays at that level.

Not a bottleneck because that involves a very drastic reduction in numbers for the founding of a new population, and I'm thinking of a more normal-sized founding population. ...

But you only have two members to make up a whole breeding population from the kind\clade on the ark -- you don't\can't have "a more normal-sized founding population. "

... But I AM saying that the trend to [ABE: REDUCED/ABE] genetic variability should be the case in all such population splits anyway, and yes, that it would be a permanent condition for the subspecies barring a reintroduction of gene flow.

So any finding of increased "genetic variability" would invalidate and falsify your hypothesis?

Such as the E.coli increased variability that allowed one group to become citrate consumers while other groups and that group before the new ability was expressed.

No RAZD, not "less VARIATION," but less GENETIC VARIABILITY. There is a big difference. You may be getting much greater variation in the phenotypes, in fact you should, but the genetic variability should also be getting reduced in the process.

Now you are arguing a rather pointless opinion that is rather obviously invalid ... because variability would be the ability to vary -- which is what happens every time offspring are produced, all the indels and point changes that you just can't stop from happening.

... not "less VARIATION," but less GENETIC VARIABILITY. There is a big difference. ...

Indeed: one occurs (less variation) and one doesn't (less variability).

OK. You are of course counting on mutations, ...

Obviously, since they are a fact, they have been observed.

... which of course you expect to be viable mutations ...

Not quite: which of course we expect to be random. Whether or not they are viable is determined by the survival of the offspring to reach the point of further reproduction. Some will, and some won't. Note that somewhere around 75% of human blastocysts (zygotes that have implanted on the uterus wall) are later ejected as non-viable and that the remaining 25% still have mutations. This is observed data, not made up.

... that make real alleles ...

A possibility, but not highly likely from one mutation alone. For instance the E.coli mentioned above required two mutations, where the first one enabled the second to be functional, and subsequent generations from before that first mutation do not evolve the second, but that ones after it are so able. I would expect alleles for multicellular life to be more complicated.

... and occur in the germ cells so they can be passed on. ...

Which is necessary for heredity to occur - and thus of interest to evolution - but not all mutations affect germ cells and thus only affect the organism itself. Those in this later group could affect the development of the organism and it's ability to survive and even to reproduce, but they could not be inherited, and would be lost in the next generation.

Even ones that are in the germ cell can be lost in the next generation if there is failure to reproduce.

... But if such mutations did enter into the picture it should have the same effect as the reintroduction of gene flow from any source: ...

The likelihood of a mutation replacing a lost allele would be extremely low, while the likelihood of a mutation causing or assisting in causing a new allele would be much much higher.

... that is, it would change the new subspecies' phenotypic character into something else. It would in effect be a new "speciation" or subspeciation. ...

Not really, it would cause a new variation, but it would still be carried by a member of the breeding population, and only by selection for survival and reproduction can it be passed on to later generations. It would need to become "popular" within the breeding population before you could have a speciation\subspeciation demarcation of daughter populations.

... "speciation" or subspeciation. ...

btw -- can you tell me (again?) what the difference is between these? Is it a necessary part of the description of the nested hierarchies here? It seems to me potentially confusing.

Are subspecies genetically reproductively isolated daughter populations?

Or physically reproductively isolated daughter populations?

Or not reproductively isolated daughter populations (ie - varieties)?

... But I don't think you'd find any genuine increase in the genetic variability anyway, so OK, yes, that would be a test.

And if we find no decrease in variability is that also a test?

If we find an increase in variation, is that a test? If we find a new variety and can show that it did not exist before ... is that a test?

I'm not sure why HOW the formation of a daughter population should change things. Migration of the new population to a new geographic area would accomplish the same thing, assuming reproductive isolation as well. In any case it depends on the numbers involved. ...

Indeed that would be similar. The difference would be the likelihood of both populations carrying all the then current alleles within their breeding members. This would mean no reduction in the populations without further selection to adapt to the different ecologies (even if they are fairly similar).

So yes it depends on the numbers.

... it should show a reduction in genetic variabilithy, but not right away ...

Why?

... At first if you checked individual genomes they'd have the same genetic variability of course. ...

Agreed. So what changes?

... It would take a few generations for the different gene frequencies in the two populations to show up ...

What changes in the variability?

We would expect some changes in the variations between the two populations as they adapted to the different ecologies, different challenges to survival and breeding. A change in the gene frequencies would be a change in the variations of phenotypes within each breeding population, not in their ability to vary.

... in the development first of many different phenotypes and then a recognizable new phenotypic character for the population as a whole, ...

But you are not saying that the ability to vary is changing, you are saying that the distribution of varieties is changing.

For a new phenotype character to emerge it would either need to be either recessive (rare rather than non-existent in the previous populations), suppressed (by a gene that is lost, either by selection or drift), or new (due to new mutations).

... and that's when I'd expect a reduction in genetic variability to start to become measurable.

And if we find no change in variability does that invalidate your hypothesis?

Curiously, I would expect no change in variability, but I would expect a change in varieties in both populations that are now isolated.


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This message is a reply to:
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 Message 144 by Coyote, posted 02-17-2014 11:52 AM RAZD has acknowledged this reply

  
Coyote
Member (Idle past 301 days)
Posts: 6117
Joined: 01-12-2008


(1)
Message 144 of 236 (719746)
02-17-2014 11:52 AM
Reply to: Message 143 by RAZD
02-17-2014 11:36 AM


... is that a test?
You keep asking, "... is that a test?"

The answer is -- maybe.

If the test results contradict someone's interpretation of the bible then its not a test, its an incorrect test, its a meaningless test, or its just wrong, somehow.

If the test results confirm someone's interpretation of the bible then its a test.

You keep trying to do science when science will be rejected at the point where it contradicts someone's interpretation of the bible.

Or...

You can lead a horse to water but you can't make 'em think.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

Belief gets in the way of learning--Robert A. Heinlein

How can I possibly put a new idea into your heads, if I do not first remove your delusions?--Robert A. Heinlein

It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers

If I am entitled to something, someone else is obliged to pay--Jerry Pournelle

If a religion's teachings are true, then it should have nothing to fear from science...--dwise1


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NosyNed
Member
Posts: 8848
From: Canada
Joined: 04-04-2003


(4)
Message 145 of 236 (719748)
02-17-2014 12:10 PM
Reply to: Message 141 by Faith
02-16-2014 6:04 PM


Clarity of Definitions
There's the Kind and then there are subspecies or variations on the Kind.

Am I correct to remember that you have agreed that, within a kind, there are populations (all of the same kind) that can not interbreed with each other? E.g., wolves and foxes of the dog kind.

As as been pointed out a number of times one biological definition of "species" is a population that breeds within itself but not outside. Thus a given wolf (e.g. maned) and a specific fox (e.g., fennec) are separate populations from a breeding point of view and therefore fit the definition of "species".

Since we all want to talk about such populations why can't we all use the word "species" instead of "subspecies", "variations", "subkind" or any other word?

It seems to me that, at that level, we are all talking about the same thing and have agreed on the existence of such populations. We certainly agree that tigers and housecats are not interbreeding populations don't we? We also agree that they originate from a population that did all interbreed, don't we? (Your view is that is the original cat kind of the arc and ours it that it goes back a little further but we otherwise agree, no?)

Based on that we all agree that the original population split into separate non-interbreeding populations. This is precisely the definition of a species.

Why not use it?


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AZPaul3
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Posts: 4259
From: Phoenix
Joined: 11-06-2006
Member Rating: 3.7


Message 146 of 236 (719770)
02-17-2014 9:54 PM


An Interesting Graphic

Source


Replies to this message:
 Message 147 by Faith, posted 02-18-2014 1:28 AM AZPaul3 has responded

  
Faith
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Posts: 32148
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 147 of 236 (719777)
02-18-2014 1:28 AM
Reply to: Message 146 by AZPaul3
02-17-2014 9:54 PM


Re: An Interesting Graphic
I am unable to read that page. It's hard on my eyes from the whiteness and the print is too small. I could probably make it readable but I'd have to have a good reason for doing that, if you could explain that to me. Thanks.

Edited by Faith, : No reason given.


This message is a reply to:
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Replies to this message:
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Taq
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Posts: 7971
Joined: 03-06-2009
Member Rating: 4.5


(1)
Message 148 of 236 (719797)
02-18-2014 10:52 AM
Reply to: Message 135 by Faith
02-15-2014 5:36 PM


But the problem is you aren't looking for reduction in genetic variability (not "viability"), which is why you have not "seen" it.

You are not looking for population specific mutations which cause the two subspecies to diverge over time, and increase variability.

We can use subspecies if you want. This would make chimps and humans subspecies of apes. Bears and humans would share a common ancestor and be subspecies of mammal. Trout and humans share a common ancestor and are both subspecies of vertebrate.

Using your definitions, all we need is the production of new subspecies and microevolution to produce the biodiversity we see today. If you don't want us to use macroevolution or species, we won't. Your terms as you define them are all that is needed for evolution to occur.


This message is a reply to:
 Message 135 by Faith, posted 02-15-2014 5:36 PM Faith has not yet responded

  
Taq
Member
Posts: 7971
Joined: 03-06-2009
Member Rating: 4.5


(2)
Message 149 of 236 (719798)
02-18-2014 10:58 AM
Reply to: Message 92 by Faith
02-14-2014 2:16 PM


Re: Genetic variability on the Ark
Not the same variability as a population, no, and I am aware that an explanation is needed for the many alleles in the population for some genes (ABE: though I have no idea what MHC refers to), which could not have existed on the ark.

But on the ark there could have been four different alleles for each pair or couple for many more genes than would have that many alleles today, though I'd have to suppose some attrition since the Fall, AND I'm sure this won't sit well, but if what is now junk DNA or pseudogenes was functioning DNA in the people and creatures on the ark, which I think very likely, then there would have been as much as 95% more genetic variability through that source than exists today.

What you have to remember is that every person is born with about 50 mutations, some of which are going to be in genes. Everyone is going to have 2 or 3 new alleles at the DNA level. These may not cause new phenotypic traits, but they will be genetic variations.

Also, MHC stands for Major Histocompatibility Complex and it is a set of genes involved in immunity. When doctors search for organ donors they are looking to match some of these alleles between one donor and recepient. Some of these genes have great diversity:

"The most diverse loci, namely HLA-A, HLA-B, and HLA-DRB1, have roughly 1000, 1600, and 870 known alleles, respectively."
http://en.wikipedia.org/.../Major_histocompatibility_complex


This message is a reply to:
 Message 92 by Faith, posted 02-14-2014 2:16 PM Faith has not yet responded

  
Taq
Member
Posts: 7971
Joined: 03-06-2009
Member Rating: 4.5


Message 150 of 236 (719799)
02-18-2014 11:00 AM
Reply to: Message 96 by Faith
02-14-2014 3:28 PM


Re: This thread should be about facts not interpretaions
Insisting on definitions does not belong on this thread. I'm a creationist and I have a different way of understanding the data than you do and your attempt to force it down my throat is unwelcome, especially on this thread.

At the very least, we should all strive to understand the other person's position. You can understand how the theory of evolution is applied in genetics without having to accept that evolution is true.

Edited by Taq, : No reason given.


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