Evolution Requires Reduction in Genetic Diversity

Indeed. Dawkins described evolution as a drunken stagger. It is a two-step feedback response system that is repeated in each generation: Like walking on first one foot and then the next.Mutations of hereditary traits have been observed to occur, and thus this aspect of evolution is an observed, known objective fact, rather than an untested hypothesis.Different mixing of existing hereditary traits (ie Mendelian inheritance patterns) have been observed to occur, and thus this aspect of evolution is an observed, known objective fact, rather than an untested hypothesis.Natural selection has been observed to occur, along with the observed alteration in the distribution of hereditary traits within breeding populations, and thus this aspect of evolution is an observed, known objective fact, and not an untested hypothesisNeutral drift has been observed to occur, along with the observed alteration in the distribution of hereditary traits within breeding populations, and thus this aspect of evolution is an observed, known objective fact, and not an untested hypothesis.Thus many processes of evolution are observed, known objective facts, and not untested hypotheses.Enjoy

This has the potential to create a great deal of confusion as it seems contradictory. How can you accept selection when it involves reduced genetic diversity but reject selection in all other contexts? Why would selection operate differently upon a trait depending upon the genetic process that produced the trait?

Yes, it was addressed. Put simply, through analysis they identified the specific gene and the changes to the gene that provided the Swedish population with freeze tolerance, then they checked their analysis by inserting the Italian version of the gene into a Swedish population and observed that freeze tolerance was lost.HBD's point was that these are the types of changes one would expect as different populations of the same species experience different mutations and different selection pressures.

One the gene pool has run out of variability it is at a dead end.And if it hasn't, and acquired more genetic diversity after forming a species or subspecies, as I keep saying, that produces only scattered new traits, it still has to be subjected to the processes that reduce genetic diversity in order to arrive at a new species or subspecies. Edited by Faith, : No reason given.

In this case it must be natural selection, different versions showing up and the adapted one surviving, but nothing was said to prove it was a mutation.Edited by Faith, : No reason given.

HBD didn't just declare that it's complex, he actually presented the data to you. You dismissed it claiming it was too complex for you to understand.Instead of dismissing what you don't understand, it would greatly improve discussion if you would instead work to understand it.

What would greatly help these days is being a lot less subjected to advice, rules and other comments,.

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Read much?"So they sequenced this gene (named CBF-2) and found that the Italian population had a deletion of 13 nucleotides which resulted in a stop codon and a truncated protein (sound familiar?). When they inserted the Italian CBF-2 allele into a Swedish genetic background (all other loci were of Swedish origin except the Italian CBF-2 allele) the plant lost its freeze tolerance. SO we have a Swedish CBF-2 allele that helps the plant tolerate freezing temperatures and an Italian CBF-2 allele that does not have freezing tolerance."A deletion of 13 nucleotides is a mutation.

Let me simplify HBD's point. There's a species with a main population A and an isolated subpopulation B. Consider just one gene of this species that has alleles R, Q and S, but the S allele is missing in subpopulation B. That means the populations have these possible combinations of alleles for this gene: Notice that population B has no allele combinations that do not exist in population A. Expressed another way, every allele combination of population B already exists in population A.Given this information, it would be very helpful if you could answer this question: Naturally it would also be very helpful if you could clarify whether you think speciation is even possible with your reduced genetic diversity approach. Everyone else already knows the answer is no, they're just waiting for you to arrive at the same conclusion.And once you do understand that just mixing the same old alleles into new combinations cannot create genetically new species, it should also help you understand the problems with your claim that reduced genetic diversity is how evolution works. Biologists already understand that reduced genetic diversity by itself cannot create a genetically new species, so they would never propose or even consider it as the way evolution works.AbE:I should have commented about this: Here is the diagram HBD provided earlier: And here is the description HBD provided in Message 721: So no, population B is not a daughter population of population A. But in his example HBD addresses the alleles of a specific gene to illustrate how impossible it is, at least with respect to this gene, for population B to become genetically different from population A.Edited by Admin, : AbE.

Some of it is mutation, some of it is developmental effects on the maturation of the zygotes, and some of it is the random pairing of parental genes, one from column dad, one from column mom. Mutations include places where DNA strands are moved from one site to another or where some sections are omitted or where some sections are duplicated. They are random, in part because replication is an imperfect process and in part because replication can be affected by environmental aspects (heat, chemical, hormonal). Adaptation is a two fold process the introduction of variation by mutation and selection of those variations that are better able to survive and reproduce: Adaptation tends to be habitat\ecology specific (survival success) and mating specific (reproduction success). With runaway sexual selection (peacock) you can have remarkable adaptation with no change in habitat\ecology. We do see a degree of sexual selection in humans with mating preferences and race, but not enough to lead to mating isolation. When selected alleles in one group (beneficial in it's habitat\ecology for survival and reproduction), happen to be incompatible with the selected alleles in the other population (beneficial in their habitat\ecology for survival and reproduction). Differences are not necessarily incompatible, but it can arise when there is no gene flow between the populations during the period of isolation. Sorry, I meant reacquainted -- when the two populations that have been isolated happen to come back together, and in American natives and European explorers, or the two northern varieties of the Asian Greenish Warbler. As in the Asian Greenish Warblers, a commonly used term is varietal or variety, as that implies differentiation between the populations but still being the same species. Race is also used, but to a lesser extent (perhaps because of negative connotations from racial discrimination). And in the absence of evidence to the contrary the assumption of continued genetic diversity and replenishment via mutation and selection is reasonable, especially as there IS evidence that this occurs. It's not a process that occurs all in one generation. As we see with the Cheetah the bottleneck was fairly recent (~12,000 years ago), the population that survived was small, the reproduction rate is low, cheetah populations are fairly isolated, meaning less opportunities for new mutations to occur and then work their way into the breeding population. Or it just hasn't happened yet. And the next generation would have a scattering of more new traits, and the next generation would have a few more ... over time if these traits are beneficial to survival or reproduction or neutral to selection they will spread through the population. Thus the new traits build up over time, each generation building on the new traits from the last generation. It isn't an ability of the species Faith. Mutations occur randomly and there is no known process that prevents it. Mutations occur, and whether they are beneficial\neutral\deleterious depends on the habitat\ecology (survival) and on sexual compatibility (reproductively viable). And again, mutations occur randomly and there is no known process that prevents it. Mutations occur, and whether they are beneficial\neutral\deleterious depends on the habitat\ecology (survival) and on sexual compatibility (reproductively viable). If you can't get enough in one generation, then you look at two generation, three generations ... 50 generations ... 100 generations ... it is an accumulative process and not an all at once process. Not necessarily. You can have two populations with the same genetic diversity becoming isolated in different habitats\ecologies. What happens during the accumulation of new traits and their selection in those habitats\ecologies is what determines whether they become different species or not. Sometimes yes, sometimes no. Mutations and selection occur, they have been observed. Speciation occurs and it has been observed. That is not conceptual, it is fact. That IS evolution. Mutations are random, they are not "on demand" or occur for a purpose, but there is no limitation on mutations happening. That produces an endless supply of variations for selection to act on.Neither does selection lead to any other purpose than the ability of individuals to survive and reproduce, there is no purpose to increase genetic variability or to produce new species, they are just occasional results of evolutionary processes. That endangered species are in danger of going extinct does not mean that evolution does not occur. The natural history of organisms shows that over 99% of species go extinct. That is part of the selection process, occurring at the species level rather than the individual level. You can think of every breeding population as an "individual" species that evolves to increase it's ability to survive, and the "individual" species that are best at survival will supplant those that are less viable.Evolution won't stop or the world come to an end if the cheetah and other endangered species perish and become extinct, rather there will be species that survive and there will be new species that develop from those living species, as has occurred throughout the natural history of life on earth.Evolution does not exist to preserve species. Because it doesn't do what you think it should do is no reason to think it is conceptual\fiction\etc, Faith, rather it is your narrow misunderstanding\expectations that are what fail.Enjoy

Please respond to my Message 852.

Thank you for the correction, although it was unnecessary. The number I posted was directly quoted off the site I was on ... I just deleted the math in between.My point was that only 128 variables of on/off allow for almost unimaginable number of variations. The proportional increase of variations based on the gene and alleles numbers is virtually infinite. Even if each genetic change that led to a new species was permanent (which it isn't), there is infinitesimal diminishing of the possibility of future changes within the lifespan of planet Earth.But you pointed out that your correction wasn't about the point I was trying to make. I just realized that ... but I am too lazy to erase what I typed in above.Edited by mikechell, : lack of earlier observation.

Does evolution require a reduction in genetic diversity? Yes. (Well, technically it's not required... but realistically-practically... it's going to happen).Does evolution require an increase in genetic diversity? Yes. (Again, technically no... but without it, all things would die rather quickly).The only question is: Which is greater? What is the net result?Does evolution require a net reduction in genetic diversity? No.
Does it happen? Yes.
When it happens continuously, creatures die off. This has happened, does happen and will continue to happen many, many times.Does evolution require a net increase in genetic diversity? No.
Does it happen? Yes.
When it happens continuously, creatures flourish. This has happened, does happen and will continue to happen many, many times.The facts are that both these situations happen at different paces to different groupings of creatures all over the planet.
Some are lucky and flourish, others... not so much.
It should also be noted that any particular, specific increase or decrease in genetic diversity really says nothing about any overall net increase or decrease on the populations in question.Edited by Admin, : Add emphasis around "net".

I haven't been providing you "advice, rules and other comments."I've been requesting clarification of some points, and I've been providing clarification of some points made by others. Yes, most of this is related to you, but I do the same with everyone, as I did with NoNukes earlier today, and with HBD earlier in the discussion.In many messages people complain that they can't make sense of what you're saying, and you keep complaining that no one understands what you're saying, so I'm trying to help discussion along by asking you to provide clarification about some of your key points.Also, you can't dismiss evidence because it is too complex to understand, then complain when someone else merely says it's complex because they know that if they describe the evidence you'll complain it's too complex. This makes no sense. Please work to understand the evidence. No one has ever judged a debate saying, "Because side A couldn't understand the evidence and arguments from side B, side A wins."Edited by Admin, : Grammar.