Summations Only

Hi zi ko, The formation of novel traits, which begins the process of increasing the diversity within living species, that leads to phyletic speciation, and can lead to divergent speciation and the increase in the diversity of species on earth:

quote:

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(From my proposed thread Introduction to Evolution, Message 1): If we look at the continued effects of evolution over many generations, the accumulation of changes from generation to generation may become sufficient for individuals to develop combinations of traits that are observably different from the ancestral parent population. This lineal change within species is sometimes called phyletic change in species, or phyletic speciation. This is also sometimes called arbitrary speciation in that the place to draw the line between linearly evolved genealogical populations is subjective, and because the definition of species in general is tentative and sometimes arbitrary.
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(2) The process of divergent speciation involves the division of a parent population into two or more reproductively isolated daughter populations, which then are free to (micro) evolve independently of each other.

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The reduction or loss of interbreeding (gene flow, sharing of mutations) between the sub-populations results in different evolutionary responses within the separated sub-populations, each then responds independently to their different ecological challenges and opportunities, and this leads to divergence of hereditary traits between the subpopulations and the frequency of their distributions within the sub-populations.

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Over generations phyletic change occurs in these populations, the responses to different ecologies accumulate into differences between the hereditary traits available within each of the daughter populations, and when these differences have reached a critical level, such that interbreeding no longer occurs, then the formation of new species is deemed to have occurred. After this has occurred each daughter population microevolves independently of the other/s. These are often called speciation events because the development of species is not arbitrary in this process.

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If we looked at each branch linearly, while ignoring the sister population, they would show phyletic change in species (accumulation of evolutionary changes over many generations), and this shows that the same basic processes of evolution within breeding populations are involved in each branch.

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The "the accumulation of changes from generation to generation may become sufficient for individuals to develop combinations of traits that are observably different from the ancestral parent population" is the formation of novel traits, the topic of this thread.Remember that mutations affect the genotype and selection (ecological or sexual) operates on the phenotype (the expressed traits of the individuals), that it is a two-step dance, and not just hopping along on one leg. And I can agree with that, as working hypothesis.It has always seemed to me that evolution just shows the how of the process: that science, in general does not, cannot, really address the whys (purpose\causal\intent), because of the way science is formulated -- not because there is any intended attempt to eliminate it from science, philosophical or theistic consideration, but because science is just not capable of addressing those issues.EnjoyEdited by RAZD, : formatEdited by RAZD, : more formatEdited by RAZD, : clrty

Hi zi ko, Yes, but you will need to start a new thread for it, that would not add to the debate here and my thread has not been (and not likely to be) opened for discussion (admin and I are considering different or new options for this kind of thread). And this would be discussed on your new thread, yes? I'd be interested, if you choose that path.Enjoy.

Hi Tangle,How about a review of where we got to on the lizards and mice, what the problems were, and maybe some suggestions of where to go.This would be a reinstatement of the topic to bring it back in line, and then Percy can enforce strict adherence to that statement.Enjoy.