"Macro" vs "Micro" genetic "kind" mechanism?

Hi again Ichiban, One of the problems here is what is meant by "macroevolution" ... if Coyote is talking about speciation and you are talking about sudden transformation, then you will inevitably disagree ... while you can both be right.see MACROevolution vs MICROevolution - what is it?:

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Please define "macro"evolution - so we can be sure we are (a) talking about evolution and (b) we are talking about the same thing.

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Also define "micro"evolution just to be sure we are talking about something different.

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It should be easy eh?.

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I'll just note that the definitions, as used in biological evolution science, are that "microevolution" is the evolution - the change in hereditary traits in populations from generation to generation - that occurs within a species, while "macroevolution" is the development of a tree of common ancestry by speciation - the division of an ancestral population into two or more reproductively isolated daughter populations - (causing branches in the tree) and evolution - the change in hereditary traits in populations from generation to generation - of each branch species independently of all the others.References:
(1) Berkeley U. website, Evolution 101
(2) U. of Mich website, Evolution and the Process of Speciation and Evolution and Natural Selection
(3) Talk Origins website, What is Evolution? (references some other definitions)Based on these definitions macroevolution involves speciation and microevolution, both of which are observed actual processes.Of course, the fact that species have been observed also means that there is no genetic barrier to the development of new species as reproductively isolated sibling species continue to evolve along different paths within different ecologies.Once you realize that this is what is meant by "micro" and "macro" within the science of evolutionary biology, and that no other mechanisms are necessary to explain the diversity of life we see - in the world around us, in history, in prehistory, in the fossil record and in the genetic record - then you may understand that there is no genetic barrier to macroevolution.If you are going to argue a different definition for "macroevolution" (as many creationists do) then realize that you are talking about something else, something that may very well never have happened. However then you are not arguing against evolution, but that "other" definition. Message 206
Speciation and nested hierarchies. These confirm macroevolution according to the usage of evolutionary biological science.Again, if you are using a different definition of "macroevolution" then you are talking about something NOT{evolution}.Enjoy. Edited by RAZD, : added response at endEdited by RAZD, : ps

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Thank you Ichiban, I note that you have not provided an alternative definition for macroevolution to what I presented to you. Good, that means we agree on the term applying then to speciation and the formation of nested hierarchies of relationships, and not to any necessary large scale degree of change in either species.And again, what your opinion is does not matter, it does not change reality, it does not cause speciation to suddenly stop or the fossil record to change.This is speciation in the fossil record of Pelycodus: Three different speciation branches from the main trunk, animals that went on to form basic types of primates, btw ... including humans. Ring species are good example of incipient speciation, of finding the minimal difference necessary for division of a parent population into reproductively isolated daughter populations. There are other examples of more complete speciation, especially in plants. That there is no barrier is demonstrated by convergent species, like the sugar glider and the flying squirrel: nothing prevented them from evolving such similarity to fill a similar ecological niche.What this means is that the concept of a barrier that would prevent such evolution is invalidated, demonstrated to be a false concept.The sun has been found to be the central core of the solar system, around which the earth and the other planets orbit. We could say that this is only what has been observed to date, but that would be rather silly.Enjoy.Edited by RAZD, : silly

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Thank you Ichiban, Good, common understanding is important to honest debate.Let me add to what Modulus has already pointed out. The question is not what has NOT happened according to evolution. The question is whether there is a genetic barrier that prevents one kind from evolving into a different kind. Message 1

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IF the concept of "kinds" is correct, THEN there must be mechanism(s) in the DNA that allows "micro"evolution but prevents "macro"evolution?

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All of these examples are evidence of already existing animals that, it could be argued, have already "broke out of the niche went beyond it in an evolutionary sense" and become something different from their non-gliding cousins. Snakes are not mammals are not frogs are not reptiles are not fish, but all of these "kinds" of animals also have some that have evolved the ability to glide, with no genetic barrier preventing this from happening.It is, however, the examples of convergent evolution that unequivocally show that any kind can evolve to be similar to another kind.Simply put, if a placental squirrel can evolve into a flying squirrel, and a marsupial possum can evolve into a sugar glider, a lemur can evolve into a colugo, and they have all evolved into similar organisms, there is no barrier to this evolution.Simply put, if a placental shrew-like mammal evolved into a bat, a dinosaur evolved into a bird, another to a pterosaur, and they have evolved into similar organisms, there is no barrier to this evolutionSimply put, if a warm-blooded true-boned hoofed mammal evolved into a killer whale and a cold-blooded cartilaginous fish evolved into a white shark, and they have evolved into similar organisms, there is no barrier to this evolution.This is not "what if" thinking of what someone thinks could or even should evolve, this is actual factual evidence of what HAS evolved. Without barrier. A cow became a fish, a reptile and a mammal became a bird.It is not a matter of their having "broke out of the niche went beyond it" but of their evolving to fill the same niche from a number of different evolutionary paths, unencumbered by any barrier in their genetics that prevents such evolution.Enjoy.

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The first thing necessary to answer this question is what you think macroevolution means.In the science of evolutionary biology macroevolution is speciation and the formation of nested hierarchies of organisms related to a common ancestral population.The process that causes speciation is what is normally called microevolution -- the change in hereditary traits in populations from generation to generation -- however this same process is going on in two or more populations of a parent species, with reproductive isolation such that traits in one population are not shared with another population. This results in an increase in differences in the selection of traits that arise through mutation and that are selected for their benefit to survival and reproduction in the different ecologies for the different daughter populations.Once two or more populations are reproductively isolated, there is no mechanism to homogenize the genetic pools between the daughter populations. They will each continue to evolve, and in each case this evolution will be to adapt to different ecologies, and thus increasing divergence is basically inevitable.These daughter populations become parent populations when their populations diversifies into different ecologies, and the whole pattern repeats.That is the process that causes speciation and the formation of nested hierarchies, and thus what evolutionary biologists consider macroevolution.Over time this same basic process is capable of evolving from a marsupial ancestor to a sugar glider and from a mammal ancestor to a flying squirrel Thus we see no genetic barrier to what can evolve, instead we see adaptation of existing traits and variations on a theme provided by mutation for selection to take advantage of opportunities to adapt to an ecology in order to survive and reproduce.Your turn.Enjoy.

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Black,This: Is entirely different from your previous post, and totally irrelevant to the topic.This: Message 235
Is different from your original message 235 (posted 02*25*2009 02:41 AM and replied to on 02*25*2009 07:34 AM): It appears that my last reply was wasted on you. I also note that you still have not addressed what you think "macroevolution" involves, so if you want to continue a debate here, this is your homework assignment:To reply to this thread, and be on topic, define what you think "macroevolution" involves.Enjoy.Edited by RAZD, : post times and dates added

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An example of this is how easily artificial selection can take a population, say of wolves, and through selection and isolation develop breeds, in this case of dogs, where the different breeds are quite distinctive, and none of the traits of the various breeds exist within the population of wolf traits: As long as each breed remains reproductively isolated there will be no mixing of genes and thus no intermediates. Where interbreeding does occur (mutts) you see an absorption of the extreme variations of the breeds back into a generic "mutt" dog mixture, and a loss of the more deleterious forms and less viable forms through natural selection.Enjoy.

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You are going to have to define what you mean here by "sliding scale" versus what actual biological evolution shows. Why is life all settled in niches instead of being so settled in niches? You don't make sense. Really? Have you read Darwin, and why he said - predicts - that there would be no living examples of transitional series? It's called natural selection, where the better fit forms squeeze out the old less fit forms. Ring species would be one example, the effects you can get by selective breeding and reproductive isolation would be another example. The whole diversity of life into all the various niches is another example -- the complete example of species forming nested hierarchies of traits as they blend from one environment into another. Except that evolution is a process that occurs over generations, not mealtimes:Evolution is the change in hereditary traits in populations from generation to generation.It does not occur in individuals, as each individual organism develops according the the genetic pattern it has inherited. And the fact that there aren't, adequately demonstrates that your claim that there should be is false. Good. Now the question is, do you want to see whether it is your understanding that is false or evolution?First off, we should define what is meant by "transitional" species or forms between species.I'll go first:A transitional species is one that shows traits intermediate between ancestral populations and more modern ones. They share some traits with all populations, some traits only with ancestral form and some traits only with the derived modern form/s.Thus transitional species show the hereditary lineage from the original form through the intermediate form/s to the to the final form, as new traits are acquired that increase fitness, and old traits are discarded that no longer assist fitness.Next we can ask why the intermediates aren't as viable as the later forms: Evolution and Natural Selection

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Stabilizing, Directional, and Diversifying Selection

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Under stabilizing selection, extreme varieties from both ends of the frequency distribution are eliminated.

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Under directional selection, individuals at one end of the distribution of beak sizes do especially well, and so the frequency distribution of the trait in the subsequent generation is shifted from where it was in the parental generation (see Figure 6b).

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Under diversifying (disruptive) selection, both extremes are favored at the expense of intermediate varieties (see Figure 6c).

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Note that in every case selection favor one set of traits over others, thus you do not get an ever increasing variety of traits within a species.Your turn.Enjoy.Edited by RAZD, : ,Edited by RAZD, : clarityEdited by RAZD, : more clarity

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