Does microevolution logically include macroevolution?

This topic may have already been discussed in the past ad naseum, so if Admin. wants to reject it on the grounds of staleness, I certainly understand.I don't know a lot about TOE, so the claim I am making is very tentative. With this topic, I am here to be instructed more than to argue.But here's my idea:The system of labelling various life forms by dividing them into different species is merely a classificational scheme and is not meant to set forth the idea of essential characteristics of any given species. It is difficult to pinpoint along some evolutionary line precisely when a new species appears. I suppose in the past classification schemes were based on physical characteristics until somebody decided it made more sense to classify according to isolated gene pools. But even with this scheme, there appear to be some exceptions (dogs/wolves), which shows us that the classification scheme is merely a convenience, though perhaps the one that makes the most sense.So what happens is that the life form continues to change and after a while one group of life forms becomes insolated in terms of breeding from another group. When this isolation occurs, for whatever reason, the two groups continue to evolve separately and after a long time we can notice a difference in physical traits.The distinction between "microevolution" and "macroevolution" sounds fishy to me. Isn't all evolution "microevolution" since the changes are so gradual? It's not like there's some definite line of demarcation that is crossed where what was microevolution suddenly becomes macroevolution, is there? There are just these continuous small changes, caused by imperfect replication and mutation, and influenced by the environment, and this gradual change has to be continuous.There is no logical reason for the changes to stop within a certain circle of possible changes beyond which the life form cannot change--at least not that I can see.I conclude, therefore, that if you accept microevolution you also have to accept macroevolution.This message has been edited by robinrohan, 06-13-2005 01:38 PMThis message has been edited by robinrohan, 06-13-2005 01:40 PMThis message has been edited by robinrohan, 06-13-2005 01:44 PMThis message has been edited by robinrohan, 06-14-2005 04:44 AM

The whole concept is a little slippery to me. A species is defined as an isolated gene pool. But how did the life form get isolated? If we are talking about geographical isolation, then that in itself hardly seems enough to call it a separate species.Which comes first, the isolation of the gene pool or the physical changes?

The evidence contradicts what view?

So given enough time, anything can evolve into anything, I guess.But would you say that microevolution automatically leads to macroevolution--unless, of course, a life form dies out?

I see what you're saying, I think. Given a simple life form, the possibilities for change are much greater than if we "start off" with a complicated life form, which already has restrictions built in. I was thinking that, in a logical sense, it must because it is bound to change--that is if we assume imperfect replication.

And you call yourself "EZscience"! But I think I picked up the main drift. If we concentrate on sexual, not asexual species, isolation occurs before physical changes, and there are various ways a life form can be isolated (geographical, behavioral, or change in physical environment, like a new food). After a period of time in isolation, we can label this group a "new species." Why would not all microevolutionary changes necessarily lead to macroevolutionary consequences, given enough time? What's to stop the process of change?

This seems odd. What if you had some black bears in Oregon and some other black bears of exactly the same type in Vermont and never the twain do meet? Sometime in the past they got separated due to a flood or something. But it wasn't very far in the past. According to this definition they are separate species, I suppose.Everything else you've explained makes perfect sense to me. Just because you have changes due to imperfect replication, this does not mean that such changes are evolutionarily significant.But there was something else I was wondering about: Might an argument be made that mutations must occur, that they are built into the very process of reproduction?

This is different from what I've heard before, which is that species are separated by the fact that they don't interbreed, not that they can't.You're saying that the deciding factor is that they can't.So "theoretically" a big dog can mate with a little dog and therefore they are all the same species.As far as the rest of your post, I'm going to have to study it a little while. It has terms I'm not familiar with, like "meiotic reductions of germ cells to the haploid state." Now there's a mouthfull!

No, I won't.All this is rather difficult but I will study it.

I thought it meant that when a new species appears, this is macro-evolution. And I thought that if there are changes within a species but not enough to make it a new species, then that was microevolution.However, the definition of a species is that it has an isolated gene pool, not that it is different from some other life form in the sense of physical traits. What matters is whether it can get it on with this other group in the sense of producing offspring. If it can't, it is a different species from that other group.But according to easy-science, it's not a matter of whether you produce babies but if you are capable of producing babies.So it all comes down to sex.This message has been edited by robinrohan, 06-15-2005 11:09 PM

Thanks. I found it. Message #16. In reference to "People who tell the truth" subtopic below.This message has been edited by robinrohan, 08-01-2005 05:14 PM