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Author Topic:   MACROevolution vs MICROevolution - what is it?
RAZD
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Message 1 of 2 (385010)
02-13-2007 9:07 PM


This is the essence of the debate isn't it?
In several recent posts there have been the usual references to "macro"evolution and "micro"evolution:
EpicThought in Message 9
While I personally believe that evolution should be taught in schools (along with ID) I don't believe in any theory I have seen on macro evolution.
nemesis_juggernaut in Message 17
I believe there is a limit on the speed of beneficial evolution that hits a wall, which thus, would render evolution on a macro scale impossible.
Oliver in Message 196
The way I see it is that the whole of nature disproves macro-evolution but not micro-evolution. We simply cannot directly observe macro-evolution and if someone could provide an example I would greatly appreciate it.
where I have responded each time with a rather simple request:
Please define "macro"evolution - so we can be sure we are (a) talking about evolution and (b) we are talking about the same thing.
Also define "micro"evolution just to be sure we are talking about something different.
It should be easy eh?.
I think this and the current responses should be discussed in a new thread because it is fairly central to the whole debate and to keep other threads from going off-topic.
Response from EpicThought in Message 14
Please define "macro"evolution
evolution at the species level or above
Also define "micro"evolution"
evolution belowe the species level
Response from nemesis_juggernaut -- none to date.
Response from Oliver in Message 198
Micro, as in variation and adaptation.
Macro, as in complete change fronm one creature into another.
Thanks..
My response to Oliver is in Message 200, where I asked for further clarification of what were the limits on each "type" of evolution. The critical elements of the reply are:
Micro, as in variation and adaptation.
Do you mean all mechanisms of evolution that have been observed in the process of change in phenotype and genotype of a species population up to and including what is called "speciation" - using a standard biological species definition of non-breeding populations as a definition of species?
Macro, as in complete change fronm one creature into another.
How much change and in what time-frame?
In one sense this occurs at the moment of speciation: one species has become another. They no longer interbreed because they are different.
Or do you need the accumulated change from, say, two speciation events, to show that change is continuous and necessarily divergent rather than convergent? That second generation daughter (grand-daughter) species are more different from the original parent species than the intermediate ones?
... there's more to it, and so far there has been no response.
I will be moving my reply to EpicThought here to keep it out of the {Why should ID be taught in science classes...} topic discussion:
To EpicThought Message 14:
So when speciation has occurred it is due to "micro"evolution, and when that new species continues to evolve it is due to "macro"evolution?
That isn't saying much, nor is it any kind of problem for evolution and it matches the evidence we have already of continued evidence of evolution after speciation.
In essence once a second speciation has occurred then de facto "macro" evolution has been observed to occur.
We can look at the fossil evidence of foraminifa for instance:
Geology Dept article 3
quote:
Drs. Tony Arnold (Ph.D., Harvard) and Bill Parker (Ph.D., Chicago) are the developers of what reportedly is the largest, most complete set of data ever compiled on the evolutionary history of an organism. The two scientists have painstakingly pieced together a virtually unbroken fossil record that shows in stunning detail how a single-celled marine organism has evolved during the past 66 million years. Apparently, it's the only fossil record known to science that has no obvious gaps -- no "missing links."
"We've literally seen hundreds of speciation events," Arnold added. "This allows us to check for patterns, to determine what exactly is going on. We can quickly tell whether something is a recurring phenomenon -- a pattern -- or whether it's just an anomaly.
Thus we have observed "macro"evolution.
This also means that no other mechanism is needed for "macro"evolution to occur than is needed for "micro"evolution -- the continued evolution within each differentiated species -- and thus there is no barrier to "macro"evolution to continue to happen and increase the differentiation between the species as time passes.
This also matches what we see in the fossil record.
(note to admins & others: The above reply will be deleted from the ID thread when this topic is promoted).
This is the essence of the debate: when does change become sufficient to be "macro"evolution and how does it occur.
What is the difference between "genus" "family" "order" and all those other taxonomic classifications? When does one become the next level? What is the change that is involved?
Enjoy.

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Message 2 of 2 (385023)
02-13-2007 10:11 PM


Thread copied to the MACROevolution vs MICROevolution - what is it? thread in the Biological Evolution forum, this copy of the thread has been closed.

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