Re: Why is it macroevolution?

r norman wrote:
On Sat, 12 Aug 2006 17:07:15 -0500, "Denis Loubet" <dloubet@xxxxxx>
wrote:

"r norman" <NotMyRealEmail@xxxxxxxxxxxx> wrote in message news:kfasd259jms908tuih9dfpu2j0droakvsf@xxxxxxxxxx
On Sat, 12 Aug 2006 17:44:42 GMT, pdunkel@xxxxxxxxxxxxxxx (Dunk)
wrote:

By definition it seems. In t.o. microevolution is defined as
population - level processes, or it is defined as only changes in
allele frequencies in a single population, or it is defined as
population genetics. These are not quite the same things, but each
leaves much left over to be macroevolution. In addition,
macroevolution seems to be, per various threads with 'rev. Goetz',
sometimes not a process but the reason(s) for various processes even
though they are population-level.

Elsewhere, macroevolution is defined as including any noticeable
morphological change.

Sticking with the t.o. version: suppose a species subdivides into two
populations, A and B. Perhaps B is a relect group left behind as the
species' range shrinks. B's environment changes. If population B
evolves into a distinct species, that's cladogenesis, or
macroevolution, unless A (the rest of the species) dies out first.
Then the change in B is anagenesis, or microevolution. It depends on
distant events.

The traditional biological definition is that microevolution is the
change in the genetic composition of a population. That is also the
technical definition of evolution, itself. Your alternative phrases,
"population level processes", "changes in allele frequencies in a
single population", or "population genetics" are not exactly the same
thing but all refer to the genetic composition (i.e. allele
frequencies) in a population.

Macroevolution refers to evolutionary changes that result in the
production of a new species or to a new taxon above the species level.

That is, microevolution refers simply to change; "descent with
modification" if you will. Macroevolution refers to branching in the
tree of descent.

That is the way most biologists describe it, although you can put in a
lot more technical details. What t.o. calls it is whatever anybody
who wants to post says.
My understanding is that it's not a biological term at all, it's a creationist term.

There is no such thing a micro and macro evolution, there's only evolution.

True, there is only evolution, but it can be divided into micro and
macro categories, rather distinct subjects that can be taught in very
distinctly different courses.

I wonder how many times people will repeat this until it sinks in.
OTOH, on the TO website, there is little if any mention of the distinction.

There is only chemistry, but still we
have organic and inorganic.

Absolutely, each with their own quirks and particularities. The people that have studied chemistry will know that many things cannot be explained by "mix 2 atoms/molecules together=more complex compound."

Do a google search restricted to academic
sites: "macroevolution site:edu" to find almost 70,000 hits.
Searching "microevolution site:edu" finds almost 44,000.

There you go.


That micro vs. macro evolution is purely a creationist construct is a
misunderstanding very common especially on t.o. And if you really
want an argument, raise the question of whether macroevolution is
nothing more than "a lot of microevolution piled high".

According to many in here, which I like to call the semi-learned or even the hardly-learned, it's all about accumulations of revolutionize changes, *period* as if every single mystery and process of life has been elucidated and this, under the light of the fact that we ignore/partially understand the role of more than 90% of the genome in any species.

There are
many biologists who argue that macroevolutionary processes require
mechanisms and events that surpass what microevolution considers.

And the theories of these biologists will probably rebuke the nonsense of accumulating microevolutive changes as the engine of "speciation" by mutations alone.

You
get into selection above the level of the organism and the role of
environmental change in shaping the structure of taxonomic groups and
all sorts of things.


--
Nicolas


"And, heaving alljawbreakical expressions out of Sare Isaac's universal of specious aristmystic unsaid, A is for Anna like L is for liv."
Finnegans Wake (293)

".... It means that all living things are the product of mindless material forces such as chemical laws, natural selection, and random variation. So God is totally out of the picture, and humans (like everything else) are the accidental product of a purposeless universe. Do you wonder why a lot of people suspect that these claims go far beyond the available evidence?" Phillip E.Johnson, The Church Of Darwin

.

Relevant Pages

  • Re: Macroevolution FAQ 2.1D
    ... Macroevolution - its definition, philosophy and history ... "microevolution" is, and by this they seem to mean that whatever evolution is ... evolutionary change at or above the level of species. ...
    (talk.origins)
  • Re: Macroevolution FAQ 2.1D
    ... > Macroevolution - its definition, ... > "microevolution" is, and by this they seem to mean that whatever evolution is ... > evolutionary change at or above the level of species. ...
    (talk.origins)
  • Re: Behe in the latest Protein Science
    ... >>species sorting or species selection. ... Microevolution is certainly involved but microevolution ... > increase in oxygen levels, chance, the evolution of evolvability, etc. ... That's what macroevolution is all about. ...
    (talk.origins)
  • Re: Why is it macroevolution?
    ... population - level processes, or it is defined as only changes in ... leaves much left over to be macroevolution. ... species' range shrinks. ... Then the change in B is anagenesis, or microevolution. ...
    (talk.origins)
  • Why is it macroevolution?
    ... allele frequencies in a single population, ... leaves much left over to be macroevolution. ... species' range shrinks. ... Then the change in B is anagenesis, or microevolution. ...
    (talk.origins)