Micro vs. Macro continued

[Administrator: Two emails came in today with this subject. They are presented here in the order of their arrival. The second one is not a response to the first.]

HELEN

A number of times it has been claimed that macroevolution is
speciation. I and others have tried to point out that speciation is a
variable concept depending on the mating cues of the animals involved
and is therefore not a reliable pointer genetically or physically.
From the glossary, p. 637, of Mark Ridley's undergraduate textbook
Evolution, Blackwell Scientific Publications, Oxford, 1993:

"Macroevolution: Evolution on a grand scale: the term refers to
events above
the species level; the origin of a new higher group, such as the
vertebrates, would be an example of a macroevolutionary event."


In other words, creationists were NOT making up that definition.

 

KEVIN KLEIN

A new paper published by scientists at UCSD provides tantalizing new
evidence of possible mechanisms for evolution. Some selected quotes
from the news"]http://ucsdnews.ucsd.edu/newsrel/science/mchox.htm]news
release[/URL]:
<BLOCKQUOTE>quote:</font><HR>Biologists at the University of California, San Diego have
uncovered the first genetic evidence that explains how large-scale
alterations to body plans were accomplished during the early evolution
of animals.

In an advance online publication February 6 by Nature of a paper
scheduled to appear in Nature, the scientists show how mutations in
regulatory genes that guide the embryonic development of crustaceans and
fruit flies allowed aquatic crustacean-like arthropods, with limbs on
every segment of their bodies, to evolve 400 million years ago into a
radically different body plan: the terrestrial six-legged insects.

The achievement is a landmark in evolutionary biology, not only because
it shows how new animal body plans could arise from a simple genetic
mutation, but because it effectively answers a major criticism
creationists had long leveled against evolution-the absence of a genetic
mechanism that could permit animals to introduce radical new body
designs.<HR></BLOCKQUOTE>

For those interested, the actual paper is published
http://www.nature.com/cgi-taf/dynapage.taf?file=/nature/journal/vao
p/ncurrent/index.html]here[/URL].



[Administrator: Helen also posted this article in the media thread, with a response from Discovery Institute.]

 

RUFUSATTICUS

Before the waters get too muddy, I would like to clarify the differences
between macroevolution and microevolution. Macroevolution and
microevolution actually refer to the same biological process,
evolution. What differs between them is the frame of observation.
Macroevolution refers to differences between species. It is mostly
reflected in morphological changes exhibited in the fossil record and the
differences between extant taxa. Microevolution refers to differences that
occur within a species. It is mostly reflected by biological studies
conducted on extant populations of organisms. This distinction is mostly
due to different fields working on the same thing and having different
perspectives. The terms reflect the bimodal origins of Evolutionary
Biology. At one point in history the distinction was very much important
because some scientists argued that the mechanisms for intra-species
differences and inter-species differences were fundamentally different.
However, it became apparent as science progressed that macroevolutionary
differences are actually the result of the accumulation of microevolutionary
differences. The following thread also discusses the relationship between
the terms.
http://www.baptistboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=36&t=0001
14

Again, don't take my word for it; read the literature for yourself and
consult an evolutionary biologist (like me).

Finally here are my preferred definitions.
Evoltion: The heritable change in a population's traits over
time/generations.
Microevolution: Evolution apparent within a population or species.
Macroevolution: Evolution apparent between population or species.

-RvFvS

 

CRAW4RD

The following definitions come from the the book,
From So Simple A Beginning, The Book Of Evolution.
by, Philip Whitfield
who is an evolutionist.

<BLOCKQUOTE>quote:</font><HR>Macro-evolution,
The evolution of new species and the large scale patterns of evolution
above species level.

Micro-evolution,
The small genetic changes that take place in populations within a single
species. These changes represent the replacement of particular genes by
similar genes already present in low numbers in the population. <HR></BLOCKQUOTE>

I have often thought that speciation has been included in the
macro-evolution definition so that those who subscribe to evolutionism
can claim they have proof of macro-evolution.
My own personal opinion is that an animal must be considered as a
represenative fom a new taxonomic ranking of genus or and what I
consider the main qualifier is to develope or modify a new or existing
body part to the point inwhich is serve a new and useful purpose.

Craw4rd

 

PATRICK PARSON

If that's the standard, then the Institute for Creation Research admits
macroevolution exists. They endorse Woodmorappe's "Ark Feasibility Study",
in which he admits new species, genera, and families exist.

Most creationists have retreated to macroevolution as meaning new orders of
organisms. They don't have much more room; all that's left is class,
phylum, and kingdom.

 

HELEN

Everyone's own opinions aside, Futuyma seems to be a recognized expert
by the evolutionists here on this board, so this is from him:

Macroevolution: A vague term for the evolution of great phenotypic
changes, usually great enough to allocate the changed lineage and its
descendants to a distinct genus or higher taxon.

Futuyma, D.J. 1998. Evolutionary Biology. 3rd Ed. Sinauer
Associates, Inc. Sunderland, MA. (glossary)