RE: [asa] (fruit flies???) A Message from the RTB Scholar Team

From: <kbmill@ksu.edu>
Date: Tue Apr 22 2008 - 14:56:52 EDT

Bernie:

> Sounds like you are referring to what YEC's call "micro evolution."
> I
> think if we really understood evolution, we should be able to do
> "macro
> evolution" also in the lab... such as creating new creatures; since
> we
> can do the same thing nature does, only much faster when directed by
> intelligence (we can measure, screen, and control populations of
> animals
> that reproduce rather rapidly).

Speciation IS macroevolution. The most common demarcation between
"micro-" and "macroevolution" in the literature is speciation.
Microevolution refers to processes at the population level within
species. Speciation and the patterns of speciation in time are the
subjects of macroevolution.

The patterns of diversification of species in time is something that can
only be studied as part of the record of the history of life as
recorded in the anatomy of living species and in the fossil record.
The classification of higher taxonomic categories is simply that --
classification. The evolution of a new higher taxon can only be
recognized in retrospect. Typically the character traits that
distinguish a particular taxon from other closely-related taxa are
quite subtle and are only recognized as important because of the
subsequent evolution of species with that particular trait. For
example, the first reptiles with a dentary-squamosal jaw joint were
unremarkable at the time, yet that feature is a defining characteristic
of what we call mammals.

Classification is one means to describe the diversity of life and its
historical record. Cladistics is one of the dominant approaches to
classification used today. I discuss the role of classification in the
chapter on transitional forms in "Perspectives on an Evolving Creation"
-- you can go there for a more thorough discussion.

My point here is that species are real biological entities (at least as
understood by most biologists and paleontologists). However, the
definition of higher taxonomic groups is the construction of artificial
categories to aid in our description of the diversity and relatedness
of life.

The evidence for common descent is overwhelming. That evidence is from
a wide range of sources including the fossil record, genetics,
comparative anatomy, and development. Transitional forms are a common
occurrence in the fossil record and cross the boundaries of all the
major levels of the taxonomic hierarchy.

Keith

To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Tue Apr 22 14:58:24 2008

This archive was generated by hypermail 2.1.8 : Tue Apr 22 2008 - 14:58:24 EDT