Greetings Paul,
It would be good to sit down and chat with you sometime. Make sure you
call me up the next time you pass through Colorado.
I've asked this question before but you've never answered it to my
satisfaction.
Let admit the possibility of polyphyly and focus our attention on
branches/bushes a little higher up. Now does the genetic evidence and the
known mechanisms of modern, metazoan lateral transfer suggest that all
insects are descended from a common ancestor (or ancestral population)?
How about all arthropods?
How about all marsupials?
I can see why the "new" evidence is confusing with respect to the very
ancient lineages and this is very, very interesting. But is it really so
confusing with respect to metazoan sequences? I don't get that picture at
all in reading the literature, if anything the genomic arguments for are
sewing up rather nicely the arguments for common ancestry. The paper in
Science about a year ago on large scale chromosomal mapping giving
tremendous insight into the relationship between various mammalian orders
is a prime example.
I just think that you are mixing apples and oranges when you bring in all
the lateral gene transfer stuff from bacterial genomics into these
discussions of common ancestry of animal phyla and/or classes. Doolittle
and company may find the task of reconstructing lineage well-nigh
impossible by these new findings, but I serious doubt if any of them are
ready to suggest that evolution (change through time via "ordinary"
biological mechanisms") hasn't occurred.
Does your critic of this methodology undermine DNA fingerprinting as a
forensic method? How about in studying human or livestock pedigrees? Why
not?
TG
_________________
Terry M. Gray, Ph.D., Computer Support Scientist
Chemistry Department, Colorado State University
Fort Collins, Colorado 80523
grayt@lamar.colostate.edu http://www.chm.colostate.edu/~grayt/
phone: 970-491-7003 fax: 970-491-1801
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