[Taxacom] Schwartz and Grehan (2009) cited on Dinosaur Mailing List

John Grehan jgrehan at sciencebuff.org
Thu Sep 15 11:31:56 CDT 2011


I don't have any answers, although they are the sort of questions that
perhaps should be explored. The way I look at biology, we inherit
developmental systems and in this respect I do not decouple molecular
genetics from developmental genetics. But the current molecular DNA
approach effectively decouples the molecules from the developmental
systems that represent the evolutionary meaning of those bases.

 

John Grehan

 

________________________________

From: Robinwbruce at aol.com [mailto:Robinwbruce at aol.com] 
Sent: Wednesday, September 14, 2011 7:18 AM
To: John Grehan
Cc: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Schwartz and Grehan (2009) cited on Dinosaur
Mailing List

 

John,

 

Despite the risk of clouding already muddy waters, I thought I would
throw in my 2 cents worth.

 

Indeed, how equivalent are genetic information systems, and
morphogenetic/epigenetic order systems? Are they sufficiently similar in
their natures to make comparisons between them useful or instructive?
The former seem to be largely decoupled from organismic time/space, and
represent a linear informational continuity of life (pre formation, dare
one say?); the latter are intrinsic (immanent?) to the time/space
germination of biological order (epigenesis, dare one say?). Information
v. process?

 

Perhaps the former resolve by a calculus of classes; the latter, by a
calculus of individuals; and perhaps there can be no ready equivalence
between them.

 

Robin

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In a message dated 9/13/2011 3:30:53 P.M. GMT Daylight Time,
jgrehan at sciencebuff.org writes:

	The problem with the various molecular patterns being congruent
is that
	the congruence may not necessarily lend any greater weight if
they are
	based on the same kinds of assumptions. As for morphology
(really
	morphogenetics) it is not a 'single' source, but multiple
developmental
	genetic systems.
	
	With respect to the Yunis and Prakash paper, Schwartz (1987)
noted the
	following:
	
	Humans and orangutan have in common chromosome 5, a particular
pattern
	of 12 and 19, and most of Yq, the lower extent of the Y (male
sex)
	chromosome. 
	
	The chimpanzee and the gorilla also share four apparently
homologous
	chromosomes - another configuration of 12, 19, 20, and 21 - but
with
	different banding patterns from those which distinguish
chromosomes 12
	and 19 in humans and orangutans.
	
	Without at least the gibbon for comparison, one cannot begin to
get any
	insight into which banding pattern on any given chromosome is
derived
	for the hominoids. But we are left with the tantalizing hint of
support
	for the unity of humans and orangutans as well as for
chimpanzees and
	gorilla
	
	John Grehan
	
	-----Original Message-----
	From: Kim van der Linde [mailto:kim at kimvdlinde.com] 
	Sent: Tuesday, September 13, 2011 10:06 AM
	To: John Grehan
	Cc: taxacom at mailman.nhm.ku.edu
	Subject: Re: [Taxacom] Schwartz and Grehan (2009) cited on
Dinosaur
	Mailing List
	
	John,
	
	I have been working on drosophilid phylogenies for a while, and
I have 
	seen the whole range of sources that have been used. When I see
plain 
	basepair phylogeny be congruent with chromosome banding
phylogenies, 
	being congruent with isozyme based phylogenies being congruent
with 
	indel patterns being congruent with gene duplication patterns
being 
	congruent with internal morphology, I am convinced that the
mismatches 
	in the external morphology are not going to be better than the
rest. I 
	see a similar pattern with the great ape discussion. The DNA
phylogeny 
	is congruent with chromosome banding patterns for example. If
you want 
	to show that several sources of information are all incorrect
and the 
	morphological evidence is superior, you have to show how those 
	similarities arose to the point that they are misleading for the
actual 
	family history. Yes, when you have multiple sources claiming one
thing 
	and one source the opposite, it becomes an extraordinary claim
requires 
	extraordinary evidence situation.
	
	Just one example: Yunis, J. J., Prakash, O., The origin of man:
a 
	chromosomal pictorial legacy. Science, Vol 215, 19 March 1982,
pp. 1525 
	- 1530
	
	Kim
	
	
	On 9/13/2011 9:49 AM, John Grehan wrote:
	> It's a bit meaningless to say that "extraordinary claims
require
	> extraordinary evidence". What is the extraordinary claim here?
Is it
	any
	> less extraordinary to assert that base sequences provide the
answer
	than
	> anything else?
	>
	> As for the chromosomal rearrangement patterns, what sources
are your
	> referring to and what evidence specifically?
	>
	> John Grehan
	>
	> -----Original Message-----
	> From: taxacom-bounces at mailman.nhm.ku.edu
	> [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kim
van der
	> Linde
	> Sent: Tuesday, September 13, 2011 9:41 AM
	> To: taxacom at mailman.nhm.ku.edu
	> Subject: Re: [Taxacom] Schwartz and Grehan (2009) cited on
Dinosaur
	> Mailing List
	>
	> Well, I always liked the chromosomal rearrangement patterns
the best
	as
	> evidence for human-chimp, especially chromosome two that is
most
	similar
	>
	> to the chimpanzee chromosomes. Really, parallelisms are so
common that
	> you need far more than some morphological similarities to be
able to
	> reject the results of many thousands of base-pairs, in-dels,
	chromosome
	> inversions etc. Extraordinary claims require extraordinary
evidence.
	>
	> Kim
	>
	> On 9/12/2011 11:26 PM, Kenneth Kinman wrote:
	>> Dear All,
	>>          I was catching up on postings at the DML (Dinosaur
Mailing
	> List),
	>> and one last week caught my eye.  It cites the paper by
Schwartz and
	>> Grehan (2009) challenging the exclusivity of a supposed
chimp-hominid
	>> clade.  Although the poster has reservations about the
paper's
	>> conclusions, he does make some interesting observations (as
does Greg
	>> Paul, whose posting he is responding to).  However, one thing
that he
	>> fails to point out is that Schwartz and Grehan, 2009, do not
produce
	>> even a single molecular character to support their proposed
	>> orangutan-hominid clade, which in my mind is it biggest
shortcoming.
	>>          Therefore, if Schwartz and Grehan cannot produce any
	molecular
	>> evidence to support an orangutan-hominid clade, and the
molecularists
	>> cannot produce convincing morphological evidence for a
chimp-hominid
	>> clade, then I still feel that hominids most like did not
exclusively
	>> clade with either of them, but that they are sister group to
a
	>> chimp-gorilla clade.
	>>          It seems that symplesiomorphies are relatively easy
to find
	> among
	>> greats apes, but finding true synapomorphies (molecular or
	>> morphological) for its subclades is no easy matter.  I have
little
	> hope
	>> of relevant fossil finds shedding much light on the debate
anytime
	> soon,
	>> but whole genomes (especially certain LINES contained
therein) will
	> soon
	>> make considerable progress in resolving this debate.  Anyway,
for the
	>> DML postings (for what they are worth), see the weblink
below.
	>>             -----------Ken Kinman
	>>
	>> http://dml.cmnh.org/2011Sep/msg00030.html
	>>
	>>
	>>
	>> _______________________________________________
	>>
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	>
	
	-- 
	http://www.kimvdlinde.com
	
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