Nature September 1 issue

John Grehan jgrehan at SCIENCEBUFF.ORG
Fri Sep 9 15:56:52 CDT 2005


Thank you for attempting a philosophical solution. I would agree that
taking the 'total evidence' into consideration is worth pursing IF all
the evidence was of equal value and directly comparative. In the case of
the orangutan, when one takes the total evidence into account it is a
case where patterns of DNA sequence similarities do not match the
preponderance of uniquely shared morphological characters. If one takes
the view (as I would) that DNA sequence analysis and morphological
analysis are each independent research programs, simply combining the
data would only provide the illusion of a solution. In the case of DNA
sequence similarities there are good reasons to understand the sequence
similarity of humans and chimpanzees as phylogenetically misleading
because of the inability of the current sequence methodology to weed out
similarities through shared primitive states. Even using outgroups to
polarize the similarities to build a tree does not solve this problem. 

Perhaps to oversimplify, if I were to take 'total evidence' into account
I would say the world is flat, but I have chosen to selectively accept
that part of the total evidence that defies common sense experience -
that the world is round. In the orangutan case it is my opinion
(obviously not shared by the majority) that the notion that we share
virtually everything uniquely in common with orangutans and have hominid
ancestors that do the same thing through a 'mistake' (homoplasy or
whatever) is more absurd than the possibility that shared primitive
sequences result in a closer sequence similarity with chimpanzees than
our real closest relatives. 

The real problem for science is not the conflict, but the suppression of
exploration of the conflict by editors of scientific journals. Perhaps
it would be too embarrassing to admit that millions of $ may have been
spent on sequencing the chimpanzee for the wrong reason, or that it
might be less informative than a far less expensive morphological
research program (which NSF and other would of course not fund).

John Grehan

> -----Original Message-----
> From: Taxacom Discussion List [mailto:TAXACOM at LISTSERV.NHM.KU.EDU] On
> Behalf Of J. Kirk Fitzhugh
> Sent: Friday, September 09, 2005 2:30 PM
> Subject: Re: [TAXACOM] Nature September 1 issue
> At 08:34 AM 9/9/2005 -0400, John Grehan wrote:
> >A solution to the conflicting evidence [regarding relations among
> >orangutans, chimps, humans] has yet to be resolved. Simply ignoring
> >problem is not good science.
> John,
> The solution for conflicting evidence has been around for a long time.
> It's
> called the requirement of total evidence.  Carl Hempel (2001: 114,
> Science,
> Explanation, and Rationality) provided a particularly lucid
description of
> the solution you seek.  One might then conclude that rationality is
not a
> concern of the editors of Nature:
> 'The general consideration underlying the requirement of total
evidence is
> obviously this: If an investigator wishes to decide what credence to
> to an empirical hypothesis or to what extent to rely on it in planning
> actions, then rationality demands that he take into account all the
> relevant evidence available to him; if he were to consider only part
> that evidence, he might arrive at a much more favorable, or a much
> favorable, appraisal, but it would surely not be rational for him to
> his decision on evidence he knew to be selectively biased.  In terms
> the
> concept of degree of confirmation, the point might be stated by saying
> that
> the degree of confirmation assigned to a hypothesis by the principles
> inductive logic will represent the rational credibility of the
> for a given investigator only if the argument takes into account all
> relevant evidence available to the investigator' (Hempel 1962, 2001:
> Sincerely,
> Kirk Fitzhugh
> -----------------------------------------------------
> J. Kirk Fitzhugh, Ph.D.
> Curator of Polychaetes
> Invertebrate Zoology Section
> Research & Collections Branch
> Los Angeles County Museum of Natural History
> 900 Exposition Blvd
> Los Angeles CA 90007
> Phone:   213-763-3233
> FAX:     213-746-2999
> e-mail:  kfitzhug at
> ----------------------------------------------------

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