FW: Haldane

Tue, 29 Aug 95 10:45:00 CDT

A follow up post... -JDF-
From: jpt
To: CRSnet (Creation Reflector)
Subject: Re: Haldane
Date: Tuesday, August 29, 1995 10:59PM

Todd Wood said:
> John P. Turnbull asked about intrabaraminic genetic variation and
> whether this falls prey to the Haldane dilemma. While I am not
> well-acquainted with the Haldane dilemma (a short tutorial would
> be nice), I can say that most genetic sequence variation is not
> baraminologically informative. I have appended to my message an
> alignment of mammalian myoglobin sequences. The sequences come
> from a possum (D_virg), a platypus (O_anat), a cow (B_taur), and
> a whale (E_gibb). The sequences were aligned using Felsenstein's
> pileup program in his PHYLIP package. You can see quite plainly
> that even over this diverse selection of mammals that the myoglobin
> sequences are extremely similar. This is the rule rather than
> the exception. What baraminologists should be interested in are
> what I call baraminic markers (molecular synapomorphies), specific
> genetic characteristics that are unique to a particular baramin.


There is a brief tutorial on Haldane's dilemma in Drury Woodson's
recent post titled _Re: Evolution and beneficial mutations_.

Haldane puts forth an arguement that estimates the upper bound for
the greatest possible divergence in the molecular DNA sequence and
applies his analysis to show that a supposed pre-human ancestor
could not have produced more than 500,000 beneficial mutations in
about 10 million years time which is about 0.014% change. That's
far too small to account for the 2 - 3% differences between chimps
and humans. His methods may or may not be bogus, but the question
I was asking is if we apply the same analysis to the variations that
originated from some original kind, do we find that differences between
variations exceed this theoretical limit. To do this, we would need to
apply his method to estimate an upper limit we can expect for a basic kind
like a dog, for example, to change over 10,000 years or so and then check
to see if all variations of the dog kind are within this limit.



John P. Turnbull (jpt@ccfadm.eeg.ccf.org)
Cleveland Clinic Foundation
Dept. of Neurology, Section of Neurological Computing
9500 Euclid Ave.
Cleveland Ohio 44195
Telephone (216) 444-8041; FAX (216) 444-9401