Freethought & Rationalism Archive

Sauron · 03-05-2002, 11:55 AM

In this article:
<a href="http://www.reasons.org/resources/apologetics/chromosome.html" target="_blank">http://www.reasons.org/resources/apologetics/chromosome.html</a>

Ross states:

Quote:

To their great surprise, Dorit and his associates found no nucleotide differences at all in the non-recombinant part of the Y chromosomes of the 38 men. This non-variation suggests no evolution has occurred in male ancestry. The researchers, apparently committed to Darwinism, back-pedaled by doing statistical analysis on the evolutionary possibilities if the 38 men sampled somehow inaccurately represented the population at large. Based on this analysis, they concluded that men�s forefather � a single individual, not a group � lived no more than 270,00 years ago.

Lord Valentine said:

Quote:

I looked at there reference and the title of the cited article gives away the nonsense. They did not check ALL of the non-recombinant
parts of the Y-chromosome, but looked at a single locus. The abstract from PubMed is online here.
729 base pairs do not a chromosome make!

I am assuming that Ross' conclusion (i.e., that no evidence for human evolution existed) is invalid here, because a person cannot make that claim by examining only one section of the non-recombinant part.

I.e., that the locus examined (729 base pairs) doesn't include all the non-recombinant parts of the y-chromosome.

Is this correct?

Thanks.

Boshko · 03-05-2002, 12:41 PM

Well there have probably been bottlenecks in the human population that reduced the human population to relatively few males which accounts for y-cromosone similarity.

tronvillain · 03-05-2002, 03:49 PM

You don't need to resort to that to explain Y-Chromosome Adam any more than you do to explain Mitochondrial Eve. Given a certain y-chromosome extinction rate (not every male has a son) eventually there will be one male who is the most recent common ancestor of everyone alive with respect to patrilineal descent, but that doesn't mean there weren't many other males around at the time.

Gringo · 06-08-2002, 10:22 PM

What has me wondering though is that <a href="http://www.cosmiverse.com/science111503.html" target="_blank">Y Chromosome Adam</a> was supposedly dated to 59,000 years ago, yet Australian ancestors migrated out of Africa 60,000 years ago. Though I know there is a margin of error greater than a 1000 years, how can it be that these migrations are so close to the age of Y Chromosome Adam. Modern man was all over the place 50,000 years ago (and many such as the Australian aborgines have been largely isolated since that time), so how could Y Chromosome Adam be so recent?

[Edited to fix link -sci]

[ June 09, 2002: Message edited by: scigirl ]

scigirl · 06-09-2002, 08:49 AM

Quote:

Based on this analysis, they concluded that men�s forefather � a single individual, not a group � lived no more than 270,00 years ago.

What number is this supposed to be? 270? or 270,000?

scigirl

Liquidrage · 06-09-2002, 09:03 AM

Quote:

Originally posted by Gringo:
What has me wondering though is that <a href="http://www.cosmiverse.com/science111503.html" target="_blank">Y Chromosome Adam</a> was supposedly dated to 59,000 years ago, yet Australian ancestors migrated out of Africa 60,000 years ago. Though I know there is a margin of error greater than a 1000 years, how can it be that these migrations are so close to the age of Y Chromosome Adam. Modern man was all over the place 50,000 years ago (and many such as the Australian aborgines have been largely isolated since that time), so how could Y Chromosome Adam be so recent?

[Edited to fix link -sci]

[ June 09, 2002: Message edited by: scigirl ]

A second migration who genes eventually superceed those of the inital migration would be a possibility.

Dr.GH · 06-09-2002, 10:39 AM

I think you're getting hung up on the "Adam" idea. Instead of thinking that the DNAdam was the first human male, bare in mind that this is just the estimated time since the most recent common male ancestor of current humans. As tronvillain points out, there were earlier humans.

Bill · 06-09-2002, 06:05 PM

The theory of "genetic bottleneck" has been given air time on the BBC in conjunction with the eruption of a super-volcano in Sumatry about 74,000 years ago. The script for the BBC video piece is <a href="http://www.bbc.co.uk/science/horizon/supervolcanoes_script.shtml" target="_blank">HERE</a>.

Frankly, I would personally presume that the inaccuracies in the measurement of the length of time to the "genetic Adam" could easily be off enough to account for the difference between 59,000 years (their estimate) and the time of the "bottleneck," about 74,000 years ago. It is only 15,000 years out of 74,000 years.....

== Bill

KeithHarwood · 06-10-2002, 05:53 PM

Quote:

Originally posted by Gringo:
What has me wondering though is that <a href="http://www.cosmiverse.com/science111503.html" target="_blank">Y Chromosome Adam</a> was supposedly dated to 59,000 years ago, yet Australian ancestors migrated out of Africa 60,000 years ago.

Last I heard this was very controversial. I think only Alan Thorne supports this date. Most archaeologists seem to put aborigines in Oz 32-38,000 BC. A popular song supports the 38,000 BC.

06-08-2002, 10:22 PM	#4
Gringo Regular Member Join Date: Sep 2001 Location: WV Posts: 207	What has me wondering though is that <a href="http://www.cosmiverse.com/science111503.html" target="_blank">Y Chromosome Adam</a> was supposedly dated to 59,000 years ago, yet Australian ancestors migrated out of Africa 60,000 years ago. Though I know there is a margin of error greater than a 1000 years, how can it be that these migrations are so close to the age of Y Chromosome Adam. Modern man was all over the place 50,000 years ago (and many such as the Australian aborgines have been largely isolated since that time), so how could Y Chromosome Adam be so recent? [Edited to fix link -sci] [ June 09, 2002: Message edited by: scigirl ]</p>

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search

03-05-2002, 12:41 PM	#2
Boshko Regular Member Join Date: Jun 2001 Location: Wesleyan University Posts: 361	Well there have probably been bottlenecks in the human population that reduced the human population to relatively few males which accounts for y-cromosone similarity.

03-05-2002, 03:49 PM	#3
tronvillain Veteran Member Join Date: Oct 2000 Location: Alberta, Canada Posts: 5,658	You don't need to resort to that to explain Y-Chromosome Adam any more than you do to explain Mitochondrial Eve. Given a certain y-chromosome extinction rate (not every male has a son) eventually there will be one male who is the most recent common ancestor of everyone alive with respect to patrilineal descent, but that doesn't mean there weren't many other males around at the time.

06-09-2002, 10:39 AM	#7
Dr.GH Veteran Member Join Date: Jul 2001 Location: Dana Point, Ca, USA Posts: 2,115	I think you're getting hung up on the "Adam" idea. Instead of thinking that the DNAdam was the first human male, bare in mind that this is just the estimated time since the most recent common male ancestor of current humans. As tronvillain points out, there were earlier humans.

06-09-2002, 06:05 PM	#8
Bill Veteran Member Join Date: Dec 2002 Location: Gatorville, Florida Posts: 4,334	The theory of "genetic bottleneck" has been given air time on the BBC in conjunction with the eruption of a super-volcano in Sumatry about 74,000 years ago. The script for the BBC video piece is <a href="http://www.bbc.co.uk/science/horizon/supervolcanoes_script.shtml" target="_blank">HERE</a>. Frankly, I would personally presume that the inaccuracies in the measurement of the length of time to the "genetic Adam" could easily be off enough to account for the difference between 59,000 years (their estimate) and the time of the "bottleneck," about 74,000 years ago. It is only 15,000 years out of 74,000 years..... == Bill

Freethought & Rationalism Archive

The archives are read only.