Hominid Inbreeding And The Bottleneck

From: Rich Travsky (traRvEsky_at_hotmMOVEail.com)
Date: 01/26/05 

Date: Wed, 26 Jan 2005 09:16:53 -0700

 http://www.newscientist.com/article.ns?id=dn6920

 A lack of mates among human ancestors that lived million years ago
 has left modern humans more vulnerable to genetic disease, a new
 study suggests.

 Researchers compared samples from the genomes of more than 1000
 people with those of chimpanzees to see how much genetic mutation
 has occurred in the two species since they diverged from a common
 hominid ancestor, about six million years ago. They also made
 comparisons with another closely related pair of species, rats and
 mice.

 They focused on portions of DNA close to protein-coding genes.
 These segments are thought to regulate the activation of these
 genes.

 The researchers calculated that these stretches of human and chimp
 DNA contained approximately 140,000 non-advantageous mutations,
 higher than expected and well above the number of retained genetic
 mutations seen in rats and mice. The mutations occur naturally but
 make both chimps and humans more susceptible to diseases with a
 genetic basis, such as cancer.

 The researchers believe the high rate of mutations is seen because
 the hominid ancestor to both species went through an evolutionary
 bottleneck, when its breeding population was limited to only about
 10,000 individuals.

 This meant that the process of pruning out damaging mutations via
 natural selection of the fittest mates was more difficult and slower.
 In contrast, rats and mice have descended from a much larger
 population, leaving them less susceptible to genetic diseases.
 ...

Relevant Pages

  • Re: Article: Hominid inbreeding left humans vulnerable to disease
    ... > hominid ancestor, ... > than expected and well above the number of retained genetic mutations ... > bottleneck, when its breeding population was limited to only about ... > natural selection of the fittest mates was more difficult and slower. ...
    (sci.bio.evolution)
  • Re: Challenge for Darwinists - Protein Synthesis
    ... mutations per diploid genome between each generation. ... ultimately 'coalesce' on a common ancestor. ... would all have the same sequence as that ancestor (this is even more ... all variation in an initially varying population will be ...
    (talk.origins)
  • Re: For Glenn
    ... >>>The mutations that cause genetic disease don't travel to fixation, ... >>>the great bulk of mutations do. ... >>The great bulk of neutral mutations are lost fairly quickly. ...
    (talk.origins)