Chromosome Changes in Evolution
Location: Outside U.S.
Date: October 2008
Regarding human evolution: A chromosomal fusion event occured
in our (human) evolutionary history that brought our number down to 23
pairs (vs 24 in other apes). How would this type of mutation (I believe
its termed a Robertsonian translocation) get passed on?
I don't believe it is an example of Robertsonian translocation because that is
when two acrocentric chromosomes break apart at the centromeres and two of the
nonhomologous arms fuse together. My understanding of the fusion that occurred
in primates to make the human diploid number was when two whole chromosomes
fused. The p arms of both are fused. The evidence for this is that there is
telomeric DNA internally, as if the ends of two chromsomes fused at their
tips. There are also two centromeres, although one of them has accumulated
enough mutations that it doesn't serve as a second centromere any more.
You can read more at:
I must be missing something here. A fused chromosome would get passed on the
same way any other chromosome that confers a selective advantage on the
Ron Baker, Ph.D.
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Update: June 2012