Interspecies and Intraspecies Differences
Country: United States
Date: October 2007
If chimpansees and humans share more then 95% or their genes,
what percentage of their genes do random humans share with each other?
If that should be close to 100%, what meaning does the concept of family
relatedness still have? What am I missing here?
If unrelated humans have 99.9% of their gene sequences in common, it follows
that 0.1% are different. Given that the human diploid genome consists of
approximately 6 billion base pairs worth of DNA, this means that on average,
two people differ by 0.1 % x 6,000,000,000 = 6,000,000 base pairs. That is
alot of variation!
Ron Baker, Ph.D
The number varies depending on what source you refer to, but humans and
chimpanzees seem to share around 98.5% of their genes. Any two humans are
about 99.9% the same, so on average they differ by 0.1%. The human genome
has 3.5 BILLION "letters". So 0.1% is 3 MILLION letters. There is still a
lot of room for difference. But we are finding that we share 80% of our
genes with mice. There are certain genes that all living things share
just because they are alive. It is becoming clear that it is not so much
how many letters we share, but how those letters are used; in other words
it is how the genes are regulated that seems to matter the most.
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Update: June 2012