Extra DNA in Humans
Country: United States
Date: October 2008
Why do humans have extra DNA?
One explanation is that we simply don't know its function yet (but that
doesn't mean it doesn't have a function). Another is that a mutation or
other change has rendered a sequence non-functional, but the remaining
sequence remains in our genome.
Hope this helps,
All eukaryotes have extra DNA. One theory is that it provides for the evolution
of new genes which, of course, is the raw material for future evolution.
Ron Baker, Ph.D.
I'm not sure I fully understand what you are asking. However, here are
to items that may address your inquiry. First, some DNA (and other
substances, cells, and even organs) contain redundant, i.e. backups in
case something fails. Two examples and the kidney and liver. If those
organs, and hence their cells right down to their DNA, stop
functioning they can continue to function. Second, only a fraction of
the functions and use of DNA is known. The use of major amounts of the
DNA remains unknown. This has been called "junk" DNA. But that is not
a good name. It's not "junk" we just don't yet know what its function
There is one idea about this topic that suggests that this DNA may be
left over as a result of evolutionary processes. Advanced
organisms may have left over DNA from their ancestry prior to being
our current stage of "Homo sapiens", for example. Humans have a great deal of
identical or similar genes to fish, reptiles, etc., but, of course,
we have evoled to a different stage of development. We just have
previously used.but now junk DNA in our genome, much like left over crumbs.
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Update: June 2012