RE: primate interrelatedness

Sweitzer, Dennis (
Tue, 21 May 96 18:25:00 EST

Gladwin asked about human and ape DNA.

Jim replied (with an excellent explaination)
>>>>>The statement about 99% of the DNA being similar is approximately
While having the complete gene sequences will be helpful, the data from
DNA-DNA hybridization experiments is easier to obtain and is probably just
as accurate.

How does this fit in with genetic matching ala gel electrophoserisis (excuse
my spelin)? [This is where special enzymes are used to cut the DNA where
certain DNA sequences are found. The result is a mix of various sized DNA
fragments, which can be sorted by size using an electric field, yielding
striped band. The width and location of stripes correspond to specific DNA
fragments; since genomes vary between individuals, any two (non-twin)
individuals will have a different sequence of stripes. This is the type of
DNA comparison used in legal trials, e.g., O.J. Simpson].

I always assumed the 99% figure was based on this technique--has this
technique been used?

Also, how much does DNA vary between any two individuals? What kind of
results does the hybrid DNA test yield for any two human individuals?

Could it be possible that two humans be at 98% similarity, while a human and
ape be at 99%? For instance, if one human shares a similar blood type Rh
factor, hair color, eye color, etc with the ape, but opposite
characteristics to the other human?

Is it conceivable that humans and apes have 99% of the same alleles coding
for various traits (on a population level), the remaining 1% providing the
critical distinction? [An allele is gene variation--such as one for blue
eyes, one for brown eyes]. But while a population may have a large variety
of alleles, any individual may only have a couple alleles, consequently if a
pair of people vary on enough of the specific genes, one (or both) may
appear closer related to apes (especially if selected to match on alleles)?

Just curious (I'm obviously no expert on this topic),

Dennis Sweitzer