My wife's a primate, and so are you

blog.nj.com ^ | February 26, 2009 | Paul Mulshine

[allmendream]

Yes, usually nonfunctional DNA is used to reconstruct phylogenetic relationships as it usually changes at the neutral mutation rate.

Similarity between species when comparing DNA goes by category of similarity.

Genes are the most similar, they have functional constraints, a hemoglobin gene cannot make a protein that doesn't bind oxygen and remain functional.

Proteins are even more similar because the DNA code is redundant, many of the differences between species in genes are “silent” mutations because they don't actually change what amino acid is being coded for.

Regulatory sequences can also show high evolutionary conservation between species.

That is why usually endogenous retroviral sequences are used, or pseudogenes, or long repeat sequences. They are more different than genes in the same comparison.

For example humans and chimps are about 98% similar in their genetic DNA, but only 94% similar over the entire genome.

That difference is magnified when comparing a more distantly related species like a mouse or rat.

The genetic DNA would be about 85% similar, but the genomic comparison would show a much greater divergence.

[reg45]

Since humans share 95% of their DNA with monkeys, if someone calls you a monkey, they are 95% correct.

[reg45]

A little music from J. Fred Obama.