I have been researching the purported genetic near-identity between humans and chimps-- asserted as the "scientific" basis for the Great Ape Project
--and found (unsurprisingly) that the entire advocacy line that "humans and chimps share 98% of our genes" is plain false. This gets a little complicated, so stick with me.
First, the 98% figure is probably overstated. An article in Science
puts the actual figure at 94%. (Jon Cohen, "Relative Differences: The Myth of 1%, June 29, 2007). But even these figures are only measuring about 2% of our total genetic makeup
--that is, those genes that code for proteins, the building blocks of our physical bodies and functions.
The vast majority of our DNA, known as "non-coding DNA"--sometimes called "junk DNA" because it was once thought not to have function--is very different in humans from most non coding genes found in chimps and other apes. Moreover, recent research has found that contrary to previous belief, this repetitive DNA isn't "junk" after all, but has distinct purposes. Research continues as to the exact nature and functions of non coding genes, but given the wide differences between human and ape non coding DNA--even if the purported 98% genetic similarity to coding DNA is true, it is actually only 98% of a much smaller percentage of our total genetic makeup,
perhaps as low as 98% of 2%!
Proponents of the Great Ape Project might reply in defense that the coding genes are the ones that really count, but that is not scientifically supported anymore. And even if true, as we have discussed previously here at SHS
, the 2-6% difference constitutes tens of millions of biological differences.
So this is the bottom line: Creating a human/chimp moral equivalency is not scientifically justified based on a close biological relationship between us that is actually quite vast. Rather, as one scientist quoted in the Science
article referenced above put it about this issue:
I don't think there is any way to calculate a number [percentage of similarity]. In the end, it's a political and social and cultural thing about how we see our differences.
Exactly: This is about politics and ideology, pure and simple.
I'll write more fully on this matter when I have a little more time because I think it is important to knock down the fiction that humans and chimps are nearly identical genetically. But know this: We are not 98% (or 94%) chimp and they are not 98% (or 94%) human. And that's the scientific truth.