Sigh.
This is bunk science.
Say you look at samples and find that the overall variation is 3 percent.
Then you look at the mean of neanderthals vs the mean of humans and find that it’s 3 percent.
It doesn’t mean ‘neanderthals fall within normal human variation’. You would have to use standard deviations.
Bump for later when some scientific types post something enlightening.
Sounds to me like real serious science going on -- human and Neandertal DNA analysis is about as high-tech as anyone can get -- but those statistics they throw out seem, well, questionable.
"The results from the new studies confirm the Neanderthal's humanity, and show that their genomes and ours are more than 99.5 percent identical, differing by only about 3 million bases."This is a drop in the bucket if you consider that the human genome is 3 billion bases," said Edward Rubin of the Lawrence Berkeley National Laboratory, who led one of the research teams.
"For comparison, the genomes of chimpanzees, our closest living relatives, differ from humans by about 30 million to 50 million base pairs."
Think about those numbers:
3 million different base pairs out of 3 billion total is one-tenth of one percent, which would make human & Neanderthal DNA 99.9% the same.
But they report it as "99.5%".
What is that, a rounding error?
Also note that humans and chimps differ by 30 million to 50 million base pairs. Well, that would be 1% to 1.7%.
But the usual statistics say human & chimp DNA is only 95% the same.
No doubt it all depends on exactly how you count these things.
Here's my point: if human and Neanderthal DNA is 99.9% identical -- only 3 million out of 3 billion base pair differences -- then how can anyone say that one or two or four percent of human DNA comes from Neanderthals?
I'd say it doesn't all add up, and someone probably needs to go back and refigure it.