I am totally not a math person and so even more totally not a statistics person. I try, I really do, because I think math is really important to understand, especially in science (and it’s why physics often leaves me in the dust). I taught biology (yes, I understand the problem with that).
My Dad and 2 of my sons are mathy, so I generally ask them to explain it to me. Anyway, I have been (slowly) reading thru an interesting article in a magazine I get called Science News (an interesting altho sometimes annoying little mag that believes heart and soul in mad made global warming and other liberal causes) that I have subscribed to for years because it has all the most up to date science news generally in short articles.
This particular article talks about the shortcomings of statistics in sciences, and while it’s tough reading for someone like me who is not a statistics person, I was thrilled to see that someone is addressing the subject. If you are interested, it is online here.
http://www.sciencenews.org/view/feature/id/57091/title/Odds_Are,_Its_Wrong
A little off topic, but still, perhaps interesting to you.
I'm talking here about real basic math and statistics -- you got a numerator, you got a denominator, you do the division and come up with a percentage. If I understand the first two, then I know what the last one means.
In this particular case, I do understand that 3 million base-pair differences amongst humans and Neanderthals is one-tenth of one percent of the 3 billion total.
What I don't understand is how we go from that to saying 1% or 4% of human DNA came from Neanderthals.
This is not complex math, it just in how we define our terms.