Mitochondrial DNA, not a ‘neutral marker’ but DNA under selection
I had a bit of a brainwave last night…
It went something like….We share 60% of our DNA with a banana. This is here for perspective.We share 96% of our DNA with Chimps.
We share 98.4% or our DNA with Bonobos.
Therefore, only 1.6% of our DNA is human species specific.
Individually, we are 99.3% the same (an average). Used to 99.9%, but the man who came up with the figure corrected it (Venter).
Of these differences, 85% are within populations, and 15% between populations (races).
So, of the 0. 7% about 0.1% is racial variation.
This makes just over 6% of our human only DNA to be what separates us into racial sets.
It doesn’t sound so little now, does it.
Although, this is probably a little out, as they keep wiggling the percentages. You get the idea though.
Also, a quote from a study involving a computer and genetics.
The scientists studied 377 microsatellite sequences from 1056 individuals from 52 populations worldwide. They fed the data to a computer programme called structure which takes any set of data and attempts to find a rational way of dividing it into as many groups as it is asked to. The number of groups into which the data set is broken down is denoted by the letter K.In this study, structure was asked to divide up the populations of the world (represented by the 52 DNA samples) into two, three, four and five groups according to how similar or dissimilar were their DNA sequences. When the scientists set asked the programme to divide the population of the world into two groups, one group comprised of Africa, Europe and western Asia and the second group of eastern Asia, Australia and the Americas. When K=3, the group consisting of populations from Eastern Asia and the Americas remained unchanged. But the populations of sub-Saharan Africa were separated from those of Europe and Western Asia. In other words, the three groups were the populations of sub-Saharan Africa, those of Europe and Western Asia, and those of Eastern Asia, Australia and the Americas. When asked to create four groups, structure created a new group by separating the populations of eastern Asia and the Americas. And when asked to break the data into five groups, structure kept all the other groups as they were but separated off the populations of Australia from the rest of Asia.There are two things remarkable about these findings. First, the computer programme divides the population of the world according to the continent on which they live, and as we move from K=2 to K=5 the boundaries of the continents become ever more distinct. Second, when the world’s populations are divided into five groups, those five groups correlate closely with what we call ‘races’: Africans, Caucasians, Orientals, Australasians and Native Americans. And all this from DNA sequences in which only 4 per cent of total human variation is apportioned out among the races. Rosenberg’s study seems to suggest that, however small the differences between races, they are nevertheless sufficient to pick them out.