A team consisting of people from the University of Tübingen, the Max Planck Institute for the Science of Human History, the University of Cambridge, the Museum and Institute of Zoology (Polish Academy of Sciences), the Berlin Society of Anthropology, Ethnology and Prehistory and the University of Adelaide has recently published a very interesting genetic study of ancient Egyptian mummies in Nature.
According to the authors, previous studies suffered from possible contamination due to the type of method used: direct PCR and it was generally believed that the climate and mode of mummification destroyed any chance of finding good human DNA.
The authors studied 150 mummified individuals using a high-throughput DNA sequencing method and selecting 90 individuals for further study. The samples obtained span around 1,300 years of Ancient Egypt, namely the Pre-Ptolemaic (New Kingdom, Third Intermediate Period and Late Period), Ptolemaic and Roman periods.
The authors’ conclusion was:
We find that all three ancient Egyptian groups cluster together, supporting genetic continuity across our 1,300-year transect. Both analyses reveal higher affinities with modern populations from the Near East and the Levant compared to modern Egyptians.
One interesting note is: While this result by itself does not exclude the possibility of much older and continuous gene flow from African sources, the substantially lower African component in our ∼2,000-year-old ancient samples suggests that African gene flow in modern Egyptians occurred indeed predominantly within the last 2,000 years.
Basically, if the population studied is representative of the all of the people in Ancient Egypt, the conclusion is that they were not Africans and that modern Egyptians share more genes with African populations than their ancestors.
(Score: 0, Offtopic) by khallow on Saturday July 01 2017, @07:30PM
To answer your question, racism divisions don't have to be the best way, they merely needs to be effective enough to distinguish ethnicity or culture. Now, let's consider your middle portion:
My view is that there probably has been heavy selection for people who look a certain way, say the local standard of beauty for that culture. But genes affect a lot more than just exterior appearance. We wouldn't expect genes for internal body organs or the immune system to be similarly affected by bias towards certain appearances. This will result in heavy selection for genes that affect exterior appearance while only affecting indirectly genes that don't (for example, if the gene happens to be riding on a chromosome with appearance relevant genes, or is dependent on a common protein).
So you can end up with the situation that sure, there is more intrarace genetic diversity, but that diversity goes way down once it gets to appearance-affecting gene combinations. It's not just skin, eye, and hair genes. Genes also have subtle effects on height, build, and other exterior morphological characteristics (even if we looked at photos that are altered to be, say gray-scale with all skin, eye, and hair tones the same color, we'd still be able to strongly guess at the heritage of the person. I suspect in some cases to find out that it has an effect on personality and intellect as well.
Something is going on here because we do see cultures of people with inheritable common appearance and physical characteristics. And these cultures tend to be surprisingly durable.
Or echoing the same verbal short cut that the researchers made. For what it's worth, my assumptions of what "Africa" meant were accurate, but it's reasonable to expect that not everyone reading the SN summary would understand the distinctions made.