(June 24, 2018 at 7:41 am)paulpablo Wrote: In other words neither is a deficiency, they've both been selected for in evolution.
The are deficiencies in the area where they are de-selected for.
They were probably not lethal deficiciencies, which is why Europeans can still go back to living in subsahara Africa before the invention of sun screens, and evidence suggest Homo sapiens populations in Northern Europe and Asia remained predominantly dark skinned for a long time after first getting there. But they were a deficiency. Which is why over thousand sod time, the frequency of these genes responded in the expected way.
