PMC:5985360 / 29458-30487 JSONTXT

{"project":"2_test","denotations":[{"id":"29526279-26108492-2046662","span":{"begin":190,"end":192},"obj":"26108492"},{"id":"29526279-27654912-2046663","span":{"begin":226,"end":228},"obj":"27654912"},{"id":"29526279-26108492-2046664","span":{"begin":375,"end":377},"obj":"26108492"},{"id":"29526279-19910531-2046665","span":{"begin":776,"end":778},"obj":"19910531"},{"id":"29526279-6268660-2046666","span":{"begin":956,"end":958},"obj":"6268660"},{"id":"29526279-3120465-2046667","span":{"begin":960,"end":962},"obj":"3120465"}],"text":"Our results provide some suggestions as to where the sickle mutation might have originated. Descendants of the Y chromosome haplogroup E1b1a-V38 migrated across the Sahara from east to west,49 possibly around 19,000 years ago.50 E1b1a1-M2 most likely did not originate in eastern or northeastern Africa, but where it originated in either western or central Africa is unclear.49 Accordingly, the sickle mutation most likely did not occur in eastern or northeastern Africa. Our results indicate that the origin of the sickle mutation was in the middle of the Holocene Wet Phase, or Neolithic Subpluvial, which lasted from ∼7,500–7,000 BC to ∼3,500–3,000 BC. This time was the most recent of the Green Sahara periods, during which the Sahara experienced wet and rainy conditions.51 Our results thus support the Green Sahara as a possible place of origin of the sickle mutation. An alternative hypothesis is that the sickle allele arose in west-central Africa,13, 52 possibly in the northwestern portion of the equatorial rainforest."}