Arrival· Where Sapiens lives

Southwest Asia

50 ka

About 50,000 years ago, the expansion from which all present-day populations outside Africa descend passed through Southwest Asia, and unlike earlier exits it did not recede.

Region through which passes the expansion from which present-day populations outside Africa proceed, and which, unlike earlier exits, did not recede.

What the evidence shows

Of that expansion only three male lineages survive, identified by Y-chromosome haplogroups: D, rare; C, uncommon; and FT, today predominant in most populations outside Africa. Phylogeography, which relates the structure of a genetic genealogical tree to the geographical distribution of its branches, places the origin of all three in East or South-East Asia, between 55,000 and 50,000 years, and not in western Eurasia, where a simple model of expansion from a source close to Africa would have placed it. All non-African populations moreover carry about 2 per cent Neanderthal DNA issuing from the same episode. The reduction to three surviving lineages gives the measure of how narrow the passage was.

Dating & uncertainty

The genomes of present-day populations outside Africa proceed almost entirely from this single expansion. Other groups had reached the region much earlier without leaving detectable descent.