Population bottleneck
<p>Apr 9, 2009 10:24 PM
 
This is consistent with the <a href="/wiki/Toba_catastrophe_theory" title="Toba catastrophe theory">Toba catastrophe theory</a> which suggests that a bottleneck of the human population occurred c. 70,000 years ago, proposing that the human population was reduced to c.15,000 individuals<a href="#cite_note-Ancestors_Tale-4" title=""><sup class="reference" id="cite_ref-Ancestors_Tale_4-1">[5]</sup></a> when the <a href="/wiki/Lake_Toba" title="Lake Toba">Toba</a> <a href="/wiki/Supervolcano" title="Supervolcano">supervolcano</a> in <a href="/wiki/Indonesia" title="Indonesia">Indonesia</a> erupted and triggered a major <a href="/wiki/Natural_environment" title="Natural environment">environmental</a> change.
 
On the other hand, in 2000, a <i>Molecular Biology and Evolution</i> paper suggested a transplanting model or a 'long bottleneck' to account for the limited genetic variation, rather than a catastrophic environmental change.<a href="#cite_note-6" title=""><sup class="reference" id="cite_ref-6">[7]</sup></a> This would be consistent with suggestions that in sub-Saharan Africa numbers could have dropped at times<b> as low as 2,000, for perhaps as long as 100,000 years, before numbers began to expand again in the <a href="/wiki/Upper_Paleolithic" title="Upper Paleolithic">Late Stone Age</a><a href="#cite_note-7" title=""><sup class="reference" id="cite_ref-7">[8]</sup></a></b></p>