The dating of the earliest successful migration modern humans out of Africa is a matter of dispute . It may have pre - or post-dated the Toba catastrophe , a volcanic super eruption that took place between 69,000 and 77,000 years ago at the site of present-day Lake Toba . According to Michael Petraglia , stone tools discovered below the layers of ash deposits in India at Jwalapuram , Andhra Pradesh point to a pre-Toba dispersal . The population who created these tools is not know with certainty as no human remains were found . An indication for post-Toba is haplo-group L3 , that originated before the dispersal of humans out of Africa , and can be dated to 60,000 – 70,000 years ago , " suggesting that humanity left Africa a few thousand years after Toba . " It has been hypothesized that the Toba supereruption about 74,000 years ago destroyed much of India 's central forests , covering it with a layer of volcanic ash , and may have brought humans worldwide to a state of near-extinction by suddenly plunging the planet into an ice-age that could have lasted for up to 1,800 years . If true , this may " explain the apparent bottleneck in human populations that geneticists believe occurred between 50,000 and 100,000 years ago " and the relative " lack of genetic diversity among humans alive today . " Since the Toba event is believed to have had such a harsh impact and " specifically blanketed the Indian subcontinent in a deep layer of ash , " it was " difficult to see how India 's first colonists could have survived this greatest of all disasters . " Therefore , it was believed that all humans previously present in India went extinct during , or shortly after , this event and these first Indians left " no trace of their DNA in present-day humans " – a theory seemingly backed by genetic studies
Toba catastrophe
Toba catastrophe theory
Peopling of India