The curators found a core collected off the Horn of Africa in 1965 from the R/V Robert D. Co-author de Menocal studied and dated the layers of the 1965 core and found it had sediments going back as far as 200,000 years.
At the UA, Tierney and Paul Zander teased out temperature and rainfall records from the organic matter preserved in the sediment layers.
Perhaps people left because the environment was deteriorating,” she said.
“There was a big shift to dry and that could have been a motivating force for migration.” “It’s interesting to think about how our ancestors interacted with climate,” she said.
Tierney said before this research there was no record of the climate of northeast Africa back to the time of human migration out of Africa.