By ANERI PATTANI

Age-related changes in sleep patterns may have helped early humans survive by ensuring at least one person was always alert to nighttime threats.

Published: July 12, 2017 at 05:00PM

from NYT Science https://www.nytimes.com/2017/07/13/science/hadza-tanzania-sleep-grandparents-evolution.html?partner=IFTTT
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