NASA/GISS: This map shows the 10-year average (2000-2009) temperature anomaly relative to the 1951-1980 mean. The largest temperature increases are in the Arctic and the Antarctic Peninsula.
Scientific American: The genetic evidence suggests that the effective population -- an indicator of genetic diversity -- of early human species back then... was about 18,500 individuals... That figure translates into a total population of 55,500 individuals, tops... The population, and thus its genetic diversity, faced a major setback about one million years ago. The finding is detailed in the January 18 issue of Proceedings of the National Academy of Sciences...
The effective population researchers estimate at about 18,500 reveals that the extent of genetic diversity... was between 1.7 and 2.9 times greater than among humans today.... The diminished genetic diversity suggests human ancestors experienced a catastrophic event.
Image source: NASA/GISS
