A mega-drought in Africa 140,000 years ago almost caused Homo sapiens to go extinct. It is estimated they went down to breeding individuals. They lived in caves in South Africa and repopulated causing a bottleneck and a(n) in human genetic diversity as compared to non-human primates.

600, decrease

Explanation:

A mega-drought in Africa 140,000 years ago almost caused Homo sapiens to go extinct. It is estimated they went down to 600 breeding individuals. They lived in caves in South Africa and repopulated causing a bottleneck and a decreass in human genetic diversity as compared to non-human primates.

600; decrease

Explanation:

Africa had a more extreme and widespread megadroughts about 140,000years ago than any previously known for that region. According to research, this extreme drought almost caused Homo sapiens to go extinct with significant out-of-Africa migration due to drying out of the world’s and Africa's largest tropical lake, Lake Victoria and the Nile river as well as Lake Tana in Ethiopia.

It is estimated that human populations just crashed as they went down to six hundred breeding individuals. These surviving individuals lived in caves in South Africa and repopulated causing a bottleneck and a decrease in study of human origin and genetic diversity as compared to non-human primates.

im going to go with b.