0:00
the history of human populations has
0:02
been shaped by several bottleneck events
0:04
that drastically reduce their numbers
0:06
bottlenecks in human history refer to
0:09
periods when the human population
0:11
drastically declined due to natural
0:13
disasters climate changes or other
0:16
catastrophic events reducing genetic
0:19
diversity and impacting evolutionary
0:22
Pathways one of the significant
0:24
bottlenecks is the early to Middle Pine
0:26
transition around 900 to 600 thousand
0:30
years during this period severe climatic
0:33
fluctuations including prolonged glacial
0:36
Cycles may have reduced early human
0:38
populations to extremely low numbers of
0:41
up to a thousand individuals in Europe
0:44
during the last glacial maximum 20,000
0:46
years ago extreme cold and arid
0:49
conditions during the peak of the Ice
0:51
Age may have reduced habitable land and
0:53
resources leading to localized
0:56
bottlenecks in human populations around
