http://www.history.com/shows.do?episodeId=276811&action=detail
[snip] 10000 B.C. was a time of cataclysmic change on Earth. Extreme climactic fluctuations hurled the planet into a minor ice age; megafauna like the saber-toothed tiger and woolly mammoth were suddenly becoming extinct; and early humans began to inhabit North America. Cold and hungry their fragile communities undertook perilous hunting expeditions. The slaughter of a single mammoth weighing nearly ten tons could be the difference between survival and death. JOURNEY TO 10000 B.C. brings this unique and thrilling period to life and investigates the geologic and climate changes that scientists are just beginning to understand. In a major forensic investigation HISTORY visits early human archaeological sites to uncover fossilized bones ancient dwellings and stone weapons and uses state-of-the-art CGI to recreate the treacherous mammoth hunts and the devastating impact of a comet colliding with Earth. [end]
And I agree with you that we're not talking about a gradualist phenomenon.