[autokad]

ice ages didn't happen until after the asteroid strike. Antarctica moving into the south pole is likely a large part of it, but they don't really understand ice ages that well TBO. Anyhoo, the Earth was a lot warmer prior to the strike and we have been going through extinction events every 100k years.

[mkl]

By "the" asteroid strike I'm guessing you mean the one 66M years ago? There were definitely ice ages before that, likely including one or more Snowball Earth phases (the whole surface frozen): https://en.wikipedia.org/wiki/Snowball_Earth.