(December 8, 2019 at 6:22 pm)BrianSoddingBoru4 Wrote: 'Succumbed to catastrophe' isn't the same as 'destroyed by catastrophes', and a 'mass extinction' isn't remotely the same as all life being destroyed. There's always enough left over to be getting on with things.
I suppose I wasn't clear when I said there were problems with the Snowball Earth hypothesis. The 'problem' is that it is far from a settled question as to whether there ever was a snowball Earth. A majority of geologists - even those who support the hypothesis - agree that it doesn't explain enough, and there isn't enough evidence. Even in periods of extreme glaciation, it's likely that the tropics remained warm (well, warm-ish).
Boru
Yup. Around 74,000 years ago, humans almost went extinct, being reduced to a few thousand survivors (estimates vary).