ForGod'sSake: One problem that jumped out at me was the ~35,000 year old tusks MAY have been peppered with fragments ~13,000 years ago. Not likely for the simple reason that once exposed to the air, tusks begin to deteriorate. So what would have HAD to happen is the ~20,000 year old tusks MUST have been exposed ~13,000 years ago, THEN resealed to preserve them for another ~13,000 years. Did I miss something?That doesn't make sense to me either, I think the author of the article punched that up perhaps without realizing the significance (actually lack thereof) of the speculation.
43north: But wait! The extinction of the mammoths was due to greedy, evil pre-historic humans over-hunting them. Now this?:'D
gleeaikin: Note the date of 35,000 years before present. Also in the article there was something about 20,000 year earlier.The article speaks of the event 13,000 years ago, and of the earlier event 35,000 years ago (iow, 22,000 years earlier than the more recent one).
gleeaikin: It is entirely possible there was more than one of these events.The bombardment happened as the (last?) wave of debris arrived from a supernova explosion long before. There were a series of (three? Blam?) different bombardments which arrived at different times (due to velocity differences) from the same supernova explosion. The book concentrates on the Pleistocene mass extinction in the Americas. There were survivors, but they were in small isolated groups which just by chance were not bombarded, so the megafauna were effectively driven to extinction. The earlier events will be further studied, and this is the latest finding they've announced. There will be more.
I had gotten the (wrong?)impression from other articles/posts on this subject, that Firestone et.al had moved away from a supernova explanation as a cause of the disturbance in the force. No?