What Killed the Woolly Mammoths?

Last week, Francis and I visited UW Madison's free geology museum where they have several skeletal remains in addition to fossils and mineral specimens. With the woolly mammoth in my recent memory, this article from the BBC caught my eye.

The article reports on new research published in Proceedings of the National Academy of Sciences that disproves previously held notions about the meaning of nanodiamonds (incredibly small diamonds) found in sediments that date to the period of history 12,900 years ago that saw the rapid extinction of large creatures and human settlers across north america at the beginning of the cooling period known as the Younger Dryas. 

The presence of nanodiamonds in the sediment had led researchers to believe that an impact of something from space had disrupted the natural environment and led to the extinction. However, the new research seems to disprove the impact from space theory, as the strongest evidence - the nanodiamonds - have been shown to be just aggregations of carbon, not proof of a collision with a space-rock. 

The research isn't the final word on the issue however, because some proponents of the collision from space theory have claimed that the research from PNAS was looking at the incorrect sediments and didn't accurately study the nanodiamond evidence. 

Truly, the issue is an example of how the very nature of science, that it is always changing and adapting, can cause confusion. Researchers simply won't always agree based on the evidence that they have witnessed, which can make it very difficult for the public to draw conclusions as new findings are constantly introduced.