Siberian Mammoths Originated in America

animan wrote: »

Would the mammoths not have interbred and made it near impossible to differentiate between bloodlines?

Well yes they quite probably did interbreed.
It was once taught that the Eurasian and American strains had not interbred. But now studying the DNA has shown that around 300,000 years ago American mammoth DNA shows up in the Eurasian mammoth gene pool, indicating that some American mammoths migrated back into Siberia (they originally moved to America around 700,000 years ago).
Interestingly the Eurasian stand of mammoth went extinct about 40,000 years ago. It is not clear whether they were out-competed or simply 'out-bred' by the American mammoths. Or perhaps a disease carried over by the American mammoths wiped them out. Apparently the American strain went on to live in Siberia for some 30,000 years after the Eurasian mammoths seem to have gone extinct.

Of course as with any such study there has been opposition. Several scientists point out that these conclusions are based on too small a quantitative survey of DNA and thus the findings are in no way conclusive.

Does this help, or have I made things even more complicated?