The theory that the great beasts living in North America 13,000 years ago were killed off by a space impact can now be discounted, a new study claims.
Mammoths, giant bears, big cats and the like disappeared rapidly from the fossil record, and a comet or asteroid strike was seen as a possible culprit.
But tiny diamonds said to have been created in the collision have been misinterpreted, a US-UK team says.
Without these diamonds, the theory falls, the group tells PNAS journal.
"This was really the last pillar for this theory and I think it's time now everyone moved on," said co-author Professor Andrew Scott, from Royal Holloway, University of London, UK, told BBC News. ...
"We looked for these diamonds and we couldn't find them," said Professor Scott. "But not only that, [the proponents of the theory] have misinterpreted what are really just aggregations of carbon.
"There were frequent low-temperature fires all through this period - this is no big deal. And what happens is that the carbon in molecules gets re-ordered and this happens in very small domains, less than micron-sized areas.
""It's not a high-temperature phenomenon; it happens at low temperatures. Obviously, what they've done is take that material and identified these domains as diamonds when they're not."
The proponents of the impact theory are not prepared to let go of their ideas just yet, however.
Dr Douglas Kennett of the University of Oregon, Eugene, US, told Science Magazine that the research featured in PNAS had been looking in the wrong places.
"The Daulton et al claim that we have misidentified diamonds is false and misleading," he said.
And geoscience consultant Allen West added that Daulton and colleagues had not followed the same protocols and therefore it was no surprise they had came up with a blank.
"They did say that they looked in some carbon spherules but we looked at 10-15 per layer and specified that in our methodology, and they only looked at 'one to several' - that's their quote. They didn't understand what they were supposed to be looking for."
"They looked at charcoal but we never mentioned that we ever found diamonds in the charcoal," he told BBC News.
via BBC News - Mammoth-killing space blast 'off the hook'.
Most people do not realize that scientists are constantly trying their best to prove each other wrong. Unlike religion, science progresses because someone wins and someone loses these little debates based on the evidence.
Can you imagine any religion doing a mutually agreed upon discovery process and then admitting it had wrong beliefs compared to a different religion? I know of no paradigm shifts in religion.
People suspicious of scientists being in on some vast conspiracy (global warming, age of the earth, evolution, etc.) don't understand the process that resulted in the shared views.
It boils down to this: "Because someone said so" is not good enough evidence for a scientist.