London, Feb 4 (IANS) Fresh evidence rebuts the theory that an asteroid wiped out prehistoric humans known as Clovis, or caused abrupt climatic changes, says a new study.
Researchers from the Royal Holloway University, Sandia National Lab and 13 US and European universities, argue that other explanations must be found for the apparent disappearance of the prehistoric humans.
Clovis is the name archaeologists have given to the earliest human culture in the North American continent. It is named after the town in New Mexico, where distinct stone tools were found in the 1920s and 1930s, the journal Geophysical Monograph Series reports.
Researchers argue that no appropriately sized impact craters from that period have been discovered, and no shocked material or any other features of impact have been found in sediments, according to a Royal Holloway statement.
They also found that samples presented in support of the impact hypothesis were contaminated with modern material and that no physics model can support the theory.
"The theory has reached zombie status," said Andrew Scott, professor of earth sciences at Royal Holloway. "Whenever we are able to show flaws and think it is dead, it reappears with new and equally unsatisfactory arguments."