Mass_Extinction_At_The_End_Of_The_Last_Ice_Age

Mass Extinction At The End Of The Last Ice Age Scientists continue to debate the causal factors involved in the extinction of large land mammals at the end of the last Ice Age, about 11,000 years ago. There are three leading schools of thought on this debate: human hunting ("Kill"), climate change ("Chill") or plague ("Ill"). A fourth school of thought holds that many factors converged to cause mass extinction during the last ice age (“Combination”). (BBC Evolution Weekend). The proponents of the “Kill” theory contend that over-hunting directly caused the mass extinction of the large Pleistocene mammals in North America or that perhaps over-hunting eliminated a "keystone species" and this ultimately led to extinction. This theory proposes that humans migrated into North America across the Bering Land Bridge where they encountered favorable conditions (space and game) that allowed the human population to increase exponentially. Paul McNeil, a Ph.D. candidate in paleontology at the University of Calgary and supporter of this theory, said: “Environment and climate change were definitely factors in the extinction event, but there had been numerous instances of glaciers advancing and retreating during the Pleistocene, and this is the only time we see a megafaunal extinction. The arrival of humans is the only real new factor" (Mayell, Hillary. extinction, theory, humans, human, pleistocene, extinctions, evolution, species, ice, age, weekend, north, new, mammals, last, climate, change, caused, bbc, years, university, thought, kill, grayson, fiedel, factors, factor, end, during, diseases, climatic, been, arrival, animals, america, tenets