
© Tony Hutchings/Getty ImagesLand of the giants. For your great, great grandchildren, cows might be the biggest megafauna around.
In a couple of hundred years the largest animal walking on land may well be a cow, new modelling predicts.
A paper published in the journal Science uncovers for the first time a startling
correlation between human migration and the extinction of large animals.The link between the loss of big creatures and the spread of
Homo sapiens and other hominin species was well established by the time humans left Africa around 125,000 years ago, researchers led by biologist Felisa Smith of the University of New Mexico, US, found.
With no indication that the trend is abating, the team predicts that all currently endangered large terrestrial species will pass within the next couple of centuries, leaving cows, at an average weight of 900 kilograms, the biggest things left.
To make their finding, the scientists used two data sets. The first was a global record of all terrestrial species known, and classified according to body mass and diet, for the late Quaternary period, which started around a million years ago. The second was a similar record for all known species in the Cenozoic period, which started 66 million years ago and is known colloquially as the Age of Mammals.
Comment: It seems that the tree has just reached that age, but it's admirable that people are trying to help all the same: