sábado, 2 de noviembre de 2013

Will climate change cause humans to shrink ?

Scientists have warned that future generations could be a lot shorter than people who are alive today. The unexpected revelation is based on research in to the size of mammals during previous periods of global warming known as hyperthermals. 

According to a team of scientist from the University of Michigan, a reduction in size appears to be a common evolutionary response to an increase in global temperatures. Two examples of such periods were studied, one that occurred 55 million years ago and another that took place 53 million years ago. In both cases there were clear indications that the change in temperature had a profound effect on the size of mammalian species.

"The fact that it happened twice significantly increases our confidence that we're seeing cause and effect - that one interesting response to global warming in the past was a substantial decrease in body size in mammalian species," said study leader Philip Gingerich. Bizarrely, fossil evidence from horses of the time indicated that they had reduced in size to something comparable to that of a small dog.

Over the next few thousand years following the climate's recovery however the animals gradually returned to their normal size.

source and credit  a unexplained-mysteries