Giant Ground Sloths evolved three different hours for the same reason

A recovery climate to cool the giants of people before people are likely to drive more animals to extinguish.

Now sloths Small, famous lazy plants transfers tropical canopies in rainforests. But for ten million years, South America is home to a weak variation of sloths. There are many giants living on the ground, with some behemoths approaching 5 tons of weight.

That dazzling size size is more interested Alberto Boscaini At the University of Buenos Aires in Argentina and his companions.

“The size of the body focuses on everything in biological characteristics of an animal,” says Boscaini. “It is a promise way to study evolution.”

Boscaini and his companions collect data in physical features, DNAs and proteins of 67 lost and living classes in sloth – to develop a family tree showing their relationships with evolution.

Researchers immediately removed the history of evolution, which covered a simultaneous 35 million years, and added information about every sloth and lifestyle. They also studied trends of evolutionary body size, which makes body mass estimates 49 of the ancient and modern sloth groups.

The results suggested the body’s body size is influenced by climate and housing changes. For example, some sloth genera began living in trees – similar to the sloths today – and flowing the size of the body while they did it.

Meanwhile, three different lines of sloths independently changed elephantine proportions – and as they did so within the million mountains made in South America.

“Giganism is more closely related to cold and dry climates,” says team member Daniel Casali At the University of São Paulo, Brazil.

Many of the various sloths lost in two stages: One of the 12,000 years ago and the other is about 6000 years ago, as Boscaini.

“These matches with the expansion of Homo Sapiensfirst across the American supernessinent, and later in the Caribbean, “he said – which some giant sloths live. Especially, the remaining species of sloth lives in trees so harder for people to hunt than many cords on the ground.

The idea that people are to blow death for ancient megafauna is well supported, as Thaasa the pansani At the University of New Mexico, not included in the study.

“However, in science, we need several lines of evidence to strengthen our hypotheses, especially with unresolved and more issues like extinction of megafauna,” he said. New evidence floods this story.

“The sloths have developed most of their history,” Casali said. “(The findings) taught us how a successful (group) can be easily easily.”

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