Earlier we covered a news that due to global warming, Glacial Ice that was formed over 1,600 years melted just in 25 years. On the other side, it has also been reported that global warming will increase temperature each year after 2047. Undoubtedly, it goes without saying that global warming is increasing at an alarming rate and it has a great effect upon environment. And now, some US researchers are saying that it is global warming for which humans could become shorter.
For years, researchers have believed that around 55 million years ago, mammals such as primates and the groups that include horses and deer became much smaller during the Paleocene-Eocene Thermal Maximum (PETM), a period of warming. The PETM lasted about 160,000 years, and global temperatures rose an estimated 9 to 14 degrees Fahrenheit at its peak.
And now, U-M paleontologist Philip Gingerich and his team members who are from the University of New Hampshire, Colorado College and the California Institute of Technology, have found evidence that mammalian “dwarfing” also occurred during a separate, smaller global warming event known as Eocene Thermal Maximum 2 (ETM2) that occurred about 2 million years after the PETM, around 53 million years ago. The ETM2 lasted 80,000 to 100,000 years and resulted in a peak temperature increase of about 5 degrees Fahrenheit.
The researchers have found that mammals’ body size decreased during ETM2, but not as much as the dwarfism seen in PETM fossils. For example, the study of researchers has revealed that a lineage of early horses the size of a small dog, called Hyracotherium, experienced a body-size decrease of about 19 percent during ETM2. The same horse lineage showed a body-size decrease of about 30 percent during the PETM. After both events, the animals rebounded to their pre-warming size.
Gingerich, who is a professor of earth and environmental sciences, has said, “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.”
The researchers have presented their findings on Nov. 1, in Los Angeles at the annual meeting of the Society of Vertebrate Paleontology.
Source: Daily Mail