Sun, Feb 09, 2020 - Page 5 News List

Research shows defects plagued last mammoths


The world’s last mammoths, sequestered on an Arctic Ocean island outpost, had serious genetic defects caused by generations of inbreeding that might have hampered traits such as sense of smell and male fertility in the doomed population, scientists said on Friday.

The genome of one of the last mammoths from Wrangel Island off Siberia’s coast showed that the population was riddled with deleterious mutations, they said.

They resurrected genes from this mammoth in a laboratory to find clues about the demise of the species.

Most mammoths are said to have gone extinct roughly 10,000 years ago amid a warming climate and widespread human hunting, but isolated populations survived for thousands of years after that.

The Wrangel Island population was the last, disappearing roughly 4,000 years ago.

The researchers compared the Wrangel mammoth’s DNA to that of two older mammoths, as well three Asian elephants, a close relative.

They pinpointed a collection of genetic mutations in the Wrangel Island mammoth and synthesized these genes in the laboratory to test their functionality.

They found problems with genes responsible for sperm production, smell, neurological development and a function involving the hormone insulin that is responsible for permitting glucose in the blood to enter cells to give them energy.

“We can activate those genes in the lab using cell culture and test whether they are functional or not. In this case not,” said evolutionary biologist Vincent Lynch of the University at Buffalo in New York, who led the study published in the journal Genome Biology and Evolution.

The sperm production-related mutations might have reduced fertility in an already shrinking population. The olfactory mutations might have harmed the ability to forage and to even smell the flowers that made up an important part of their diet.

“It is indeed a sad thing,” Lynch said. “Mammoths were literally huge and globally distributed, and this massive range was reduced to a tiny island in the Arctic Ocean before their extinction. It should be a warning about the consequences of climate change.”

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