FEB 10, 2020 10:19 AM PST

The Broken Genes of the Last Woolly Mammoths

WRITTEN BY: Carmen Leitch

The last woolly mammoths are thought to have died out around 4,000 years ago in a remote area off the Siberian coast, called Wrangel Island. Scientists have now used genetic data to learn more about how these massive herbivores became extinct. It has been suggested that the final members carried a variety of genetic defects that interfered with their reproduction, development, and sense of smell. In this new research, the investigators confirmed that the last mammoth's genes weren't functioning properly. The findings have been reported in Genome Biology and Evolution.

A representation of a woolly mammoth / Credit: Pxhere

"The key innovation of our paper is that we actually resurrect Wrangel Island mammoth genes to test whether their mutations actually were damaging (most mutations don't actually do anything)," said the lead study author Vincent Lynch, Ph.D., an evolutionary biologist at the University at Buffalo.

If a population goes into rapid decline, the dwindling numbers may begin to interbreed, which reduces the genetic diversity in their descendants, further endangering the animals. Harmful genetic mutations can then build up in the species.

"Beyond suggesting that the last mammoths were probably an unhealthy population, it's a cautionary tale for living species threatened with extinction: If their populations stay small, they too may accumulate deleterious mutations that can contribute to their extinction," added Lynch.

Lynch worked with an international team of researchers to compare DNA from a Wrangel Island woolly mammoth to genetic material from two mammoths that were part of larger, older populations as well as three Asian elephants. The scientists learned that the Wrangel Island mammoth DNA had unique mutations. After synthesizing all of the mutated genes, the researchers generated the proteins encoded by those genes and tested their ability to interact with their normal partners. This was done for genes that play a role in several critical functions, including detecting odors.

"We know how the genes responsible for our ability to detect scents work. So we can resurrect the mammoth version, make cells in culture produce the mammoth gene, and then test whether the protein functions normally in cells. If it doesn't -- and it didn't -- we can infer that it probably means that Wrangel Island mammoths were unable to smell the flowers that they ate," Lynch explained.

This work has confirmed and built on previous data. "The results are very complementary," Lynch said. "The 2017 study predicts that Wrangel Island mammoths were accumulating damaging mutations. We found something similar and tested those predictions by resurrecting mutated genes in the lab. The take-home message is that the last mammoths may have been pretty sick and unable to smell flowers, so that's just sad."

Sources: AAAS/Eurekalert! via University at Buffalo, Genome Biology and Evolution

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 02, 2020
Genetics & Genomics
In a First, Researchers Edit Cephalopod Genes
AUG 02, 2020
In a First, Researchers Edit Cephalopod Genes
Using the CRISPR-Cas9 gene-editing tool, researchers have knocked out a gene in a cephalopod for the first time.
SEP 14, 2020
Cancer
MiR-107 and Its Role in Radiosensitivity in Prostate Cancer
SEP 14, 2020
MiR-107 and Its Role in Radiosensitivity in Prostate Cancer
It is often unknown whether a patient will respond to a treatment until it is in full swing. New research is attempting ...
SEP 09, 2020
Microbiology
Changing How We Think of Drug Resistance in Fungi
SEP 09, 2020
Changing How We Think of Drug Resistance in Fungi
It's been estimated that fungal infections cause more than one million deaths worldwide, and many more are affected.
SEP 16, 2020
Genetics & Genomics
Epigenetic Defects Are More Common in People Than Thought
SEP 16, 2020
Epigenetic Defects Are More Common in People Than Thought
The genome still holds many secrets, some of which probably have a direct relationship to human disease. Beyond genes th ...
SEP 22, 2020
Genetics & Genomics
Friedreich's Ataxia Successfully Treated in a Mouse Model
SEP 22, 2020
Friedreich's Ataxia Successfully Treated in a Mouse Model
Friedreich's ataxia causes degeneration in the peripheral nervous system, and movement is progressively impaired over ti ...
OCT 01, 2020
Microbiology
Investigating the Origins of a Cholera Epidemic
OCT 01, 2020
Investigating the Origins of a Cholera Epidemic
Cholera is an intestinal infection caused by Vibrio cholerae. Cholera has been a scourge throughout human history, and i ...
Loading Comments...