SEP 06, 2020 7:37 AM PDT

Climate Change Caused a Mastodon Migration

WRITTEN BY: Carmen Leitch

Around 11,000 years ago, megafauna that was roaming the earth began to go extinct. Mastodons were some of the largest land animals living on the planet at the time, and they migrated around present-day North America, from Alaska south to Mexico and east to Nova Scotia. They lived in swampy environments and mostly ate shrubs and low tree branches.

Scientists have now used a variety of techniques to show that environmental changes that came with the melting of glaciers had a significant impact on the movement of mastodons. The findings, which were reported in Nature Communications, used mitochondrial genomes that were reconstructed from the fossilized remains of 33 individual mastodons.

"The genetic data show a strong signal of migration, moving back and forth across the continent, driven, what appears to be entirely by climate," explained study author and evolutionary geneticist Hendrik Poinar, director of the McMaster Ancient DNA Centre. "These mastodons were living in Alaska at a time when it was warm, as well as Mexico and parts of Central America. These weren't stationary populations, the data show there was constant movement back and forth."

Researchers have long speculated about why they and 44 other large mammals went extinct. Many hypothesize that it was the combination of climate change, competition for food, and overhunting by humans. Temperatures have fluctuated repeatedly on Earth. Around 800,000 years ago, a dramatic shift happened; the ice sheets changed and regions that had once provided for animals like horses, bison, and mammoths began to shift toward generating sustenance for beaver, moose, and mastodon.

As the climate warmed and ice sheets melted, the mastodon moved with them into the northernmost parts of modern-day Alaska and the Yukon. These groups of mastodon had lots of room to roam, but less genetic diversity, which made them more vulnerable to change.

Mastodon fossil on display at the American Museum of Natural History. / Credit: American Museum of Natural History

"By looking genetically at these animals which lived for the last 800,000 years, we can actually see the make-up of these populations that made it up to the north. It's really interesting because a lot of species presently, like moose and beaver, are rapidly expanding their range northwards by as much as tens to hundreds of kilometers every century," said lead study author Emil Karpinski, a graduate student at the Ancient DNA Centre and the Department of Biology at McMaster University.

"Analysis of DNA preserved in these fossil mastodon bones gives us so much more information on how these now-extinct beasts lived and died in comparison to what we know based on traditional paleontological approaches. These data hold the key to our understanding of how ancient animal communities like mastodons adapted to changes in the past, and provide clues to how arctic ecosystems will respond to future warming scenarios," added study co-author Dr. Grant Zazula, a paleontologist with the Government of Yukon.


Sources: AAAS/Eurekalert! via McMaster University, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 03, 2021
Microbiology
A New Bacterial Defense System is Discovered
MAY 03, 2021
A New Bacterial Defense System is Discovered
Most DNA that we're familiar with is found in cells in a double-stranded form. So, many years ago, scientists were intri ...
MAY 11, 2021
Genetics & Genomics
Gene Therapy Trial for Severe Immune Disorder is Successful
MAY 11, 2021
Gene Therapy Trial for Severe Immune Disorder is Successful
Severe combined immunodeficiency (SCID), which virtually eliminates a patient's immune system, and severely affects thei ...
MAY 28, 2021
Genetics & Genomics
Some Biofilms Seem to Activate Cancer Genes
MAY 28, 2021
Some Biofilms Seem to Activate Cancer Genes
New research assessed bacterial and fungal biofilms, tenacious microbial communities that are tougher than small groups ...
JUN 10, 2021
Cell & Molecular Biology
Does Lithium Prevent Colon Cancer?
JUN 10, 2021
Does Lithium Prevent Colon Cancer?
Researchers found that a drug used in the treatment of mental illness can promote the fitness of healthy gut stem cells, ...
JUN 23, 2021
Genetics & Genomics
Expansive RNA Atlas Includes Coding & Non-Coding Molecules
JUN 23, 2021
Expansive RNA Atlas Includes Coding & Non-Coding Molecules
We'e sequenced the human genome, even the parts that are highly repetitive, don't code for protein, and are extremely ch ...
JUN 27, 2021
Cell & Molecular Biology
Organoids Reveal Common Mechanism Underlying Rare Disorders
JUN 27, 2021
Organoids Reveal Common Mechanism Underlying Rare Disorders
Genetic testing has shown that mutations in a gene called HUWE1 are connected to rare syndromes that cause developmental ...
Loading Comments...