Rapid metabolism change helped mammals to thrive in colder climate

Rapid metabolism change helped mammals to thrive in colder climate
Credit: NASA/PAC

Hedgehogs, rabbits, primates and even giraffe have all benefited in the evolutionary race due to their ability to adapt their metabolism to cope with a changing climate, according to new research.

A new study, published in Nature, reveals that the ancestors of mammals benefited in the evolutionary race owing to their ability to adapt their beyond the constraints imposed by temperature. They were able to colonize colder environments or high latitudes, allowing them to thrive when the Earth's climate cooled.

The basal metabolic rate of animals (the rate at which energy is used to maintain the body) was previously thought to be intimately linked with an animal's body temperature. However, this research shows mammals were able to decouple this relationship to allow their metabolism to evolve rapidly and adapt over 165 million years.

Dr. Jorge Avaria-Llautureo, at the University of Reading and lead author of the study, said: "The research shifts the emphasis to understand the origin of mammalian metabolic diversity as a response to the rate at which they lose heat to the environment.

"Colder environments increase the rate of heat loss from mammals and, to maintain the body temperature constant, this loss is subsequently compensated for by increasing the metabolic rates as long as resources are available to fuel the metabolic elevation."

Previous research worked on the principle that body temperature and metabolism were closely aligned because metabolism is the primary source of heat and the body temperature itself affects the metabolic rates.

However, the new study found that was able to quickly adapt animals' metabolisms irrespective of body temperature—this was true for over 90 percent of ancestral mammals including bats, carnivorous, hedgehogs, marsupials, primates, rabbits, rodents, and even-toad ungulates.

Dr. Chris Venditti, evolutionary biologist at the University of Reading and co-author of the paper, said: "The paper has challenged the assumption of ecological and evolutionary theories that basal metabolism evolved hand-in-hand with body temperature. These physiological traits evolved under distinct selection pressures causing different routes to their modern diversity. It also helps us to understand the evolutionary advantages that have led to the diversity of the energy expenditure in mammals."

The paper also looked at the evolutionary trajectory of metabolism in birds. They found that basal metabolic rates and body temperature were also unlinked at least 36 percent of the time, however, avian metabolism was not affected by changes in ambient temperature.

Dr. Avaria-Llautureo said: "The difference we saw in birds is most likely because feathers allow more heat retention than fur. Their feathers helped them to isolate their internal environment and to keep their physiology more constant than mammals in an ever colder historical environment."

Mammals that particularly benefited from the evolutionary advantage include:

  • hedgehogs (order Eulipotyphla)
  • even-toed ungulates (order Artiodactyla)
  • carnivorous (order Carnivora)
  • primates (order Primates)
  • rabbits (order Lagomorpha)
  • rodents (order Rodentia)

Explore further

Geese reduce metabolic rate to cope with winter

More information: Jorge Avaria-Llautureo et al. The decoupled nature of basal metabolic rate and body temperature in endotherm evolution, Nature (2019). DOI: 10.1038/s41586-019-1476-9
Journal information: Nature

Citation: Rapid metabolism change helped mammals to thrive in colder climate (2019, August 15) retrieved 19 September 2019 from https://phys.org/news/2019-08-rapid-metabolism-mammals-colder-climate.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Aug 15, 2019
The process of shivering from the cold temperatures induces the body to increase its metabolism, which in turn requires more food. Adaptation to the cold temperatures come with more availability of food to fuel the body's requirements such as increase of blood flow to extremities and the skin.
A layer of fat under the skin also helps to increase warmth to the skin layers and blood vessels such as capillaries provide warm blood to help prevent freezing.
Adaptability to differing temperatures and other weather conditions determine where animals, including man, are most unsusceptible to changes that would ordinarily require moving to another location that is most favourable to their survival.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more