Climate change led to waves of mammal evolution
Washington: A novel study has identified six distinct, consecutive waves of mammal species diversity, or “evolutionary faunas” in the last 65 million years of natural history in North America.
And researchers suggest that climate change might have led to these changes.
“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Brown University evolutionary biology Professor Christine Janis.
“We show that the rise and fall of these faunas is indeed correlated with climatic change – the rise or fall of global paleotemperatures – and also influenced by other more local perturbations such as immigration events,” he stated.
Specifically, of the six waves of species diversity that Janis and her Spanish collaborators describe, four show statistically significant correlations with major changes in temperature.
The two transitions that show a weaker but still apparent correlation with the pattern correspond to periods when mammals from other continents happened to invade in large numbers, said Janis, who is the study’s senior and second author.
What the authors found is six distinct and consecutive groupings of mammal species that shared a common rise, peak and decline in their numbers.
For example, the “Paleocene fauna” had largely given way to the “early-middle Eocene fauna” by about 50 million years ago. Moreover, the authors found that these transfers of dominance correlated with temperature shifts, as reflected in data on past levels of atmospheric oxygen (determined from the isotopes in the fossilized remains of deep sea microorganisms).
By the numbers, the research showed correlations between species diversity and temperature change, but qualitatively, it also provided a narrative of how the traits of typical species within each wave made sense given the changes in vegetation that followed changes in climate.
The finding appeared online this week in the Proceedings of the National Academy of Sciences.
More from India
More from World
More from Sports
More from Entertaiment
- Revealed - How Indian Army hit terror camps across LoC!
- Pak forces will teach Zee News what real surgical strike is: Hafiz Saeed
- India used 'Cartosat 2c' satellite in surgical strikes against Pakistan
- Panel discussion on Hafiz Saeed's reaction after Indian Army surgical strikes
- DNA: Inside story of Indian Army's surgical strikes across LoC
- Hafiz Saeed threatens Zee News, says Pak forces will teach what real surgical strikes are
- Pak postpones SAARC Summit after five member states pull out of conference: As it happened
- After threatening Zee News, Hafiz Saeed says PM Modi, Ajit Doval staged `surgical strike drama'
- India's surgical strikes: Pakistan buries slain terrorists to hide evidence, asks Masood Azhar to go mum
- Who is Chandu Babulal Chauhan and why India wants to bring him back from Pakistan - Read