Paleontologists have documented how dramatic shifts in climate have led to dramatic shifts in evolution.
One such event, the Grande Coupure, was a wipeout of many European mammal species 33.9 million years ago when global temperatures and precipitation declined sharply. What has been puzzling is that during the same transition between the Eocene and Oligocene periods, North American mammals fared much better.
The rise of the Rockies extended from British Columbia to Nevada in three phases between 56 and 23 million years ago. The rising mountains dried out the interior, preparing mammals for a major climate change event 34 million years ago, researchers say. European mammals were not so prepared.
Courtesy of Eronen et. al.
A new study explains why: the rise of the Rocky Mountains, already underway for millions of years, had predisposed populations to adapt to a cold, dry world.
'Regional tectonically driven surface uplift resulted in large-scale reorganization of precipitation patterns, and our data show that the mammalian faunas adapted to these changes,' write the study authors, including Christine Janis, professor of ecology and evolutionary biology at Brown University, in the Proceedings of the Royal Society B. 'We suggest that the late Eocene mammalian faunas of North America were already 'pre-adapted' to the colder and drier global conditions that followed the EO climatic cooling.'
The data in the study led by Jussi Eronen of the Senckenberg Research Institutes in Germany and the University of Helsinki in Finland, come from the authors' analysis of the fossil record of the two continents, combined with previous oxygen isotope data that reveal precipitation patterns, and tectonic models that show the growth of the Rocky Mountains. Specifically, the study shows that the rise of the range spread south in three phases from Canada starting more than 50 million years ago, down through Idaho, and finally into Nevada by 23 million years ago.
In the meantime, fossil mammal data show, precipitation in the interior regions dropped, and major shifts in mammal populations, such as an almost complete loss of primates, took place. Estimated rainfall based on plant fossils in Wyoming, for example, dropped from about 1,200 millimeters a year 56 million years ago to only 750 millimeters a year about 49 million years ago.
But across the region these correlated shifts occurred over tens of millions of years, leaving a well-adapted mix of mammals behind by the time of the Grand Coupure 34 million years ago.
In Europe, meanwhile, tectonic developments weren't a major factor driving local climate. When the global climate change happened, that continent's mammals were evolutionary sitting ducks. Other studies have already suggested that Europe's mammals were largely overrun and outcompeted by Asian mammals that were already living in colder and drier conditions.
Eronen said the findings should elevate the importance of collaboration across disciplines, for instance by integrating geoscience with paleontology, in the analysis of broad evolutionary patterns.
'Our results highlight the importance of regional tectonic and surface uplift processes on the evolution of mammalian faunas,' they wrote.
In addition to Eronen and Janis, the paper's other authors are C. Page Chamberlain of Stanford University and Andreas Mulch of the Senckenberg Institutes and Goethe University in Germany.
David Orenstein | EurekAlert!
Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center
Synthetic nanoparticles achieve the complexity of protein molecules
24.01.2017 | Carnegie Mellon University
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Earth Sciences
24.01.2017 | Life Sciences
24.01.2017 | Physics and Astronomy