By Tim Radford
LONDON, 24 August, 2015 – Man-made climate change is expected to have a “significant effect” on the wildlife of the planet. And, if fossil evidence is anything to go by, it could seriously alter the course of evolution.
The hunting habits of the wolf – ancestor of man’s best friend, the dog – evolved over millions of years to cope with profound climate change, according to new research.
Borja Figueirido, of the Department of Ecology and Geology at the University of Malaga in Spain, and colleagues report in Nature Communications that they examined the elbows and teeth of 32 native North American species of the dog family from between 39 million and 2 million years ago.
Ambush and pursuit
What they found was clear evidence that, in response to changing climate and foliage cover, dogs evolved from ambush predators that survived by surprising their prey, to pursuit predators that wore them down.
The story begins with a warm, wooded North America in which a canine creature with flexible forelimbs, and not much bigger than a mongoose, used stealth to surprise and pounce cat-like on its dinner. Ultimately, it gave way to animals like wolves, which could chase a deer all day.
In the course of those 37 million years, the climate cooled, the forests gave way to savannah and prairie, and the dog family began to evolve new strategies − including the short pursuit-and-pounce technique of the coyote or the fox, and the long-distance stamina hunting of the wolf.
“It’s reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores,” says Christine Janis, professor of ecology and evolutionary biology at Brown University in the US, and a co-author of the report. “Although this seems logical, it hadn’t been demonstrated before.”
The scientists backed up their conclusions by studying the teeth and forelimb structures of a wide range of hunting animals, including cheetah, hyena and wild dog in Africa, the tiger and snow leopard in Asia, and the jaguar, puma and wolverine in the Americas.
Their formal conclusion is that when things changed for the herbivores that shaped the landscape, the predators also responded.
Such research confirms the worries of wildlife conservationists that man-made climate change in response to rising levels of carbon dioxide in the atmosphere − as a consequence of the burning of fossil fuels − could seriously alter the evolutionary conditions and the ecosystems from which civilised humankind and its domestic animals emerged.
The scientists say their studies demonstrate that “long periods of profound climatic change are critical for the emergence of ecological innovations, and could alter the direction of lineage evolution”. – Climate News Network