The human forced the elephant to remove its tusks and the swallow to shrink its wings

In 1859, Charles Darwin published his seminal work, which was to revolutionize the understanding of evolution: with The Origin of Specieshe exposed the mechanism of natural selection, explaining the progressive adaptation of species to their environment.

It is over a long time that the evolution of species is most evident, because we must wait several reproduction cycles before observing which characteristics persist. What about in the 21st^e century? In a world dominated and shaped, sometimes disfigured, by humans, how have animals adapted to us? Here are three examples of evolution in the face of various forms of human predation.

Defenseless elephants

Intensive poaching and the ivory trade have had a direct consequence on the morphology of African elephants: in Mozambique as in Tanzania, we now observe, in conservation centers aiming to restore this species massacred by poachers, numerous female elephants that are born with short tusks or no tusks at all.

This is simply because tuskless elephants are less likely to be targeted, and therefore survive and reproduce more easily. “This is a disastrous example of how human pressure could cause elephants to lose one of the things that make them so iconic”laments Tanya Smith, conservation specialist for WWF-UK.

Swallows with small wings

When it’s not poachers, it’s cars. The expansion of road traffic is a major danger for birds, which are often crushed in mid-flight by speeding cars: every year, hundreds of millions of birds die from a collision with a vehicle. In southwest Nebraska, the cliff swallow has adapted to this risk by developing shorter wings, which make it more agile and allow it to dodge automobiles more easily.

From escargots palots

The influence of human action can also be more indirect: with climate change, many animals have had to adapt to survive the sharp rise in temperatures. In the Netherlands, city snails have evolved lighter colored shells to cope with the heat. While urban centers can have temperatures more than 8°C higher than those in rural areas, small gastropods have mutated to survive.

“Snails inside a dark shell tend to heat up more, risking death from overheating, explains Menno Schilthuizen, a Dutch biologist. The pale color of the shell probably allows the snails to stay cool enough during the hottest summer days in the city.”