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Humans would have accelerated the extinction of island animals such as dwarf elephants and giant rats



The arrival of our species on islands with unique animal species has significantly increased extinction rates. Hunting, habitat destruction and disease invasion are the main causes.

Humans are partly responsible for the increasing extinction of animal species on unusually sized islands. Like the little elephant of Cyprus or the giant mouse of the West Indies According to a new study published by scientific journals.

The aforementioned animals are the so-called “Island effect” a rule in evolutionary biology that explains that large species tend to shrink in size on an island, and small species tend to make it larger.

A recent study examined 1,231 extant and 350 extinct species of dwarf and giant island mammals over the past 23 million years.conspicuous among animals Hippopotamus, buffalo and little wolf.

Extinction rate compared to humans

The study authors concluded that the risk of extinction was higher among species that underwent more physical alterations compared to their continental relatives. And the arrival of modern humans on the island increased the extinction rate by more than tenfold.

The wreckage of a small elephant the size of a pony.
The wreckage of a small elephant the size of a pony.

“Unfortunately, the steepness of the extinction curve that began with the arrival of the first human travelers and followed with subsequent waves of colonization It has become even more pronounced in recent decades. said lead author Roberto Rozzi, a paleoecologist at the Martin Luther University in Halle-Wittenberg, Germany.

Island effects and seeds

Covering less than 7% of the Earth’s surface, islands are home to up to 20% of terrestrial species and support unique evolutionary dynamics.

Large species have limited habitat and food resources compared to the mainland, so there is an evolutionary pressure to reduce their size.

Smaller species, by contrast, are more likely to freed from the constraints of evolution reflected in its size.

“Being an island nation, the islands are home to all kinds of strange and wonderful animals, many of which are already extinct. and nearly 50% of them are threatened with extinction. Incredibly depressing. ” Kate Lyons, a paleoecologist at the University of Nebraska-Lincoln and study co-author, said:

rare endangered species

Currently, species such as the Tamaraw dwarf buffalo on Mindoro Island in the Philippines are 21% larger than their closest continental relatives, and spotted deer on the islands of Panay and Negros in the Philippines are 26% larger. The Jamaican hutia is four times the size and is endangered.

On the Indonesian island of Flores, described as a laboratory for the island effect, it was inhabited by dwarf elephants, giant rats, giant storks, and dwarf human species. Homo floresiensis Known as the “Hobbit”, he is only 106cm tall. Hobbits disappeared some 50,000 years ago, shortly after our species, Homo he sapiens, arrived on Flores.

anthropogenic extinction

Our species plays a leading role through hunting, habitat destruction, disease invasion and other invasive predators, destabilizing pristine island ecosystems. Even the early arrival of extinct human species on the island, such as Homo erectus, coincided with a doubling of extinctions.

“We always have to be careful about stating actual causality, especially since many different things tend to happen at the same time,” said study co-author Jonathan Chase of the German Center for Integrated Biodiversity Research. I’m here.

“However, our results show very convincingly that the extinction rate on these islands increased dramatically following the arrival of modern humans. This is, at least historically, the case for many In the case of , overfishing was the cause.

Source: Biobiochile

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