A new study reveals that it would take three million years to recover the number of species that have gone extinct due to human presence on Madagascar and 20 million more to recover if species under threat die out.
From unique baobab species to lemurs, the island of Madagascar is one of the world's most important hotspots of biodiversity. Approximately 90 per cent of its species of plants and animals are found nowhere else.
A team of biologists and palaeontologists from Europe, Madagascar and the United States identified 249 species in total, 30 of which already are extinct.
Over 120 of the 219 species of mammals that remain on the island today are currently classified as threatened with extinction by the IUCN Red List, due to habitat destruction, climate change and hunting.
Using a computer simulation model based on island biogeography theory, the team, led by biologists from the University of Groningen (Netherlands), Naturalis Biodiversity Center (Netherlands), and the Association Vahatra (Madagascar) found that it would take approximately 3 million years to regain the number of mammal species that were lost from Madagascar in the time since humans arrived.
However, if currently threatened species go extinct, it would take much longer: about 23 million years of evolution would be needed to recover the same number of species. Just in the last decade, this figure has increased by several million years, as human impact on the island grows. The staggering time it would take to recover this diversity surprised the scientists.
Lead researcher Luis Valente said: "It was already known that Madagascar was a hotspot of biodiversity, but this new research puts into context just how valuable this diversity is. These findings underline the potential gains of the conservation of nature on Madagascar from a novel evolutionary perspective."