Madagascar, threatened 23 million years of evolution. «There are only 5 years left to reverse course»- Corriere.it

If all of Madagascar’s currently endangered species were lost, humanity would be guilty of the disappearance of more than 20 million years of evolution, 23 million to be exact. A span of time that surprised the researchers from the University of Groningen, the Naturalis Biodiversity Center, in the Netherlands and the Vahatra Association, in Madagascar who oversaw the study, published in Nature Communications (complete search here). The team, led by Luis Valente, looked into the risk of extinction of animal and plant species considered endangered according to the Red List of the International Union for Conservation of Nature. According to the authors of the research, there are only 5 years left to save Madagascar from the point of no return. “The estimated 23 million years represent a much wider time span than what previous studies have calculated for other islands – underlines Valente – such as New Zealand or the Caribbean”. For example, they are among the most threatened species the ring-tailed lemur and the aye-ayewhich we have come to know “up close” also thanks to the animated film “Madagascar”.

But how did this result come about? To quantify the ongoing risk, the researchers pieced together an unprecedented amount of data, which describe the evolutionary relationships between all the mammalian species that were present in Madagascar at the time of colonization, 249 in all (30 of which have already disappeared and more than 120 that could become extinct in the coming decades). Using computer simulations, the authors of the study were able to calculate the time it took for this biodiversity to evolve and the time it would take for evolution to “replace” all mammals in the event of extinction. The restoration of the species already lost in the area, the authors point out, would take about three million years, but the situation could take an even worse turn. Madagascar represents — in fact — an example of biodiversity unique in the world, with about 90 percent of the island’s endemic species, over two hundred species of mammals. More than half of these life forms, however, are considered to be in danger of life, mainly due to human presence (here the article “Biodiversity threatened if we do not stop the international trafficking of endangered animals”).

“In the coming decades – comments Valente – if immediate conservation actions are not taken, a wave of extinctions with a profound evolutionary impact is expected. However, with an adequate conservation program it would be possible to preserve over 20 million years of evolutionary history. We knew that Madagascar «represents a precious treasure in terms of biodiversity – conclude the authors – our work contextualizes the importance of these forms of life. The results underline the potential gains of nature conservation in Madagascar from a new evolutionary perspective».