Madagascar has long been known as a hotspot of biodiversity. Although it represents only one percent of the earth’s area, it is home to about three percent of all animal and plant species on the planet. But research suggests the island’s heyday of species development may be all but over.
“A staggering number of species are found only on Madagascar,” said Daniel Scantlebury, a Ph.D. student in biology, “but this research shows there are limits to the number of species the island can sustain, and Madagascar may currently be at those limits.”
Scantlebury’s paper is being published this week in the Proceedings of the Royal Society B.
Scantlebury analyzed the evolutionary records of seven groups of reptiles and amphibians that are found across the island, including tiny leaf chameleons (which can rest comfortably on a matchstick), colorful and charismatic day geckos (of television insurance ad fame), and the bizarre leaf-tailed geckos (whose tails are flat and leaf-shaped). By constructing evolutionary tree diagrams to compare the relative ages of the species, he found that there has been a noticeable decrease in the rate of new species formation on Madagascar since the island became isolated following its split from the Gondwana super-continent some 90 million years ago. This pattern is thought to result from adaptive radiation, the same process that produced Darwin’s finches.
Read more at: Phys.org