When blowflies and flesh flies settle on dead animals, they aren’t just feasting on the carrion, they are in fact sampling their DNA. Scientists have demonstrated that this DNA persists long enough to be sequenced, allowing them to gain a quick and cost-effective snapshot of mammal diversity in otherwise inaccessible rainforest environments.
According to a new survey of Brazil’s Atlantic forests, mammal extinctions are occurring at least twice as fast as previous estimates suggested. Jaguars, lowland tapirs, woolly spider-monkeys, and giant anteaters are almost absent from Brazil’s northeastern forests, which are among the most ancient and threatened tropical ecosystems on Earth.
It would seem logical that periods of global warming in Earth’s history started the extinction pulses that defined the geological record. However, that’s not the case as a report that was published this week proves. The warming of Earth is accompanied by an increased biodiversity. That doesn’t mean that the mass extinction pulses won’t take place.
One in five of Earth’s invertebrate species are currently threatened with extinction. These creatures represent 99% of the biodiversity on Earth. Until now, scientists haven’t attempted a comprehensive review of the conservation status of this many species. Less than 1% of invertebrates had been assessed by the International Union for Conservation of Nature (IUCN).
The analysis of the weapons used by the indigenous people of the Gilbert Islands in the central Pacific Ocean, which primarily use shark teeth, indicate that at least three species of shark have disappeared from the waters near the islands. Joshua Drew, a conservation biologist at Columbia University in New York, studied the weapons housed in the collection of the Field Museum of Natural History in Chicago, Illinois, and presented his findings at the 2012 Ecological Society of America’s Annual Meeting in Portland last week.
The greatest mass extinction pulse was the Permian-Triassic extinction event, and it happened about 250 million years ago, nearly wiping out life on Earth. It was Earth’s most severe extinction even, with 96% of all marine species and 70% of all terrestrial vertebrate species becoming extinct. It is the only known mass extinction that affected insects, 57% of all families and 83% of all genera were extinguished.