Of all the species that have ever lived, more than 99% are now extinct. Most of them quietly disappeared during periods of'background extinction', whereby a handful of species become extinct every 100,000 years or so. But there were also occasions when extinction rates increased rapidly in short periods of time and wiped out a significant proportion of all life on Earth. The majority of past extinctions are associated with carbon dioxide from volcanoes causing rapid global warming. These are known as mass extinctions.
Two of Earth's five mass extinction events - times when more than half of the world's species died - resulted in the survival of a low number of'weedy species', new research has found. These so-called weedy species spread around the world as Earth recovered from these dramatic mass extinctions, which involved suspected volcanic eruptions. Researchers say their findings are significant because they could shed light on modern high extinction rates and how biological communities may change in the future. The mass extinction at the end of the Permian (252 million years ago) was the largest in Earth's history. The study, conducted by researchers at North Carolina State University and the North Carolina Museum of Natural Sciences, involved examining fossil records of almost 900 vertebrate species dating back between 260 and 175 million years ago - from the late Permian through the Triassic and early Jurassic periods.
It's been called the worst extinction in our planet's history, wiping out nearly all life on Earth 252 million years ago. But, according to a new study, 'The Great Dying' might not have been as bad as once thought. While previous research found this event led to the extinction of up to 96 percent of all marine species, the new calculations estimate the losses may have been much lower, with the actual extinction rate at around 81 percent, suggesting instead that'life did not almost disappear.' The Permian-Triassic mass extinction – also known as the Great Dying – lasted for roughly 60,000 years and is often blamed for erasing up to 96 percent of marine life. According to the new calculations, 90 orders and 220 families of marine life likely survived the Permian-Triassic extinction event, as 81 percent of species were killed off.
In a new study, a group of researchers used an ancient mass extinction event as an analog to demonstrate how the current course of global climate change could prove devastating for marine life in the future. Some 182 to 174 million years ago, during the early Jurassic era, a mass extinction event referred to as Toarcian Oceanic Anoxic Event or T-OAE occurred. The event, triggered by the decline in oxygen levels prevailing in the oceans around the globe, marked the end of many sea organisms living during that time. It is well known today that rising global temperatures are one of the biggest reasons behind the declining levels of oxygen in oceans around the globe. As the amount of carbon dioxide increases in the atmosphere, the problem of climate change is fueled, which in turn drains the oceans of oxygen.
Scientists believe they've discovered a sixth mass extinction on Earth. Experts at China's Nanjing University, together with New York University's Department of Biology, believe a volcanic eruption devastated the planet during the Middle Permian period. This took place in south Asian, near Burma, some 260million years ago and potentially raises the total number of extinctions in the geologic record. Previously, historians believed there were five geological eras defined by extinction: the Ordovician, the Late Devonian, the Permian, the Triassic and the Cretaceous. Experts at China's Nanjing University, together with New York University's Department of Biology, believe a volcanic eruption devastated the planet during the Middle Permian period The first of these, around 540 million years ago, was probably the second most severe.