Evolution: The beneficiaries of mass extinction

October 10, 2017

Mass extinctions were followed by periods of low diversity in which certain new species dominated wide regions of the supercontinent Pangaea, reports a new study.

The findings, published in Nature Communications, indicate that mass extinctions may have predictable consequences and provide insights into how biological communities may be expected to change in the future as a result of current high extinction rates.

Mass extinctions are thought to produce 'disaster faunas', communities dominated by a small number of widespread species. However, studies to test this theory have been rare and limited in scope, such as being focused on small regions.

The researchers, from the University of Birmingham (UK), North Carolina State University (USA), University of Leeds (UK) and CONICET?Museo Argentino de Ciencias Naturales (Argentina) assessed long-term changes in biodiversity in the supercontinent Pangaea. They analysed changes in nearly 900 animal species between approximately 260 million and 175 million years ago (spanning the late Permian to Early Jurassic). This period witnessed two mass extinctions and the origins of dinosaurs and many modern vertebrate groups.

These extinction events were very important in shaping the evolutionary history of life. The end-Permian event wiped out many of the groups which dominated life on land at the time. By doing so, it freed up ecological niches and allowed new groups to evolve, including the earliest dinosaurs, crocodiles and relatives of mammals and lizards. The end-Triassic event then again wiped-out many major groups, helping to set the stage for the dinosaurs to take over.

The team compared the similarity of animal communities from different regions of the globe based both on which species they shared, and how closely related the species from one region were to those from other regions. This allowed them to calculate the overall similarity of faunas from across the globe through time - the "Biogeographic connectedness".

David Button, a postdoctoral researcher at North Carolina State University and the resident Brimley Scholar at the NC museum of Natural Sciences said, "These results show that, after both mass extinctions, biological communities not only lost a large number of species, but also became dominated by widespread, newly-evolving species, leading to low diversity across the globe. These common patterns suggest that mass extinctions have predictable influences on animal distributions and may have the potential to guide modern conservation efforts."

Richard Butler, Professor of Palaeobiology at the University of Birmingham, said, "Mass extinctions were global disasters that fundamentally reshaped ecosystems. Our new analyses provide crucial data that show just how profoundly these cataclysmic events changed and influenced animal distribution.

Martín Ezcurra, Researcher of the Museo Argentino de Ciencias Naturales, said, "The fossil record has the potential to test evolutionary hypotheses in long time spans, which is not possible if evolutionary researches all limited to living plant and animals. This study allows understanding better how macroevolutionary patters developed in the deep time and may help to predict large-scale ecological changes in the short term".

Due to human activity, we are currently in the sixth mass extinction. There are already concerns that humans are driving global faunas to become more homogenous as a result of landscape simplification, increasing temperatures and introduction of exotic species. This study identifies an additional contributor to this risk, as ongoing biodiversity loss will be expected to result in a "disaster fauna" of more similar species across the globe.

University of Birmingham

Related Dinosaurs Articles from Brightsurf:

Baby dinosaurs were 'little adults'
Paleontologists at the University of Bonn (Germany) have described for the first time an almost complete skeleton of a juvenile Plateosaurus and discovered that it looked very similar to its parents even at a young age.

Bat-winged dinosaurs that could glide
Despite having bat-like wings, two small dinosaurs, Yi and Ambopteryx, struggled to fly, only managing to glide clumsily between the trees where they lived, according to a new study led by an international team of researchers, including McGill University Professor Hans Larsson.

Some dinosaurs could fly before they were birds
New research using the most comprehensive study of feathered dinosaurs and early birds has revised the evolutionary relationships of dinosaurs at the origin of birds.

Tracking Australia's gigantic carnivorous dinosaurs
North America had the T. rex, South America had the Giganotosaurus and Africa the Spinosaurus - now evidence shows Australia had gigantic predatory dinosaurs.

Ancient crocodiles walked on two legs like dinosaurs
An international research team has been stunned to discover that some species of ancient crocodiles walked on their two hind legs like dinosaurs and measured over three metres in length.

Finding a genus home for Alaska's dinosaurs
A re-analysis of dinosaur skulls from northern Alaska suggests they belong to a genus Edmontosaurus, and not to the genus recently proposed by scientists in 2015.

Can we really tell male and female dinosaurs apart?
Scientists worldwide have long debated our ability to identify male and female dinosaurs.

In death of dinosaurs, it was all about the asteroid -- not volcanoes
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers.

Discriminating diets of meat-eating dinosaurs
A big problem with dinosaurs is that there seem to be too many meat-eaters.

Jurassic dinosaurs trotted between Africa and Europe
Dinosaur footprints found in several European countries, very similar to others in Morocco, suggest that they could have been dispersed between the two continents by land masses separated by a shallow sea more than 145 million years ago.

Read More: Dinosaurs News and Dinosaurs Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.