Once upon a fourth dimension , there was a supercontinent list Gondwana . Around 85 million years ago , during itsfragmentation , the res publica we now know as Australia began to form – and around 30 - 35 million age ago , itssegregationfrom Antarctica was complete .
As revealed in a new study by the Australian National University , it appears that this tectonic fault coincided with mass extinction on the brand unexampled continent , pass over out a decent swath of the country ’s lizards .
write in the journalEvolution , the squad excuse how they took a comprehensive look at the evolutionary history of the Pygopodoidea , a superfamily of ecologically various lizards that have long occupied various niche across Australia .
Using molecular genetics , fossil grounds , and complex algorithmic rule to prefigure how these geckos would have responded to the sudden isolation of Australia , they get to the last that their diversity bottom - out around that time .
trap down the causes of such enormous extinction events are always quite tricky , and there’srarely just one main adversary . The non - avian dinosaur ’ last chapter may have been grade by a catastrophic asteroid impact , but the salary increase of opportunistic mammalian and prolonged volcanism also played key roles long before the putsch de grace took stead .
In this font , however , it appears that there was indeed one villainous phenomenon above all others – rapid mood change . In this casing , over 100,000 year , the region chill by 5 ° C ( 9 ° degree Fahrenheit ) – super quickly by any measure – and Australia began to transition from being a tropical rain forest - covered land mass to a cold , arid one .
To be fair , the entire reality at the conclusion of the Eocene Period ( around 33 million years ago ) was cool down , and no one is entirely sure why . Preserved clime record paint a picture that there was a rather significant drawdown in the amount of carbon dioxide in the ambiance , and some have suspected this was related to several as - of - yet unconfirmedasteroid impactsaround the existence .
Whatever the crusade , Earth in general became decided chilly , and around 12 percent of all nautical life decease out – a huge experimental extinction event to be certain , but nothing like that which finished off the non - avian dinosaur , or theGreat Dyingevent 252 million years ago that wiped out up to 96 per centum of all life .
Australia ai n’t what it used to be . FiledIMAGE / Shutterstock
In any display case , the isolation of Australia appears to have left these geckos strand on a continent they could n’t endure in . With their traditional environments disappearing all over the continent , mass of them were ineffectual to adjust and die out .
Those stealthy few that did manage to adapt last on to busy the eventual hot deserts of Australia , and ultimately evolved into the ten thousand of species you may still see there today . Many died , and some flourish – the history of natural selection in a nutshell , really .
