The next Great Dying is coming. In fact, it's definitely already here.
The last time our planet saw a dying-off of global proportions was approximately 250 million years ago, and most of the life on Earth was wiped out for good. Plants, land and marine vertebrates, and invertebrates were all devastated. Scientists call this incident the Permian-Triassic extinction event.
Right now, we're witnessing the sixth mass extinction that Earth has ever known. But this time, it's not the devastating impact of an asteroid, violent volcanism, or the deep-freeze of an ice-age that's purging the planet of its life forms. It's us.
So what is any intelligent, enterprising animal to do when faced with the potential demise of its own species and most of those around it? Prepare.
A new study published in Scientific Reports may help us to predict how the further deterioration of environments and natural resources, due to the effects of climate change, will physiologically impact modern species, possibly even humans.
When a series of eruptions out of several Siberian volcanos kicked off the Permian-Triassic extinction event, giant plumes of noxious carbon were released into the atmosphere, altering Earth's climate and extinguishing most life on it.
However, one genus survived the extinction event and continued to thrive long after. A team of international paleontologists recently took a closer look at fossil evidence of the growth patterns of this ancient mammal-like reptile, Lystrosaurus (elegantly known as "shovel lizard"), before and after the extinction boundary. What they discovered in fossil records, according to the study, was that Lystrosaurus exhibited two clever adaptations for survival in its newly inhospitable surroundings: living faster, and dying younger.
"Before the Permo-Triassic extinction, the famous therapsid Lystrosaurus had a lifespan of about 13 or 14 years based on the record of growth preserved in their bones," co-author Ken Angielczyk, a paleontologist at the Field Museum, said in a statement. "Yet, nearly all of the Lystrosaurus specimens we find from after the extinction are only 2-3 years old. This implies that they must have been breeding when they were still [relatively young] themselves."
The decreased lifespan of Lystrosaurus also came with some physical changes, the authors noted. Because the ancient creature was only living about a quarter as long as it did before the extinction event, it became much smaller and less heavy—think pygmy hippo-sized to large dog-sized—but much more prolific. Lystrosaurus started to breed at a younger age, according to ecological simulations, and by doing so increased its chance of survival by 40 percent.
Scientists don't have to extrapolate much to apply this adaptation scenario to modern animals. Atlantic cod, the study notes, are already dramatically decreasing in size and are breeding as early as possible, due to commercial fishing which has removed much of the larger cod from wild populations.
African monitor lizards, which are currently being over-hunted and exploited for the skin and pet trade, are displaying similar shifts.
"With the world currently facing its sixth mass extinction, paleontological research helps us understand the world around us today," said Angielczyk in a statement. "By studying how animals like Lystrosaurus adapted in the face of disaster, we can better predict how looming environmental changes may affect modern species."
But as extinction timelines reveal, not all species are as resilient as Lystrosaurus. At least 10,000 species disappear forever each year, according to the World Wildlife Fund, which is somewhere between 1,000 and 10,000 times higher than natural extinction rates.
Whether or not this modern epoch will have its winners and losers is yet to be seen. But for now, my money's on the little guys.