Birds: Birds are the only dinosaurs to survive the mass extinction event 65 million years ago. Frogs & Salamanders: These seemingly delicate amphibians survived the extinction that wiped out larger animals.
Tardigrades have been around a long time.
This means tardigrades have survived the planet's last five mass extinction events. They owe their longevity to some special characteristics.
As a group, sharks have been around for at least 420 million years, meaning they have survived four of the “big five” mass extinctions. That makes them older than humanity, older than Mount Everest, older than dinosaurs, older even than trees. It is possible that sharks just got lucky in the lottery of life.
The planet has experienced five previous mass extinction events, the last one occurring 65.5 million years ago which wiped out the dinosaurs from existence. Experts now believe we're in the midst of a sixth mass extinction.
How did sharks survive five mass extinction events? There is no single reason sharks survived all five major extinction events - all had different causes and different groups of sharks pulled through each one. One general theme, however, seems to be the survival of deep-water species and the dietary generalist.
"It's a great mystery," Elizabeth Sibert, a paleobiologist and oceanographer at Yale University, told Science News. "Sharks have been around for 400 million years. They've been through hell and back. And yet this event wiped out (up to) 90% of them."
Birds: Birds are the only dinosaurs to survive the mass extinction event 65 million years ago. Frogs & Salamanders: These seemingly delicate amphibians survived the extinction that wiped out larger animals. Lizards: These reptiles, distant relatives of dinosaurs, survived the extinction.
Endangered Species: Humans Might Have Faced Extinction 1 Million Years Ago. New genetic findings suggest that early humans living about one million years ago were extremely close to extinction.
Permian-triassic Extinction: 250 million years ago
The largest mass extinction event in Earth's history affected a range of species, including many vertebrates.
It's getting late. Scientists agree that the Earth is currently undergoing the sixth mass extinction in its 4.6-billion-year history.
There are two main reasons. First, crocodiles can live for a very long time without food. Second, they lived in places that were the least affected when the asteroid hit Earth.
Variables such as temperature, food sources, and oxygen levels are all factors that might impact dinosaur survival. Because dinosaurs lived in much warmer climates millions of years ago, many experts doubt they could even survive today.
Extinct Species: Pyrenean Ibex
The Pyrenean ibex is possibly the only extinct animal that has successfully been brought back to life — though it only lasted for a few minutes. The last of the animals died out in 2000, but three years later scientists used its frozen cells to clone a calf.
There are two basic types (genera) of shield shrimp, Triops and Lepidurus. Scientists credit Triops cancriformis as the oldest animal species. Other species may not be quite so old, but the natural histories of the species are similar.
Destruction of Habitat – It is currently the biggest cause of current extinctions. Deforestation has killed off more species than we can count. Whole ecosystems live in our forests.
Nicknamed the “Great Dying”, it is thought to have been triggered by catastrophic volcanic eruptions, resulting in dramatic environmental changes – including a runaway greenhouse effect and ocean acidification – that wiped out 95% of both land and ocean species.
Humans are causing the extinction crisis
Unsurprisingly, the continued warming of the planet, chiefly caused by humans burning fossil fuels, is the big, bad multiplier effect both directly threatening populations and making all the other threats worse.
More reproduction followed, and more mistakes, the process repeating over billions of generations. Finally, Homo sapiens appeared. But we aren't the end of that story. Evolution won't stop with us, and we might even be evolving faster than ever.
Broadly speaking, evolution simply means the gradual change in the genetics of a population over time. From that standpoint, human beings are constantly evolving and will continue to do so long as we continue to successfully reproduce.
They would not be able to fill all of those ecological niches that those dinosaurs once filled. They would still probably be small, scrawny, and very generalized. But instead, the mammals were able to evolve and diversify and, well, ultimately, millions of years later, become some humans.
After the asteroid struck Earth long ago, all birds with teeth went extinct. But many of the toothless ones kept living. Some scientists think not having teeth is what allowed these birds to survive. Fossils of early toothless birds show they were able to eat more plant-based food – specifically nuts, fruits and seeds.
The most severe extinction in the earth's history began 252 million years ago, wiping out 90 percent of ocean species and 70 percent of life on land. Modern sharks and their relatives were among the few that survived this "Great Dying," and new fossil finds hint as to how they may have clung on to life.