280 million years ago, there was a vast supercontinent called Pangaea. The landmass was so large, clouds disappeared before reaching its center, creating a desert three times as large as the Sahara. Finbacked reptiles, the ancestors of the dinosaurs, lived on this land, and jawless fish and trilobites inhabited the waters.
This land was a little warmer than it is today, and oxygen was more abundant. This age was known as the Carboniferous.
Over the years, Carboniferous turned into Permian. The Finbacks got larger and larger. Trees evolved. When you could be tempted to think that this golden age could go on forever, disaster struck. Major volcanic activity began in what is now Siberia. Carbon dioxide poured into the air from volcanoes, causing global warming in an already overheated planet. Soon the clouds of noxious gas blocked out the sun, causing global cooling. The activity released clouds of methane. The temperature soared.
Most of the species could not handle this climate change. Nineteen out of every twenty species were wiped out. Pretty much only the reptiles survived. With no competition, they evolved into the Dinosaurs.
So, what is an endangered species? Good question. If a species is endangered, this means the species is in danger of becoming extinct unless somebody does something about it. The humpback whale population is rising rapidly, even though it is still on the endangered species list. The humpback whale should be taken off the endangered species list, even though it should still be protected carefully.
Before about 1950, people did not care a species was endangered or not. The Thylacine went extinct almost unnoticed in 1936. People are caring more about endangered species in the present, but there is still a danger of an extinction unless people put more effort into the conservation of species.
What defines a mass extinction? A mass extinction is when over 40% of all the known species on earth go extinct. The first mass extinction was in the Ordovician when the first plants appeared. The plants sucked up much of the carbon dioxide in the atmosphere. This caused global cooling.
There is a low chance that we will cause a mass extinction, but humans have already endangered many species. If we sit in our homes doing nothing, the koala, panda, lion, sea turtle, and many, many other species will become extinct. The good thing is, you only have to make a small donation. If every person in a developed country donated ten cents for pandas, the panda might be taken off the endangered species list within fifty years! However, we have a long way to go, and this is only the beginning ...