Humans (Us). We are the cause of biological extinctions. We use Natural Resources exponentially. As mankind population increases the greater the chance of an increase percentage of a species extinction. All natural life is a cycle, once we disregard its benefits to us and overuse its properties we may find ourselves begging for just the basic mother nature has to offer us.
Hunting was a major cause of extinction in the United States in the 19th century. Men would hunt the animals for their meats, skins, and fur.
Persistent and widespread over hunting was the principle cause of their demise.
the sun blowing up in the next 10 years
Their bodies aren't adapted to the new environment yet.
They are the end-Ordovician extinction, end-Devonian extinction, end-Permian extinction, the Triassic extinction, end-Cretaceous extinction.
"Currently, nobody is quite sure what causes MDD. One hypothesis is that it is biological -- the brain structures of people with MDD are different than those without. Drug and alcohol use is also known to cause MDD."
The dingo is believed to have been a major cause of the extinction of both the Tasmanian devil and the Thylacine from the Australian mainland.
Anthrax can be used as a biological weapon as only 100gms. of Anthrax released over a major city may cause up to 3 million casualties.
There were five major extinction events in the past. They are called the Cretaceous-Tertiary (or K-T) extinction event, the late Devonian mass extinction, the Permian mass extinction, the Ordovician-Silurian mass extinction and the Triassic-Jurassic mass extinction event.
Early humans hunted mammoths and are thought to have been a major cause of their extinction although there is no definitive proof.
Meteor, extinction, atmosphere, death. There's a lot more... too many to name.
A major extinction event.