what cauases mass extinctions?

Answer 1

volcanoes (caldera volcanoes) which can cause nuclear winters where ash is trapped in the atmosphere and no sun light can reach the earth causing formation of the glaciers and temps cold enough to kill everyone, meteors, some earth quakes/ tech tonic plate movements have been linked to mass extinction, i imagine war could as well.... mass extinction could also be caused by a virus such that as the bird flu (which has yet to jump human to human but if it did would be more catastrophic than the plague (black death) in Europe that killed 2/3's of the population....

Answer 2

There's no single cause.

There have been several mass extinctions over the course of the Earth's history.

Probably one of the biggest occurred in the late Precambrian - when the most 'advanced' life on Earth was soft-bodied worms. Oscillations in global climate caused more than 90% of the Earth's surface to be coated in ice. There are glacial scrapings on stone laid down on the equator at the time.

Another mass extinction occurred at the end of the Ordovician about 450 million years ago. This one wiped many groups of marine invertebrates, including large numbers of brachiopods, bryozoans, trilobites and the majority of the reef-building species at the time. This one seems also to have been caused primarily by global cooling that created extensive ice sheets, lower ocean temperatures, and locking much of the ocean's water in the ice caps.

The Permian extinction may have been a combination of factors. In addition to global cooling again, the conglomeration of the continents into the supercontinent of Pangaea greatly reduced the amount of coastal habitat available around the world - devastating to the mostly marine ecosystems that still dominated the world at the time. There is also evidence of massive amounts of volcanic activity in Siberia at the time. There's some evidence that these volcanoes may have been caused by a massive impact (i.e. comet or meteor) slamming into the other side of the planet, or the volcanoes themselves could have caused a lot of destruction on their own.

The Cretaceous mass extinction that ended the dinosaurs is generally believed to be primarily caused by a massive extra-terrestrial impact.

The late Eocene mass extinction occurred as global temperatures soared. Marine temperatures were as much as 20 degrees C warmer than today - making reef building nearly impossible, and wiping out large numbers of marine species.

The late Pleistocene megafaunal extinction about 10,000 years ago may have been influenced by global climate change as the temperatures increased, but the primary cause in most areas seems to be closely linked to the first arrivals of humans in the region. Thus indicating that human hunting may have had a significant effect on these populations.

Answer 3

There are a lot of factors that can cause this, but the biggest is loss of food and climate changes. Whatever causes these to occur can cause mass extinctions.

Answer 4

environmental changes. These can be caused by dramatic events like meteor strikes, volcanos, earthquakes, and ice ages. Extinctions can also be caused by changes in weather patterns, introduction of new predators, evolution of new viruses or bacteria.

Answer 5

Well it all depends. For example when dinosaurs got extinct, it was because of the environment and the gases which killed them all. So because of that, other animals flourished.

Now what is causing extinction right now would be polar bears because of the environment which is killing one by one of them slowly and it isn't allowing them to reproduce much babies. So because of that there won't be enough polar bears until it causes a mass extinction.

Hope I explained that well.

=]

Answer 6

Disease, climate change, catastrophic events, or for religious people, drinking from God's cup of wrath.

Answer 7

mutated strains of infectious disease.. if no one has immunity to it, and there is no vaccine or treatment... infectious disease can kill MASSIVE amounts of people.
Case in point, the Bubonic Plague. Killed 1/3 of Europe!

Answer 8

armageddon