What is most likely to cause a mass extinction?

Answer 1

In order to cause a mass extinction, something has to happen with worldwide (or nearly so) effects. In at least two of the mass extinction events for which we've determined a likely cause, the cause was an astrobleme; an impact of a comet, asteroid or other celestial body with the Earth.

In at least one other, the cause appears to have been massive volcanic eruptions, but after that long, we cannot yet determine the cause of the volcanism.

Answer 2

Mass extinctions could be caused by giant meteors colliding with the Earth. They could also be caused by the Earth tipping off its axis. Global warming or global cooling will affect many colder climate animals which would cause them to die out.

Answer 3

There are many causes for mass extinctions. Climate change, meteorite/comet impact & species domination are a just a few reasons.

Modern Mass Extinction (2 Ma to now)

Many scientist argue that we are currently in a mass extinction even. Wild changes in the environment since the start of the ice age have been causing havoc with life on Earth. This accelerated when modern man started to become the dominant species. Loss in habitats, hunting and environmental changes caused by human activity has caused many species to become extinct. If current theories are correct many more species will soon become extinct without mans direct intervention (there are more tigers in private hands in the USA than the total number in the wild).

Cretaceous Extinction. (65 Ma)

Most common theories suggest there was not one but two causes for the cretaceous extinction event. The end of the cretaceous shows a marked increase in volcanic activity on Earth. Huge eruptions now known as the Deccan Traps in India released huge amounts of sulphurous gases and also CO2 into the atmosphere. Earth was already a dieing world. The final nail in the coffin was caused the impact of a meteorite in Yucatan in modern day Mexico. Estimates suggest that 18% of land vertebrate families and 16% of marine animal families, 47% of all marine genera became extinct.

End Triassic Extinction. (214 - 199 Ma)

This extinction we believe was caused by huge volcanic events. This was the time in history that the Atlantic Ocean first started to open. Huge outpouring of magma and associated volcanic gases in the "Central Atlantic Magmatic Provence" and the shifting continents caused wide scale environmental damage. About 22% of all marine families died, 52% of all marine genera became extinct. This also caused the end of the dominance of the mammal like reptiles, the synapsids. Only very small species managed to survive and would soon evolve into the 1st true mammals.

Permian-Triassic Extinction. (251 Ma)

Less is known of this event. Scientist suggest that there was a large impact event although there has not been much direct evidence found. Another theory is a huge volcanic event from the Siberian Traps. This caused a reduction in the amount of oxygen in the oceans. The event caused the extinction of about 53% of all the Marine families, 84% of all marine genera and about 60% of all the land species.

Late Devonian Extinction (364Ma)

Less is known about the causes of this event. Some scientist suggest that this was in fact 6 separate events spread over 25 million years. The most probable cause was changes in the environment. Little is known about land animals at the time but it is clear that 22% of marine families, 57% of marine genera died out.

Ordovician-Silurian Extinction (450 - 440 Ma)

Caused by massive changes to the environment. Glaciation due to an ice age caused changes to ocean levels and currents. A further wave of extinction marked the end of the cold period. Estimates that 25% of marine families, 60% of marine genera became extinct.

Answer 4

Any event that significantly changes the environment of a particular species can cause them to become endangered or even to become extinct. If the temperature of the earth's atmosphere were to increase as little as 3 degrees on average, it would cause major changes in the trade winds which many bird species use for migration, which theoretically could cause their pattern to change resulting in reduced numbers. The food chain from single cells organisms living in the sea up to the to the "top" of the food chain - man, would be impacted as well. Think of the picture of the smallest fish being eaten by a larger fish being eaten by a still larger fish and so on. If the smallest fish dies, the next bigger fish has no food supply and so on up the food chain until the diet is diversified enough to be replaced.

Answer 5

There are many causes that could cause a mass extinction. The one that wiped out the dinosaurs was an asteroid. The cause of the Permian extinction was probably a Gamma Ray that hit the Earth. Volcanoes, Destruction of habitat, a more successful species, or not enough food or water are some more possible causes of a mass extinction.

Answer 6

every period of time like two hundred sixty million years (i don't know the exact) a planet (or whatever in the universe) somewhat related to the sun will orbit really close to earth as if the collapse. it may fill the atmosphere with dust to block the sunlight, so that is probably how the dinosaurs became extinct.

Answer 7

how might the impact have led to the mass extinction

Answer 8

Volcanism, asteroid bombardment, radiation from space, climate change from various causes, disease, and (future) nuclear war.

Answer 9

When many types of organisms become extinct at the same time, a mass extinction has occurred.

Answer 10

frequent volcanic eruptions~apex