Answered

what is a mass extinction? ​

Sagot :

Driel20viz

Answer:

A mass extinction event is when species vanish much faster than they are replaced. This is usually defined as about 75% of the world's species being lost in a 'short' amount of geological time

Explanation:

Joshuamagsayo19viz

A mass extinction is usually

defined as a loss of about

three quarters of all species in

existence across the entire earth

over a "short" geological period

of time.

Given the vast amount of time

since life first evolved on the planet, "short" is defined as anything less than 2.8 million years.

Mass extinctions usually associated with organisms that are macroscopic rather than microscopic. Example of mass extinctions are Permian extinction of marine species, and Cretaceous extinction of various species, including dinosaurs.

The cause of mass extinctions happen because of climate change, asteroid impacts, massive volcanic eruptions or a combination of massive volcanic eruptions (the deccan traps) and the fall of a big meteorite.

there are top five extinction:

  • Devonian extinction: 365 million years ago
  • Permian-triassic extinction: 250 million years ago
  • Triassic-jurassic extinction: 210 million years ago
  • Ordovician-silurian extinction: 440 million years ago
  • Cretaceous-tertiary extinction: 65 million years ago

An extension event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on earth. Such an event is identified by a Sharp change in the diversity and abundance of multicellular organisms. Extinction occurs at an uneven rate.