Question

what is mass extinction
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Answer 1

Explanation:

An extinction-level 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. It occurs when the rate of extinction increases with respect to the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from the threshold chosen for describing an extinction event as "major", and the data chosen to measure past diversity.

Answer 2

Answer:

• 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.
• Mass extinctions happen because of climate change, asteroid impacts, massive volcanic eruptions or a combination of these causes
• One famous mass extinction event is the one that lead to the extinction of dinosaurs, 65 million years ago.

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