Question

ending and starting eras and period

• pattern of extinctions followed by adaptive radiation is seen in the fossil record
• punctuated equilibrium : periodic bursts of species change as a result of sudden environmental change
• why are there no penguins at the north pole, and no polar bears at the south pole?
• distribution of organisms reflects their evolutionary history

value: 7
_____ caused the mass extinction 65 mya.
○ a. a volcanic eruption
○ b. an asteroid striking the earth
○ c. a black hole next to the sun
○ d. an airborne viruses
○ e. an antibiotic resistant bacteria

Explanation:

The mass extinction 65 million years ago (mya) is widely attributed to an asteroid striking the Earth. This event, known as the Cretaceous - Paleogene (K - Pg) extinction event, had a profound impact on the Earth's ecosystems. The asteroid impact would have caused immediate devastation through shockwaves, fires, and the ejection of debris into the atmosphere. The debris would have blocked sunlight, leading to a global cooling effect, disrupting photosynthesis, and causing a collapse of food chains. Volcanic eruptions (option a) can cause significant environmental changes, but the evidence strongly points to the asteroid impact as the main cause of the 65 mya mass extinction. A black hole next to the sun (option c) is not a scientifically supported cause for this extinction event. Airborne viruses (option d) and antibiotic - resistant bacteria (option e) are not relevant to the large - scale mass extinction that occurred 65 mya.

Answer:

B. An asteroid striking the earth