AP BIOLOGY

Detailed explanation-1: -The most recent work on the K-T extinction has centered on two hypotheses that suggest a violent end to the Cretaceous: a large asteroid impact and a giant volcanic eruption.

Detailed explanation-2: -Punctuated equilibrium occurs because genetic variations are passed down quicker, thus increasing the rate of evolution, and speciation. Tyrannosaurid fossils and Mollusks in the Turkana Basin are examples of punctuated equilibrium.

Detailed explanation-3: -KT extinction stands for Cretaceous-Tertiary Extinction. This is a global extinction event that witnessed the elimination of about 70% of the species living on the earth within a very short time 65 million years ago. This mass extinction is known as KT extinction.

Detailed explanation-4: -This theory states that a bolide (meteorite or comet) impact may have triggered the extinction event by ejecting a huge quantity of rock debris into the atmosphere, enshrouding Earth in darkness for several months or longer.