AP BIOLOGY

Detailed explanation-1: -In this way, mass extinction prunes whole branches off the tree of life. But mass extinction can also play a creative role in evolution, stimulating the growth of other branches. The sudden disappearance of plants and animals that occupy a specific habitat creates new opportunities for surviving species.

Detailed explanation-2: -Negative rates of diversification in plants (meaning that more species died out than new species were formed) were never sustained through long time periods. This indicates that, in general, plants have been particularly good at surviving and recovering through tough periods.

Detailed explanation-3: -Mass extinctions affect the history of life by decimating existing diversity and ecological structure and creating new evolutionary and ecological pathways. Both the loss of diversity during these events and the rebound in diversity following extinction had a profound effect on Phanerozoic evolutionary trends.

Detailed explanation-4: -The correct answer is a). Mass extinctions result in the loss of many species due to either a single catastrophic event or several issues that work together to provide hazzards for many species.