Answer:
1) When African climates were wetter millions of years ago, there were more trees and our earliest ancestors got around by climbing in them. Scientists think that when African climate dried and the number trees was reduced, our ancestors had to move in a new way – by walking on two legs through grasslands.
2) Glacial melting has increased since the 1980s, and popular reports often suggest there will be significant impacts on local populations, including migration. Even so, glacial retreat has not triggered new migration flows and has had a limited impact on the existing migratory patterns.
Explanation:
