What is the mechanism of evolution proposed by darwin?

How are the tortoises that darwin observed on the galápagos islands similar to the anoles that losos studied

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this