In comparing nucleotide or amino acid sequences, researchers base evolutionary relationships on the assumption that

Which term describes the number of waves that pass a given point in a given time? crest frequency trough wavelength

Environmental impacts on evolution : mastery test

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