Answer: Natural selection is one of the forces of evolution and the enviroment where the species lives is the selection agent. For example, suppose a mosquitoes population in a environment free from insecticides, in this environment there's a high frequency of non-resistant mosquitoes because the environment is not exerting any pressure on the resistence trait. But when the environment changes and we use a insecticide upon the mosquitoes population, the populations changes because the non-resistant ones die but those resistant survive and beggin to reproduce more effectively. That's natural selection, differences in survival and reproduction between individuals with different phenotypes (traits) and this differences depend of environmental changes.
Answer:
More recent phylogenetic analyses, based on mitochondrial DNA, have suggested that the crocodile shark is closely related to either the megamouth shark or the sand sharks (Odontaspididae).
The first cycle hope this helps
The correct answer is B. Tundra
Tundras are the coldest places in the world and are located far north, around the arctic circle, and incorporates countries such as Finland, Russia, Alaska, and others.