In my opinion, the correct answer among the choice given above is option D. It is advantageous for grazing mammals to gather in groups because groups <span>offer greater protection from predation. It protects them because predators will think twice in nearing the group because it is outnumbered.</span>
Climate changes thats what im guessing .. not too sure though ... sorry
2, because a theory is not a law that can not be changed, and new evidence can change a theory.
The flooding of half part of the forest have successful separate the population of frogs in that ecosystem into two different set of frogs. This is an example of allopatric speciation, that is, the population become separated as a result of geographical barrier. This separation will make the two set of frog population to become new species. On the long run, the two species may become unable to relate sexually.