Microevolution refers to changes that occur within a single species or group or organisms. Microevolution, as opposed to macroevolution, occurs in a short period of time. In microevolution, the ancestor and the descendant obviously belong to the same type. For example, certain pests have evolved in such a way that they become immune to pesticides; the same thing has happened to certain weeds and herbicides. Hope this helps.
Smooth muscles depolarize as a result of a transmembrane current of Calcium ions. When an action potential depolarizes the muscle cell membrane, it also travels into the body of the cell via the t-tubules. Unlike skeletal muscle, smooth muscle is dependent in two sources of calcium in order to intiate contraction. These two sources are calcium sequestered in the S.R. of the smooth muscle cell.
The answer to your question is B- introduction of non-native animal species
A
it says the swallows had Continued reduced reproductive success over time.
