The answer is reproductive isolation. Reproductive isolation ensures members of different species do not produce offspring. In this case, geographical separation is ensuring that individuals from the two different populations are not able to mate with each other. Eventually, through different selective pressures, the two populations will diverge sufficiently in genotype to become distinctly different.
Answer: C
Explanation: The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days.
Coal
Coal is a combustible black rock that is formed from prehistoric plant remains. Coal is formed from the anaerobic decomposition of dead plant matter such as trees, ferns, mosses and other marsh plants that grew on the earth surface over millions of years ago. Coal is composed largely of carbon and is usually burned as a fuel.
