Natural selection may affect allele frequency in populations due to the fundamental forces of evolution except which of the following?
O gene drive
O gene flow
O genetic drift
O mutation

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.