Which of the following is an example of evolution that can be studied firsthand by
scientists while it happens (meaning that scientists have opportunities to perform
experiments and to measure the outcome)?
A) The gradual decent of whales from tetrapod (four-legged) land mammal
ancestors
B) A dog shedding its thick winter fur so that it can stay cooler in the summer
C) The acclimation of a person's body to the low oxygen atmosphere at high
altitudes
D) The development of antibiotic resistance in bacteria