Various and sometimes peculiar characteristics have evolved as a result of a need to survive and a desire to reproduce. Male traits, as a result of male competition over mates, seem to have become exaggerated. Two evolutionary biologists debate the primary function of antlers in caribou, a close relative to deer.
Biologist 1
The driving force behind survival is the desire to reproduce. This desire ensures the survival of a species. Male caribou, as most male mammals, are driven to mate with as many females as possible, in order to maximize their hereditary fitness, the genes they successfully pass on to offspring. Because of this reproductive strategy, males will compete, fighting sometimes to the death over a female. Antlers are merely a weapon that caribou have evolved to better compete. Larger males have larger antlers, and often dominate the reproductive field.
Biologist 2
While caribou males do indeed compete for female access, female choice is the driving force behind the mating strategies. Females select the males with which to reproduce, and competing is merely a display that aides the females in their selection process. Antlers are probably a fairly good indicator of a male’s general health: big antlers indicate a healthy male. Therefore, males with bigger antlers will have access to more mates, simply because more females will choose to mate with these males. Using antlers for defense and competition is only a secondary use.