Male-Male Competition

In some species, males engage in complex competitive behaviors, which in many cases necessitate growth of elaborate ornamental horns. Although such competitions are rarely fatal, injuries and death can occur. What is the evolutionary advantage for a species to have potentially-lethal fighting among its members, not to mention spending so many calories growing awkward horns? Simply this: because females must expend a tremendous amount of energy and time in bearing and raising young, any selection among males that helps eliminate weaker, less-fit potential mates ensures a better genetic pool for the species.