As animal weaponry improves, its lethality declines. Seems a bit paradoxical.

Be sure to check out the NY Times up close slide show of beetle weaponry.

Dr. Emlen noticed a tendency for weapons to start out small, like mere bumps of bone, and then to evolve to more ornate form. The small weapons are actually quite destructive since their only role is to attack other males. But the more baroque weapons, even though they look more fearsome, seem to cause lesser loss of life.

The reason is that the more menacing weapons have often acquired a signaling role. Instead of risking their lives in mortal combat, males can assess each other's strengths by sizing up a rival's weapons, and decline combat if they seem outclassed. The ornate weapons also lend themselves to ritualized combat in which males may lock horns and assess each other's strength without wounding each other.