alive. In order for this theory to remain true, there should be length increases in limbs in the same proportion as to the increases in their heads and necks. On the other hand, the proposed theory deals with the notion that the length of the giraffe neck increased because the neck is used as a weapon during intrasexual combat (Simmons 773). The basic idea of this is that during competition two males stand next to each other and exchange hits by using their necks. The top or back of the skull is actually used to knock the competitor to the ground. It is likely that with a larger neck and head, the giraffe is more destructive. It is also assumed that larger and longer necks would be selected for. The process of necking is unique to giraffes and only male giraffes have ever been viewed doing this. Therefore, it is likely that this action is related to sexual selection. Necking has been observed to be very effective for giraffes to obtain their mates. Often the males are knocked unconscious or even killed during the fighting. The violent nature of these fights is unbelievable. Even when an opponent may be knocked to the ground, that does not stop the fight. They may still be kicked or stepped which can eventually lead to death. "Sexual selection is a special form of natural selection that is responsible for the evolution of traits that promote success in competition for mates" (Kodric-Brown 309). There are two different forms of sexual selection: it can be involved with the evolution of traits or it can be related to the evolution of characteristics which would make the male look more appealing. Intrasexual competition is involved more with the evolving traits which than can be used as weapons when fighting each other for the right to mate with the female. One general feature of sexually selected traits is that the trait is often more costly for the individual to produce. This holds true for giraffes. Since their necks and...
