Why do people have five toes on each foot?

skysmom65

Why Humans Have Toes: First, why do we have them? Although the earliest land animals had various numbers of toes (and/or fingers) those that had five fingers and toes won out in the struggle for existence. These pentadactyl (five toed) creatures established the ancestral (primitive) pattern for all land dwelling vertebrates. So the real question is not why do we have five toes, but why would we have less than five toes? In the evolutionary process the basic body plan does not change unless two things happen. First, a genetic trait has to appear (through mutation or through a novel recombination of established traits) that allows for the change. Therefore, all vertebrates will have five toes unless they possess a "gene" for fewer toes. Second, that gene must somehow confer an advantage on those who have it. Cursorial animals (runners) actual walk on the tips of their toes. It is advantageous for them because it increases their running leverage, and allows them to run faster. In other creatures, toes are part of a grasping foot, and that's where more recent human ancestry comes in. Humans are primates, a group of animals that was initially adapted to living in trees. When you are a tree dweller it is advantageous to have a grasping ability on all your limbs. This ability is a defining characteristic of the primate group. When human ancestors left the trees they became more adapted to running on the ground. Part of this adaptation expressed itself through shorter toes. This adaptation was advantageous because running on the ground was more important to the early human lifestyle than was climbing in the trees (a lot of scientific debate now centers on how "tree adapted" or "ground adapted" early human ancestors actually were). Our body design is determined by our evolutionary ancestry. We have toes because our ancestors had toes. MORE: http://www.answers.com/topic/why-do-humans-have-toes Mar 07 07, 10:46 AM