Question: how do limbs develop and evolve

Stuart Mourton answered on 21 Jun 2011:

Like all evolution, limb development is due to genetic changes being retained in a species as they provide useful changes to the animals in question. For example a monkey that had a gentic mutation that meant it’s arms were longer may have found it easier to get food. This monkey would then become stronger, and have more chance of becoming the dominant male in the group and mating with the females. This genetic muatation would then be passed onto all his offspring and over a long period of time, the gentic change would be present in all the animals from that group. this would slowly then be passed between groups and over hundreds of thousands of years, this trate would become the norm for the whole species.