On Evolution !
I was just watching a series of lectures on Khan's Academy on Evolution. From the very start I had somehow believed that evolution is a continuous process whereby the entire generation of a specie undergoes small incremental modifications in traits in order to be able to adapt to the environment better. However Khan explains evolution as "survival of the fittest" which leads to more reproduction of the genetic makeup of the particular specie which has a genetic edge in terms of survival. So, if humans needed to stand upright inorder to survive, then amongst apes, due to natural variation that is present in all members of a specie, there would be an ape which due to its genetic makeup was able to survive in a slightly better way as compared to the rest of the apes. Over many generations, this ape's posterity would be growing at a faster rate as compared to the offsprings of the other apes and eventually there would be a time when these apes who stand slightly up...