IC challenge: Evolve a bicycle into a motorcycle!

You're correct, NS cannot be totally isolated from randomness, and no one is claiming it is. For example, the baddest, meanest Tyrannosaurus Rex that ever lived might have been killed when an earthquake brought a cliff face down upon it, a completely random event, at least from a biological perspective. This Tyrannosaurus may have been ideally suited to dominate his environmental niche and should have had the opportunity to pass on its genes by mating many times, but its life was unfortunately prematurely snuffed out by a random event.But for the most part NS means competing with others, both of your own and other species, for access to resources such as food and mates. Those with characteristics enabling them to better compete are more likely to pass those characteristics on to succeeding generations. While randomness is not excluded from the process, randomness is not a significant component.The component of evolution that has a much larger component of randomness is mutation. Which mutations happen in a population is largely random, and the degree of advantage/disadvantage they confer is also largely random.The process of random mutation and natural selection is illustrated by bacterial experiments. Growing a population of bacteria on a substrate containing some hostile substance (within reason - sulfuric acid would not be good choice) will breed a population of resistant bacteria through a process of random mutation and natural selection. The mutations occur randomly, and some by chance will confer an advantage that allows the bacteria to continue growing and reproducing in the presence of the hostile substance. The DNA of the final bacterial population can be analyzed to reveal the nature of the genetic changes (random mutations) that conferred the advantage.--Percy