We know that there must be individuals of two sexes for successful reproduction. However, this is by no means a universal rule. So why did nature create sexual reproduction? Reproduction in nature is associated with mating of individuals of two sexes. Mammals, birds, reptiles, fish, insects, and spiders have males that fertilize females of the […]

Were Charles Darwin and Ernst Mayr correct? A recent study of a diverse lizard genus suggests they were. Charles Darwin first wrote that geographic isolation is an essential precondition of natural selection; he exemplified the pattern with famous Galapagos finches. He supposed that the one finch species had once expanded through the islands of the […]