Over many generations and an extended period of time the genetic change of an organism is bound to happen, these changes are called biological evolution. Scientists have studied these changes and how they occur for many years, all starting with Charles Darwin on the Galapagos Islands. …show more content…
It is only a mechanism that, according to Darwin, can lead to evolution. As Peter and Rosemary put it, natural selection takes place within a generation, but evolution takes place across generations.” (Weiner 79). This description follows the definition given earlier, that evolution takes place across multiple generations and an extended period of time, meanwhile natural selection is only between one generation to the next. The book gives us an example of how the natural selection that took place lead to the evolution of the finches beaks. “In the drought of 1977 the Finch Unit had seen natural selection in action. Now in its aftermath they saw evolution in action, in the dimensions of the birds’ beaks and in many other dimensions too.” (Weiner 81). With that said it shows how the finches beaks and the finches themselves were changed from the drought. In the book Weiner says, “So the birds were not simply magnified by the drought: they were reformed and revised. They were changed by their dead. Their beaks were carved by their losses.” (Weiner 82). This shows why natural selection and, in some cases, evolution is good and …show more content…
An example can be seen with John Endler and his guppies, “What the Grants are to Darwin’s finches, Endler is to guppies.” (Weiner 89). Endler studies guppies from small streams in northeastern South America. His guppies each have unique spots on them just like beak variations in Darwin’s finches. The guppies spots are heritable and “...each guppy inherits its particular palette of colors, and also the general size and brightness of ensemble, from its parents.” (Weiner 89). Natural selection can be seen with Endlers guppies by their need for camouflage from predators. The better the camouflage and more gaudier the guppy looks than it’s more likely to survive and mate with a female and pass on the better enhanced