Anthro2050 1st Edition Lecture 4 Outline of Last Lecture I Evolutionary Theory II Important Figures in Evolutionary Theory Outline of Current Lecture III Charles Darwin IV Natural Selection and Adaptation Current Lecture Charles Darwin Heavily influenced by Malthus Lamark and Lyell Born in 1809 to a fairly wealthy family Was interested in natural sciences from an early age His father wanted him to be a doctor and sent him to medical school While Darwin found that he did not like studying medicine and was horrified by surgery however this was where he was first introduced to the evolutionary theory of the time He then went on to major in the natural scientists At 22 Darwin gained an opportunity to sail the world on the HMS Beagle as part of a five year natural science survey While traveling he made many observations of natural life The area most commonly related to his studies are the Galapagos Islands There he noticed that different types of similar animals on different islands seemed to have changed over time to suit the conditions of each island for example the differences in the tortoises on the islands He went back home and married and had a family Due to health issues he was kept at home mostly where he dwelled on his observations from the trip and later formed his theory of evolution by natural selection While he formed his theory in 1839 he procrastinated on publishing it for the next two decades He knew his ideas would be controversial and difficult to present to both the scientific community of the time and the general public However after receiving a letter from a colleague Alfred Wallace that Wallace had written while in a malaria induced hallucination These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute The letter had ideas that were the same as Darwin s ideas on natural selection He knew that if he didn t publish soon Wallace would Originally Darwin and Wallace were to publish and release the theory of natural selection together however since Darwin was already well established in the scientific community he ended up getting full credit Darwin published the Origin of Species in 1859 Natural Selection and Adaptation There are four main principles that sum up Darwin s theory of natural selection 1 In each generation there are more offspring produced than can survive 2 Offspring vary though not all the same they do resemble their parents and siblings 3 Some of these variations are better suited for survival than others 4 The competition for resources favors individuals with these variations resulting in that individual s survival The term fit in the popular phrase survival of the fittest has nothing to do with bigger better stronger faster Fit in Darwinian terms refers to an individual s ability to live to reproductive age find a mate and reproduce successfully Adaption the functional response of populations to the environment that result from natural selection A feature produced by natural selection in a population these changes occur and develop over many many generations In order for a feature to be considered an adaptation it must be heritable functional adaptive and useful to its current function this means it must be passed down genetically must perform some function must increase the fitness of the individual and be adapted or made for the current function Pre adaptations are features that are evolved for one purpose but may be used to function for another purpose as well Exaptations are features that evolved for one function originally but have further changed over time to fit a new function Out dated adaptations are features that formed for a purpose but are no longer needed for that purpose By products are features that seem to be adaptations but are just a secondary part of a different adaptation