What is Evolution?? Evolution is a theory based on substantial evidence. Def: All the changes that have formed life on earth from its earliest beginnings to the diversity that characterizes it today. Pioneers of evolution include: Darwin, Malthus, Lamarck, Lyell, Wallace Malthus (1766- 1834): Population growth theories http://www.blupete.com/Literature/Biographies/ Philosophy/Malthus.htm Lamarck (1744 – 1829): Lamarck developed two laws to explain evolution: the law of use and disuse, and the law of inheritance of acquired characteristics. http://en.wikipedia.org/wiki/Lamarck Lyell (1797 – 1875): Wrote Principles of Geology- said “The present is the key to the past” Wallace (1823 – 1923): Biogeography; first to form theory of natural selection Lamarck Law 1: (Use and disuse) In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears. Lamarck Law 2: (Inheritance of acquired characteristics) All the acquisitions or losses wrought by nature on individuals, through the influence of the environment in which their race has long been placed, and hence through the influence of the predominant use or permanent disuse of any organ; all these are preserved by reproduction to the new individuals which arise, provided that the acquired modifications are common to both sexes, or at least to the individuals which produce the young. So who was Darwin, anyway, and why do we care? Darwin relied on years of close observations and data to develop his theories on evolution. Most well known for descriptions of Galapagos Finches. He concluded that birds were adapting to their environment by having different beak sizes for their available food source. Revolutionized the theory of evolution at a very controversial time in history. Darwin proposed that species were evolving by process of natural selection – a process by which organisms best suited to their environment reproduce more successfully than other organisms. For natural selection to occur, has to be some certainties about the population: - Organisms have to reproduce - Has to be variation within the population - Traits have to have a genetic basis - Trait provides advantage to organism Some Vocab. To Know… Adaptation: an inherited trait that increases an organism’s chance of survival in a particular environment. Fitness: the ability of individuals to survive to pass on their genes. Population: interbreeding single-species group. Species: a group of organisms of a single type that are capable of producing fertile offspring. Which moth started to appear after the industrial revolution? Other evidence… Fossils Anatomy Embryology Biochemistry http://www.sciohio.org/Image97.jpg For Homework… Answer the following questions. Be ready to discuss your answers the beginning of class: 1. Why is there variation among all living organisms? Provide two concrete examples as to how this helps species survive. 2. Name one important person besides Darwin who helped influence the theory of evolution. What were some of their contributions and during what time period did they occur?