Evolutionary Biology BIOL 3350 Dr Lisa Rapaport Lecture 1 Notes What is Evolution I Evolution unifying theory of biology A What does evolutionary theory explain 1 Diversity between species and within species uniqueness 2 Differences and similarities between organisms Adaptive evolution overtime animals adapt to their specific environments in order to become better accustom to them advantageous mutations are passed onto offspring Example human arm dog foreleg and seal slipper all have bones of the same type corresponding bones these structures have been modified to grasp run and swim all derived from a common ancestor 3 Some characteristics can be useful while other can be non useful or useless Whales have a femur bone and a pelvis bone that are completely dissociated from the animal s axial skeleton these bones are no longer used in the whale since it is aquatic this shows that a whale was not always aquatic it may have been a land animal before it is likely that its ancestors were land animals B What is evolution 1 Evolution the process by which different kinds of living organisms are have developed and diversified from earlier forms during history of the earth change over time Evolution involves gradual change overtime that allows an organism to become better adapted to its environment evolution does not occur in a single generation it takes many generations 2 Darwin defines evolution as a process of descent with modification or change from common ancestors Modification change of genetic information Common ancestry means that all of life shares a history of ancestors that are shared different species of animals are all derived from a common ancestor species have differentiated over many many years as different organisms adapt to their own unique environments different habitats result in different adaptations 3 Evolution happens within populations Populations evolve individuals do not Evolve through alterations in the allele frequencies within a population over time and across generations 1 4 Descent with modification Microevolution slow small alterations Macroevolution major evolutionary changes over time Microevolution and macroevolution are the same process just on different scales of extremity both lead to changes over time C How does evolution happen 1 Variation Mutation is a significant source of variation advantageous mutations are passed onto more offspring because if the mutation is advantageous the organism will likely be able to survive longer and reproduce more thus increasing the number of offspring that that organism produces more offspring more chances to pass this advantageous trait on to the next generation Genetic recombination results in variation Chance random variation Most mutations that occur are maladaptive and only some are Selection directed variation adaptive Example refer to graphs in Lecture 1 PowerPoint The beak depth of the birds got fatter after the drought A lot of the birds with smaller beaks died because they could not process the hard seeds D Why is evolution a theory 1 Evolution is a theory because it is an explanation based on observation experimentation and reasoning and it has been tested and confirmed as a general principle helping to explain and predict natural phenomena Hypothesis a falsifiable proposition a proposed testable explanation for a phenomenon Fact a piece of information that is indisputable due to its incredible extent of support E What does evolution do for you 1 Health and Medicine Predicts origin and spread of disease thus can help contain it and minimize the amount of people that it affects Helps to produce new vaccines can open doors to new medications and treatments in order to save and protect lives minimize illnesses and deaths Genetic counseling the giving of advice to prospective parents concerning the chances of genetic disorders in a future child Gene therapy treatments Gene therapy is an experimental technique that uses genes to treat or prevent disease In the future this technique may allow doctors to treat a disorder by 2 2 Agriculture and natural resources inserting a gene into a patient s cells instead of using drugs or surgery Highly active anti retro viral therapy HAART uses a combination of drugs to attack HIV virus to prevent it from adapting to all types of drugs administered increase chances of survival refer to corresponding graph in Lecture 1 PowerPoint Produces a variety of plants and animals through artificial selection artificial selection allows scientists to pick and choose which characteristics they want a plant or animal to have and which characteristics they do not what it to have Genetically modified organisms GMOs GMOs are plants or animals that have undergone a process wherein scientists alter their genes with DNA from different species of living organisms bacteria or viruses to get desired traits such as resistance to disease or tolerance to pesticides Preserve genetic diversity lessens extinction genetic diversity allows populations to best adapt to their habitats over time advantageous characteristics are passed onto offspring Allows us to directly help conserve specific habitats and populations Helps us to restore aspects of the environment Helps maintain biodiversity this is important for species to be able to adapt to their environments 3 Environment and conservation 3