BCOR 12 1nd Edition Exam 1 Study Guide Lectures 1 7 Lecture 1 January 12 Introduction to Descent with Modification What is evolution What are homologous structures What are examples of evidence of evolution Evolution is the overarching theme in biology that allows us to understand the unity and diversity of life it is both a pattern and a process Homologous structures are structures that are similar in different species because of common ancestry Homologous structures vestigial structures embryology and fossils are some examples of evidence of evolution What are the key observations of life There are three 1 Organisms are well suited for living in their current environment 2 Living organisms share many characteristics ex DNA and this demonstrates the UNITY of life 3 Earth has a large rich DIVERSITY of living organisms Evolution helps explain the UNITY and DIVERSITY of life on Earth Lecture 2 January 14 What is artificial selection Would this occur in the natural world Artificial selection is selective breeding of plants and animals by humans This would most likely not occur in the natural world for the characteristics the humans are breeding the animals to look may not have benefitting the plant or animal in the natural world What was Lamarck s Theory of Evolution Was he correct What was the main flaw in Lamarck s Theory Lamarck s theory was based on two parts 1 Use and disuse the parts of the body that were being used most often will grow longer or in someway evolve to benefit the organism and its survival during its lifetime 2 Inheritance of acquired characteristics the characteristics that the organism acquired during its life will be passed on to its offspring Lamarck s theory was incorrect The main flaw in Lamarck s theory was that he thought beneficial characteristics ex A cat s claws to climb trees were obtained during the organism s lifetime when in reality they are already born with those characteristics He thought the DNA of an organism could change during the lifetime but we know that this is indeed false What is adaptation What did Charles Darwin note on his journey to the Galapagos regarding the birds on the islands in relation to the mainland birds What is variation Adaptation is inheritance of characteristics of an organism that enhances its survival and reproduction in a particular environment Charles Darwin noted that the birds on the Galapagos were similar and yet distinctively different than the birds on the mainland He also noticed variation between birds within the islands Variation is the differences between members of the same species What is Natural Selection What drives natural selection What is the ONLY way to get a new allele in a DNA sequence What is gene expression Natural selection is the process where organisms inherit certain characteristics that make them much more likely to survive and reproduce and pass on these chosen characteristics than those with other less favorable characteristics Variation among species is what drives this force The ONLY way to get a new allele is a mutation in the DNA Gene expression is expressing DNA as protein Genotype phenotype What were the inferences and observations that Charles Darwin made that made him hypothesize that all living things are some how related or connected to one another Darwin s three main observations were 1 Within a population there is a great variety in traits a Ex Not all humans look the same We can be of different skin colors height weight eye color etc 2 Traits are inherited from parents to offspring a This is through DNA 3 Species often produce more offspring that the environment can support Due to lack of food and other resources many offspring do not survive He then made the following inferences 1 Individuals who had inherited traits that infer a high survival and reproduction in a given environment will leave more offspring 2 This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable trains in the population over generations In other words those who have the favorable traits to survive will produce offspring with the traits to survive and the favorable traits will later become the norm of the population over the years What were the two main idea of Darwin s book that these inferences and observations led to 1 Descent with modification explains life s unity and diversity 2 Natural selection brings about the match between organisms and their environment What are two important points of Natural Selection to keep in mind 1 Natural selection is an editing mechanism not a creative force 2 Natural selection favors traits that increase fitness in the current local environment In other words Natural selection edits out the unfavorable traits so that the favorable traits that best suit the population to survive in their environment at that current time will pass on to further generations The favorable traits are bound to change over time as the environment changes Lecture 3 January 16 What is microevolution The change in allele frequencies in a population over time What are the four mechanisms that drive the evolutionary force What are there definitions 1 Natural selection definition found above it is a directed change 2 Gene flow random change due to migration of new alleles in and out of a population 3 Genetic drift random fluctuation of allele frequencies from one generation to the next 4 Mutation random change in the nucleotide sequence in an organism s DNA this occurs on the individual level What is the gene pool of a population What is a population exactly Gene pool of a population is all the alleles present in all of the individuals of a population A population is a group of organisms of the same species that can interbreed and produce fertile viable offspring What is the Hardy Weinberg equation s What does it help us determine What are the HardyWeinberg Five Assumptions What does it mean if one of these assumptions is violated There are two Hardy Weinberg equations p q 1 and P2 pq q2 1 The first represents the frequencies of the dominant and recessive genes These frequencies must add up to one The second is the frequencies of the genotypes in a population The Hardy Weinberg equations help us determine if a population is evolving based on if the observed frequencies of the population match or are close to the expected frequencies of a population The Hardy Weinberg Five Assumptions are I II III IV V NO mutations Random Mating no sexual selection