Anth 1102 1st Edition Lecture 11Outline of Last Lecture I. Genetics and Human Variationa. DNA, Genes, and Traitsi. DEFINITIONSII. DNA & Meiosis a. Two types of DNA do NOT mix/cross overOutline of Current Lecture I. Gregory MendelII. Dominant vs. Recessive genesIII. Key points about genetics/DNA for this courseIV. Four aspects of genetic variationV. Implications of Genetic Variation for Race/Ancestry Current LectureI. Gregory Mendel: developed idea of genesa. Pea plant crossing experimentsb. Monk living in the mid 1800sII. Dominant vs. Recessive Genesa. Mendel came up with thisb. Dominant-phenotype/expressed c. Recessive-genotype/secretd. First Generation (F0): gg YYe. Second Generation (F1): Ygf. Third Generation (F2): III. Key points about genetics/DNA for this coursea. Phenotype is a result of interaction between all your genes (dna/genotype) and the environmentb. Genotype consists of genesc. Genes are sequences of DNA that code for particular traitsd. DNA is a long double-strand containing 4 types of moleculesThese 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.e. The sequence of these molecules provides the codef. The DNA strands are organized into chromosomesg. Each chromosome consists of two strands of DNAh. Humans have 23 pairs of chromosomes and mtDNAi. 23rd par are the sex chromosomesi. Each pair includes one chromosome inherited from each parentj. Inheritance determined by meiosis (creating sperm/egg cells)k. This is important for evolution because of variationIV. Four aspects of genetic variationa. 1. Random selection during meiosisi. Each sperm/egg cell is different and unique b. 2. Crossing over during meiosisc. 3. Mutation during meiosisd. 4. Sexual reproduction V. Implications of genetic variation for race/ancestry1. Mixing makes tracing genetic ancestry difficult2. Genetic variation is continuous3. Limited tracing of father’s line (through yDNA) and mother’s line (through mtDNA) possible. VI. Evolution by natural selectiona. Modern synthesis of evolution: natural selection, genetics, and DNAb. Natural selection: the process by which the forms most fit to survive and reproduce in a given environment do so in greater numbers than others in the same populationVII. Darwin’s notion of natural selection had three parts:a. The struggle for existencei. Limited resources, unlimited reproductionb. Variation in fitnessc. Inheritance of variation VIII. Myths about evolution by natural selectiona. Evolution is a theory about the origin of lifei. FACT: evolution is a theory about what happened AFTER life originatedb. Evolution implies that life evolved randomly, by chancei. FACT: evolution selects for organisms that re best adapted to changes in the environment or the ecosystemc. Evolution results in progress: organisms are always getting better through evolutioni. FACT: evolution results in organisms being able to survive better in a givenenvironment, but this is not always progress.d. Individual organisms can evolve during a single lifespan.i. FACT: only changes in genetic material get passed on to offspringe. Evolution only occurs slowly and graduallyi. FACT: yes, often, but it can also happen very quickly in response to large changes in the ecosystemf. Humans are no longer evolvingi. FACT: there are still important changes to human survival g. Natural selection involves organisms trying to adapti. FACT: organisms don’t try to adapt. They try to survive. They are sometimes better able to survive because of particular mutations. h. Natural selection acts for the good of the speciesi. FACT: natural selections acts only on individualsi. Natural selection is about survival of the fittesti. FACT: natural selection is about the survival of the fit enough j. Fittest means strongest, healthiest, fastest, and largesti. FACT: the more fertile offspring an organism produces, the fitter it is. In some cases, this is NOT the strongest, fastest, or