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Genes. Behavior Genetics. Environment. Genes . Alter nervous system & physiology. Alter gene expression. A lter behavior. Basic Genetics. Read pp. 28-30, and refresh your memory. Goals of Behavior Genetics. identify gene (genes) that control behavior
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Genes Behavior Genetics
Environment Genes Alter nervous system & physiology Alter gene expression Alter behavior
Basic Genetics • Read pp. 28-30, and refresh your memory
Goals of Behavior Genetics • identify gene (genes) that control behavior • identify gene interactions with products and environment • Measure heritability – statistical measure that indicates how strongly a behavior is influenced by genes. Varies from 0 – 1, where 0 is no heritability • Requires lots of individuals, often families
Goals of Behavior Genetics • Genomics – study of an organism’s entire genome. • Functional – know all coding and noncoding genes • Comparative – compare genomes in different species to get at evolution • Proteomics – know all proteins coded for by an organism’s genes, how they work together, and influence traits
Methods • Rule out environmental effects • INBRED lines – homozygous at all loci. Can compare 2 lines to get at environmental vs gene effects
Methods Rule out environmental effects EX: House Mice • Artificial Selection • If you can select, it must be genetic
Methods Rule out environmental effects EX: Fruit Flies • Induce Mutation • dunce in fruit flies • a memory problem
Methods Rule out environmental effects EX: Fruit Flies • Natural variation / hybridization • One gene – multiple traits; gene networks
Behavioral Variation and Genes • Genes – variation in alleles • Gene regulation • Relating this to humans and autism
Environmental Regulation • However, environment still has an effect; there is a gene – environment interaction • Read the examples on cichlids and songbirds
Environmental Regulation • Sneakers vs. immature males • Same age • Larger gonads, smaller body size, male body scent • Different genes expressed in brains
Environmental Regulation Gene Networks Different networks in different environments
Epigenetics • Stable alteration in gene expression without changes in DNA sequences • affect how tight the DNA molecule is • two methods • DNA methylation • histoneacetylation