Additivity or dominance the effect of one allele on

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Additivity or dominance: the effect of one allele on another allele at the same genetic locus Epistasis: the effect of one genetic locus on another independent locus Pleiotropy: the effect of a single gene on two or more phenotypic traits Polygenic: the effect of two or more genes on a single phenotypic trait Phenotypic plasticity: the interaction between genetic factors and the environment Genomic imprinting Effects (gene products) of a gene differ depending on whether inherited from mother or father Paradox of genetic information Proximate studies: genetic variation for behavioral variation is maintained in popuations despite strong directional selection Ultimate studies: why is genetic variation maintained if selection usually acts to decrease variation? Dependent on environment and environment is variable Lecture 8 Developmental flexibility A change in the development and production of a behavior based on variation in environment Examples: learned behaviors, hormonal effects on behaviors, just about everything except behavioral differences due entirely to genetic differences Kin discrimination: The capacity of an individual to react differently to others based upon their degree of genetic relatedness Social and aggressive behaviors: “associate with kin and be aggressive to non-kin” Sexual behaviors: inbreeding avoidance- “associate (mate) with non-kin” Learned kin discrimination
-imprinting -phenotype matching (aka the “armpit effect”), compare a foreign phenotype to your own phenotype -MHC alleles: genes that function in immune response and are some of the mosn,t variable (# alleles) genes known Major Histocompatibility Complex (MHC) MHC genes play a central role in immune recognition, influence odors and mating preferences in vertebrates MHC genes are among the most polymorphic loci: 1. There are a large number of alleles per locus (>100) 2. Large sequence divergence between alleles 3. MHC allelic lineages are old (older than recent speciation events). So for examples, any given human MHC allele is more related to some alleles from chimpanzees and gorillas than it is most other human alleles Normal versus cannibal Individuals can develop as normal predatory larvae or switch over to a cannibal form Switch to cannibalism affected by: population density, size differences, drying of water source, and genetic relatedness to others Innate kin discrimination: Genotype matching (aka “green beard effect”): a gene gives individuals both a conspicuous trait (such as green beard) and a tendency to act favorably to others with that same trait, mutual altruism between individuals could evolve (in the absence of kinship) Developmental Homeostasis Development homeostasis: development of specific behaviors despite variation in environment Category includes, but not limited to, innate behaviors Why do developmental flexibility and homeostasis exist?

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