Lectures for Animal Behavior

Animal Behavior - Biology 4200/5430

Bowling Green State University, Fall 2009

Behavioral Genetics

A devil, a born devil, on whose nature
Nurture can never stick; on whom my pains
Humanely taken, all, all lost, quite lost
-- The Tempest, William Shakespeare 1610

"In 1859 I obtained a very fertile descendant with large, tasty seeds from a first generation hybrid. Since in the following year, its progeny retained the desirable characteristics and were uniform, the variety was cultivated in our vegetable garden, and many plants were raised every year up to 1865" -- Gregor Mendel in a letter to Carl Nägeli,1867

Genetics

The <Phenotype> (observable characteristics of an organism) emerges from an interaction of its <Genotype> (the organism's genetic composition) with environmental factors. Population genetics concerns itself with fundamental concepts that influence the relative occurrence of genes.
<Gene>: functional unit of heredity which is composed of DNA and specifies the structure of proteins (e.g., serum albumin)
<Locus>: functional unit of heredity on a chromosome that specifies the structure of proteins; Monomorphic Loci: gene frequency of the common allele 0.95 or 0.99; Polymorphic Loci: any locus which demonstrates more than one allele with frequency > 0.05

Mendelian Genetics

Mendelian Genetics discusses the predicted outcome of sexual reproduction in situations where two or more allelesare present at one locus. The genetics of many diseases can be characterized in simple Mendelian terms (presence/absence) while most morphological/behavioral traits (body size, intelligence) are the result of multiple genes. Although each gene may well follow a simple Mendelian pattern, their overall result is not easily characterized in these terms - quantitative genetics

Behavioral Genetics

<Polygenic Trait>: Trait that is under the control of multiple genes
<Pleiotropy>: The situation under which a gene may influences multiple phenotypes (i.e. ther is no 1:1 correspondence between gene and behavior)
<Heritability>: Statistical estimate of variation in a trait that is attributable to genetic differences among individuals within a group. It is commonly expressed as a proportion.
- Genetic: Characteristic determined by genes Example: # of arms humans have
- Heritable: Degree to which genetic differences among people account for behavioral differences among people.(What accounts for individual differences?)

Examples

Hygienic bees
Migration paths of European warblers
FosB mutant mice
Vasopressin and meadow vs. prairie voles

Reading Assignment

Chapter 5: Behavioral Genetics

WikiBooks

Behavioral Genetics

Links of Interest

Food for thought:

57% of monozygotic twin brothers of gay men are gay
24% of dizygotic twin brothers of gay men are gay
50% of monozygotic twin sisters of gay women are gay
16% of dizygotic twin sisters of gay women are gay

What do you make of these numbers?

last modified: 9/24/04