Evolution and Genes

• the evolutionary theory of aggression is that aggression is a result of natural selection, and that aggression is a result of the struggle for survival
• gene: a sequence of DNA that codes for a specific protein or RNA
• Genetic drift: The random change in allele frequencies in a population due to random mating
• Genetic mutation: A change in the DNA sequence of an organism that can be passed on to offspring
• (strength of the evolutionary theory of aggression) high levels of testosterone are linked to typically male attributes like spatial awareness and aggression.
• (Weakness of the evolutionary theory of aggression) The ideas can't be scientifically tested and there are limited fossil records.
• sexual selection- a form of natural selection, individuals that are successful in attracting a mate out-reproduce others in the population.
• Genes are investigated using twin and adoption studies.
• Twin studies involve comparing monozygotic (identical) twins with dizygotic (fraternal) twins.
• Supporting evidence- Heston (1966)- Adoption study into Psychiatric Disorders in foster home reared children of schizophrenic mothers.
• Heston found that adopted offspring were more likely to develop psychiatric disorders if their biological mother had been diagnosed with schizophrenia than if they hadn’t.
• Supporting evidence- Gottesman and shields (1966)- Twin study- investigated the relative importance of genetic and environmental factors in determining schizophrenia is MZ and DZ twins.