evolution and natural selection Flashcards
(19 cards)
evolution
how inherited characteristics in organisms change from generation to generation
natural selection
process by which organisms become better adapted to their environment, live and reproduce to pass on their genes
fitness
measure of an animals ability to pass on it’s genes to viable offspring
adaptation
physical feature or behaviour that has been tested for it’s suitability to that environment
mutation
change in genetic structure that makes it different from others in the species
sexual selection
individuals that are successful in attracting a mate out-reproduce others in that population
genetic drift
not 100% of genes are passed on through reproduction
heritable traits
able to be inherited from parents to offspring
kin selection
natural selection favours a trait due to its positive effects on the reproductive success of an organism’s relatives, even it risks the organism’s own survival
altruistic behaviour
selfless and for the help of others in the species
direct fitness
when a gene gives a characteristic that benefits survival of individual
inclusive fitness
characteristic disadvantageous to individual but advantageous to relatives
group selection
individuals in a group survive more readily if part of a group
why may males be psychologically/evolutionary aggressive
- physically bigger, capable of providing food and protecting mates or offspring
- naturally more aggressive when resources are threatened or when hunting
- advantage for mate choice
why may females be psychologically/evolutionary aggressive
- less physically aggressive as it would be a disadvantage (long periods of pregnancy, breastfeeding and ensuring children survive)
- more verbal/emotional violence
Buss 1999
females achieved victory when competing for mates by denigrating other females to potential mates, makes them appear less attractive
Buss and Shackleton 1997
men tended to give in to the female and be more territorial around men
women threatened to leave men if they were unfaithful, using verbal aggression around other women
explains idea of natural selection as it guarantees offspring and means both survive
limitations of evolution to explain aggression
impossible to measure evolution and aggression directly
- aggression not universal e.g. physical aggression and interpersonal dominance in Kung San tribe is rare and discouraged while aggression gains status in the Yanomami tribe
- explanations of hormones and psychodynamics oppose
- reductionist
Allen et al 2016
archeological evidence of human on human violence from pre-historic graves found that sharp-force trauma correlated closely with times of scarcity like famine or drought
