role of evolution Flashcards
what is evolution?
Evolution is the gradual development of different kinds of living organisms from earlier forms during the history of the Earth.
how does evolution occur?
through a process known as natural selection (survival of the fittest)
what is natural selection?
the process in which organisms better adapted to their environment are healthier, live longer and reproduce more frequently, passing on the genes that made them reproductively fit onto their offspring.
what is an example of natural selection ?
as giraffes rely on leaves for food, they would be better adapted to the environment if they had the ability to reach the leaves higher up. Every now and then, a genetic mutation (a change in the genetic structure of an animal or plant that makes it different from others of the same kind) which meant some giraffes had a slightly longer neck. They then breed with giraffes and gradually giraffes with small necks have died out.
how does evolution explain behaviour (general)?
Our brain is built according to the genes we inherit from our parents. The structure and function of our brain have evolved to adapt to our environments - therefore our behaviours are a product of evolution.
what does evolution say about how physical strength was important in surviving?
males who were physically bigger and stronger were the most capable of providing food and protecting their mates and offspring. therefore males who were naturally more aggressive when their resources were threatened, or when out hunting had an adaptive advantage.
how does evolution explain why males act aggressively and jealous over their partner?
jealousy takes on a form of aggression as a male needs to pass on their genes, so another male competing for a female’s attention would threatens that. The male who aggressively defended ‘his’ female would have been the one who reproduced and whose genes survived. Therefore, jealousy and the resulting aggression can be seen as a survival trait.
how does evolution describe why females are less physically aggressive?
it would be a disadvantage to females who spend long periods pregnant, feeding and looking after vulnerable children in order to aid their survival – to put themselves at risk by engaging in conflict and hunting.
what did Buss (1999) suggest?
Buss (1999) proposed that females would still be in competition for the best mates, but achieved this by criticising other females to potential males partners to make them seem less attractive.
what might we expect to see if these explanations for agression our true?
- differences in the brain structure of males and females
- similar signs of this animals who share similar genetics to humans.
what is a weakness of evolution?
the fact that the idea is reductionist means that a whole situation is not taken into account. Darwin focussed on genetic transmission and behaviour can be learned in other ways, e.g., through observation.
what can’t evolution tell us?
why females can also be physically aggressive.
what did Buss and Shackleton (1997) find?
that men tending to “give in” meaning giving their partner everything they wanted as well as being hostile to male competitors which supports the theory.
- suggests the need to keep females happy in order to pass on genes.
what did Wilson &; Daly (1985) find?
Wilson & Daly (1985) studied murders in Detroit and found that the majority of perpetrators and victims were young men. 29 of the cases they looked at were murders that had resulted from ‘escalated showing off’ disputes and only one of these murders resulted from a dispute between women.
what is meant by the EEA?
Environment of evolutionary adaptation EEA
- the conditions that prevailed in the environment at the time that a species was adapting in response to )
