evolution Flashcards
what are genes
a unit of heredity that contains DNA carrying information from one generation to the next. each gene influences development by triggering the production of enzymes and proteins involved in production of cells. contains a set of instructions forming the genotype and phenotypes.
outline some A01 for evolution
genes of dominant and recessive
genes can be sex linked
we get half off our mom and dad
random fertilisation, independent assortment and crossing over of chromosomes leads to variation.
environment can also effect genes ie skin colour, weight and accent.
what is evolution
inherited characteristics in organisms change from generation leading to differentiation through natural selection (the better adapted, the more likely they are to survive and pass on alleles to their offspring). typically arise due to mutation. use the acronym MASRCA
how is aggression a product of evolution
exposing one’s weapons were the components of the early stages of combat. But once enemies began to recognise these behaviours as signals of impending aggression, a survival advantage occrued to attackers that could communicate their aggression most effectively and intimidate their victims without actually fighting. As a result, elaborate threat displays evolved and actual combat declined. Animals display aggression in order to minimise actual physical contact to reduce chances of injury or death. As such, they follow innate procedures of ‘display’ often to attract a mate.
give research to support
Kettlewell in the 1950s found evidence that moths that fitted the environment and were not conspicuous lived to reproduce; non-fitting moths did not, concluding that birds would eat more of the moths they could see. 27% of moths in industrial woods (areas blackened by sooth and industrial waste) were dark compared to 13% being light coloured.
low generalibailty as he uses animals rather than humans.
Clark and Hatfield study found that 75% of men agreed to have sex with the female researcher. Supporting the idea that men have an inherited thirst to breed and pass on genetic to offspring.
Singh 1993 found males up to a point like any hip and waist size attractive as the ratio of one to another is 0.7
Waynforth and Dunbar found women typically describe themselves as flirty exciting and sexy in ads
how can mating lead to jealousy
Mate competition includes rivalry and can lead to feelings of jealousy and jealous behaviour. Jealousy is thought to be a genetic behaviour found in all human cultures, suggesting a biological predisposition. In the natural world, sex leads to babies and thus the continuation of the family, community or species. This would be very important for early humans, as the community or group would need a constant supply of new members if it was to continue.
give research to support mating jealousy
Buss & Shackleton (1997) gathered evidence to see what men do in response to feeling threatened in a relationship to see if there is evidence for the idea of natural selection. The researchers found men tended to give in to the female, giving her everything that she wanted and they were threatening to other males around. Both these strategies would aid the survival of the male’s genes.
how can aggression occur due to limited resources
ie food and water that are needed for survivalThose who successfully defend food and shelter would survive longer and reproduce, so any such behaviour can be inherited as genes leading to such aggression would survive
Why do women look for an older mate
They want security and stability. They associate older men with money, wealth and security do they can raise their offspring without financial burdens
Why do men look for a young mate
This is so they are young, sexy and fertile so they will be successful in having their offspring and carrying their genetics on.
