sexual selection Flashcards
Anisogamy
what is anisogamy?
what is difference between males and women sex cells?
what is 2 consequences of anisogamy?
difference between males and females sex cells
males are small, highly mobile and dont require alot of energy to produce.
females are large, limited and require alot of energy to produce.
consequence:
1. no shortage for fertile males but female is “rare” source.
2. also leads to 2 different mating strategies : inter and intra sexual selection
inter sexual selection
what is inter sexual selection? ( 4)
what is runway process?
when female chooses
- female chooses quality of quantity
- females lose more resource than men if they choose substandard partners so that is why they are choosier
- so they pick a genetically fit partner who is able to provide resource. this leaves males competing against each other to be picked by the women.
- runway process = when female chooses a desirable charactersitics and this trait is inhertited by her son. for e.g if height is considered attractive then this would increase in the male population because females would mate with taller males and overtime produce sons which are taller and daughters who have preference for taller men.
intra sexual selection
what is intra sexual selection?
what do males prefer? + what is reason?
how do they do it?
when males compete to mate with a female
males prefer quantity over quality.
- they aim is to have as many partners as possible.
they compete with each other (other males) to present themselves as the most attractive mate encouraging features such as muscles which indicate to females the ability to protect both them and their offspring.
evaluation
3 evaluations on sexual selection
2 strengths
1 weakness
david buss (1989) conducted a survey on 10,000 adults in 33 countries.
- he asked them what their preference is. he found females preferred resource related characterisitics such as good finacial prospectus and ambition. males preffered reproductive capacity in terms of good looking, chastity and preffered younger females.
- this findings support sex difference in mating strategies due to ansigomay.
2.hatfield (1998) showed female choosiness. male and female psychology students were sent out across university campus. they approached other students and asked “i noticed you around campus and i find you really attractive would you go to bed with me tonight?” not a single female said yes whereas 75% of males said yes. this supports their evolutionary theory because it suggest females are choosier than males when it comes to selecting partners.
3) ignores cultural factors.
for e.g traditional view that women are looking for resourceful male to provide for her and her offspring is outdated because of the changes of role of women in workplace. bereczeksi argues social changes like women in workplace has affected female preference as they no longer looking for resourceful males. this shows mate preference cannot simply be understood by evolution
