Sexual selection

What is the evolutionary explanation for partner preferences?

Use terms of adaptiveness and reproductive success

Natural selection= trait eg aggression genetically inherited by one generation from another =must have specific value for species either to adapt better 2 env and survive

Sexual selection= trait genetically inherited by one generation from another that attracts a mate and helps have healthy offspring

What is sexual selection as a theory of behaviour?

Sexual selection=evolution of characteristics that provide reproductive advantage as seen as more attractive to opposite sex -rather than survival advantage

Attributes increase. Reproductive success passed on and Become exaggerated over succeeding generations/offspring

What is anisogamy

Differences between male and female sex cells

Male : v small and mobile, created continuously in vast numbers from puberty to old age , don’t need lots of energy 2 prod,no shortage of fertile males

Female= large, prod at intervals for limited fertile years, large investment of energy , rare resource

= diff mating STRATS

What is inter sexual selection?

Mate choice= females

Egg= rarer, have to carry offspring 2 term + care 4 them after= greater investment of energy,time,resources= PAYS 2 B PICKY

=optimum strat=select genetically fit partner able and willing 2 provide resources =leaves males competing 4 opportunity 2 reproduce= females desire determines what’s passed on 2 offspring eg height

What is intra sexual selection?

Mate competition= male

Quantity over quality = optimum start impregnate as many f as possible as have minimum and post natal responsibilities

Evolutionary developed traits=allow male competition 4 female mate

Winners get 2 mate and pass on genes 2 next gen

=physical dimorphism =obvious diffs between m and f eg bigger stronger males= due 2 size matters when competing=evolved 2 have traits eg bigger

=controversial psychological and behavioural consequences= competition gives rise 2 aggression and protective behaviours= esp bad in modern day

What are the consequences of anisogamy and inter.intra sexual selection?

Partner pref

Males=youth, chastity ,fertility =suggest reproductivity

Females= genetically fit ones w resources eg intelligence , status, financial prospects

Research support female choosiness

Clark and Hatfield 1989

Volunteers asked students of opp sex “I’ve noticed u around campus, i find u v attractive, will u go to bed w me tonight?”

Gender diffs 75% of m agreed NO F SAID YES

=shows both strats

Research critique more complex

Penton voak et al 1999

Pref 4 masculine features when most fertile

But feminised features for long term mate

Masculine =healthier Immune system =advatageuous 2 off spring

Feminine=kindness and cooperation=good 4 long term

Mate choice= variety of factors Not just genetic fitness

Research support -prefs based on anisogamy

Buss 1989 33 diff countries 10000 diff adults

Asked qs on atributes and age theory predicts are imp

Women= greater value on resource characteristics eg financial prospects, ambition

Males= reproductive capacity, eg physical attractiveness and youth

Sex diffs in mating strats THERE and partner prefs

Can be applied across vastly diff cultures=reflect. Fundamental human prefs = DUE 2 EVOLUTION =UNIVERSAL ish