relationships - evolutionary explanations Flashcards
Charles Darwin
noticed evolution favours some features that are attractive opposite sex.
they will make it moe likely that possessor will attract a mate and reproduce to pass on their genes.
therefore increasing reproductive success.
sexual selection
the process by traits that increase reproductive success are passed on to offspring.
any genes that promote successful reproduction are selected.
there are two types of sexual selection-inter sexual selection and intra sexual selection
inter sexual selection
female preferred stratergy
members of one sex evolve with preferences for particular charactersitics in the opposite sex because there characteristics will increase the chances of passing on genes.
intra sexual selection
male preferred stratergy
when members of same sex compete with each other for members of opposite sex. those who win can mate and pass on their genes.
what is anisogamy
the differences between male and female sex cells. it dictates the optimum mating strategies for males and females.
female sex cells
1 female ovum is produced once a month and only until menopause, and requires energy to produce.
females also make large investment in time, commitment and resources during and after the birth of offspring.
how does female sex cells influence partner preference- inter sexual
females seek long term relationships with males who have resources to provide for and protect her and her offspring. indicators include-
-mesomorph physique
-a strong jawline (indicator of testosterone)
-traits like intelligence which may translate to resources in future
how does partner preference in females increase reproductive success-inter sexual
females only have limited offspring, it makes no sense to have numerous partners. more. adaptive for females to carefully choose a male with desirable traits. increasing the chance that these traits are inherited by male offspring, so they are more likely to be chosen in the future generation of females. this way the females genes are propagated- known as sexy sons hypothesis (fisher)
male sex cells -inter
sperm are created continuously in vast numbers from puberty to old age and don’t requite much energy to produce. yhr later investment that id made In offspring is far less compared to females.
how does male sex cells influence partner preference-inter
males will seek short term relationships with females who are fertile and can produce healthy offspring. indicators include-
-youthful appearance (large eyes, smooth skin)
- a waist to hip ratio of around 0.7-an hourglass figure.
how does male partner preference increase reproductive success-inter
bc they can never be sure that a child was theirs, most adaptive behaviour is to mate with numerous fertile females in order to best inc limited chances that his genes can be carried onto future gens.
intra sexual selection traits
aggressive
competitive
intelligent
what is diasmorphia
intra sexual selection
body size and physical appearance - as males need to compete with other males for access to fertile mate, sexual selection with favour being tall, muscular and strong however these traits hold no evolutionary value or advantage to females
