EVOLUTIONARY EXPLANATIONS FOR PARTNER PREFERENCE (sexual selection and human reproductive behaviour) Flashcards
What is sexual selection and what does it suggest?
-a process of natural selection and the key factor underpinning human reproductive behaviour (Trivers, 1972).
-suggests evolution is driven by competition for mates and the development of traits that ensure a reproductive advantage.
What else does sexual selection suggest?
-that individuals with traits that increase reproductive success (e.g. physical attractiveness, strength, height) gain an evolutionary advantage because they are more likely to attract a mate.
-Alternatively, individuals with traits that enable them to outcompete rivals (e.g. physical strength) are also likely to gain access to a mate.
What happens after attracting a mate and successfully reproducing and what is the consequence
-their offspring will inherit their parents’ genes (e.g. for attractiveness or strength) and will therefore benefit from the same traits.
-Consequently, these respective genes will be passed on to future generations.
What happens to individuals without these traits?
-outcompeted, are unable to mate, and therefore will not reproduce and the genes underlying these traits will slowly disappear from the gene pool in future generations.
What are the two ways sexual selection operate?
intrasexual selection
intersexual selection
What is intrasexual selection?
Same-sex contest
-Individuals outcompete members of the same sex in order to gain access to mates Usually a male strategy which can involve aggression
-Preference for many mates (quantity rather than quality), i.e. polygamy
-Characteristics such as greater strength and cunning get passed on to future generations
What is intersexual selection?
-One sex competes for the attention of the opposite sex
Individuals evolve preferences for desirable qualities in the opposite sex
-Usually a female strategy which can involves choosiness
-Preference for single mate (quality rather than quantity), i.e. monogamy
-Characteristics such as having access to resources and attractiveness will get passed on to future generations
What is anisogamy?
the differences between male and female gametes (sex cells), which
result in different strategies for reproductive success- gametes are numerous, highly mobile and are replenished, whereas female gametes (ova) are large, static and
limited. This means there is no shortage of fertile males however fertile females are a ‘rare
What does anisogamy lead to?
a reproductive strategy of males seeking mates who are fertile
and have high reproductive value indicated by age and hip to waist ratio for males
what does anisogamy lead to for females?
Whereas for females anisogamy leads to females using a reproductive strategy of choosing a mate who is able to provide economic resources and support for her and her offspring
