Evolution of Monogamy and Grandmother Hypothesis

Flashcards reviewing the evolution of pair-bonding, factors selecting for monogamy, and grandmother hypothesis.

What is the main topic of the article by Schacht and Kramer (2019)?

Review of evolution of pair-bonding in humans, costs/benefits, and factors that select for monogamy or not.

According to the lecture, what factors should be considered when examining monogamy?

Sexual dimorphism, testis size, concealed ovulation, infanticide and kin discrimination, and parental care.

What are some factors that select for monogamy according to Klug (2018)?

Adult density, adult sex ratio, sexual selection, spatial distribution of potential mates, operational sex ratio.

What aspects of sexual dimorphism (SD) are discussed in the lecture?

Degree of sexual dimorphism in humans compared to other apes/primates, relationship to monogamy, measurement, relation to competition, level in ancestral hominids.

How is testes size related to mating systems, and what does it predict?

Related to mating system. Human testes size pointing towards selection for monogamy. Sperm midpiece prediction.

What are the effects of concealed ovulation on male competition and mate-guarding?

Whether concealed ovulation increases or decreases male-male competition and mate-guarding.

How does social structure affect infanticide risk, and how can females minimize this risk?

How social structure affects infanticide risk, ways females minimize this risk, and whether a system is polygynous.

What trade-offs do males face when providing for offspring and how does this affect mating systems?

Trade-offs males experience when provisioning for offspring, changes in fathers, effect of sexual division of labor on mating systems.

What is Monandry?

Female mates with one male in her life before egg-laying

What is Monogamy?

One female pairs with one male (social) or mates with one male (genetic)

What is Polyandry?

One female mates with > 1 male

What is Polygyny?

1 male mating with >1 female within the group

What is Promiscuity?

Female infidelity arising with males outside the pair-bond or outside the group

What is Between-attempt infidelity?

Identity of partner changes between reproductive events

Define 'Pair-Living' in terms of social organization:

Two adults live together within a common home range and associate either continuously or intermittently

Define 'Pair-Bonded' in terms of social structure:

Manifest a discernable attachment to one another, to the exclusion of other opposite- sex individuals

Define 'Sexual Monogamy' in terms of Mating System:

A female and a male maintain an exclusive mating relationship during at least one reproductive season

Define 'Genetic Monogamy' in terms of Mating System:

A female and a male reproduce exclusively with one another for at least one reproductive season

Define 'Biparental Care' in terms of Care System:

Both members of a pair regularly perform behaviors with presumed positive effects on infants

Define 'Cooperative Infant Care' in terms of Care System:

Other individuals, in addition to putative parents, regularly perform behaviors with presumed positive effects on infants

What is the 'grandmother hypothesis'?

The influence of grandmothers on offspring survival and reproductive success.

How does the presence of a grandmother affect offspring survival?

It can increase the survival rate of offspring.

What is menopause?

How menopause evolved and its prevalence among mammals, focusing on toothed whales and humans

How are social systems similar in species that experience menopause?

Social system, reproductive skew and inbreeding

What types of grandmothers are there?

Maternal vs paternal.