Psych 230: Exam 3 Reproduction and Rhythms and sleep

What happens to female reproductive states after a male takeover?

Most females shift to cycling (fertility signals)

Why do males commit infanticide after takeover?

to accelerate female return to fertility

Evolutionary theory predicts that there will be strong selection for

individuals who are able to maximize their genes in the next generation

What is the female limiting factor to reproductive stress

time and energy

What is the male limiting factor to reproductive success

the number of fertile females they can mate with

Male strategy for reproductive success

mate with as many fertile females during your short tenure as the alpha male

Why do males kill unrelated dependent infants

accelerates the mother's return to fertility, feticidal and infanticidal males sire next offspring earlier

Female strategies for reproductive success

-select a mate with good healthy genes (an alpha is a good bet)

-invest in each offspring just enough to ensure survival on their own

-then, wean 1st offspring and start investing in next offspring

-live a long life

female counterstrategies to infanticide

confuse reproduction

accelerate reproduction

suppress reproduction

confuse reproduction

confuse males about paternity, confuse males about fertility

Accelerate reproduction

give up on current reproduction, immediately move on to the next reproduction

Suppress reproduction

wait to reproduce until a better time

bruce effect

induce abortion in pregnant females

vandenbergh effect

induce estrus in juvenile females

whitten effect

induce estrus in all adult females

What are the major glands in the HPG axis

hypothalamus, anterior pituitary, gonads (ovaries, testes)

What are the major hormones for the HPG axis

gonadotropin releasing hormone

(GnRH), luteinizing hormone (LH), follicle

stimulating hormone (FSH), testosterone (T),

estradiol (E2), progesterone (P4)

what are the 3 components of female sexual behavior

1) attractivity: stimulus value for a male 2) proceptivity:extent to which female initiates copulation 3) receptivity: responsiveness to male's sexual advances

What is anestrus?

A phase where females are not sexually receptive and often find males aversive

What is estrus?

The fertile phase where females are sexually receptive and seek males

Why do females suddenly seek out males during estrus?

Due to hormonal changes (especially estrogen increase) that alter brain and behavior

What system controls female sexual behavior?

The HPG axis (Hypothalamic-Pituitary-Gonadal axis)

What hormone is released from the hypothalamus to start the process?

GnRH (Gonadotropin-releasing hormone)

What do LH and FSH stimulate in females?

The ovaries to produce hormones

Gonandotropin inhibitory hormone (GnIH)

a hyptohalamic hormone that suppresses reproductive function

GnIH inhibits GnRH release, preventing...

gonadotropic hormone release (LS and FSH)

GnIH functions as a _________________________ on the reproductive axis

physiological brake, this brake must be lifted for reproduction to occur

resume on slide 21