Sexual Orientation

Question 1

What are ultimate causes of sexual orientation

Answer 1

1. Maternal control of sex ratios

2. Evolution of non reproductive castes: present in social species

Question 2

What are proximate causes of sexual orientation

Answer 2

1. Sexual differentiation: Dimorphism

2. Sexual Dimorphism in brain and behavior

Question 3

All humans were hunter gatherers up until 10,000 years ago. Women have a lot of work to do bc often they’re able to provide as much as their husbands do. Polygany means that:

Answer 3

Husband may have more than one wife. Males don’t reproduce. Males need to have resources and compete for it to have a wife.

Question 4

If a woman gives birth to a son who can’t reproduce what happens?

Answer 4

Her fitness stops; she is no longer able to bring her genes to the next generation.

Question 5

Ladies fitness depends on how she helps her relatives which is called ____ selection. You don’t have to reproduce to have an effect on fitness.

Answer 5

kin

Question 6

_____ fitness is how much you contribute to the success of all your children.

Answer 6

Inclusive

Question 7

When menopause arrives, they continue to provide resources, knowledge and help to their relatives which also refers to _____ selection

Answer 7

kin

Question 8

What are advantages to controlling sex ratio?

Answer 8

1. parental investment theory: investing in offspring

2. Polygynous Mating Systems: requires greater investment in males

Question 9

What are mechanisms for controlling the sex of the offspring

Answer 9

1. non primate mammals: sex selective abortion in nutria: fat females get aborted
2. Non human primates: high ranking female baboons produce females in low quality sites and males in high quality sites.
3. Humans:
   - Abortions
   - Infanticide

Question 10

What is the Trivers Willard Hypothesis

Answer 10

If maternal condition is:

1. Good: competitive offspring
2. Poor: noncompetitive offspring

Question 11

A female might gain a better fitness by producing a male homosexual offspring. Why?

Answer 11

Heterosexual offpspring have early risk of death. Homosexual offspring don’t participate in sports; alleviates aggression

Question 12

What is the Rajput Case

Answer 12

Ex of infanticide

1. Most elite clans had no daughters
2. Subelites paid dowries to get their daughters into the highest caste thus impoverishing their sons
3. poorest castes welcomed daughters; they could increase their fitness

Question 13

Describe the Portuguese case

Answer 13

First borns remained near by. Later born males were sent off to war and their fitness suffered. The daughters were sent to cloisters where they became nuns.

Question 14

What are predictive adaptive responses

Answer 14

If the mother looks at env and thinks they don’t feel good about it influences how much effort their going to put in their child.

Question 15

Homosexuality may be an ____ response to environmental conditions

Answer 15

adaptive

Question 16

Before the war, there were less homosexuals in Germany. Therefore the prevalence of environmental stressors induces _____

Answer 16

homosexuality

Question 17

Mothers who are under severe stress bred _____

Answer 17

homosexual males.

Question 18

T/F; The age of the mother is higher in male homosexuals compared to the age of heterosexual males.

Answer 18

True

Question 19

Sry gene is on ____ chromosome which makes proteins called TDS. Expression of gene drives phenotype towards female or male. There are lots of chromosomal variations.

Answer 19

Y

Question 20

An ____ male is usually short and are infertile

Answer 20

XX

Question 21

Secondary sex characteristics are dependent on ______.

Answer 21

testosterone; masculinizes circuitry in hypothalamus and defeminizes in females.

Question 22

If there are no receptors for testosterone that works then there is no _____

Answer 22

testosterone

Question 23

_____ are derived from testosterone. It is produced in ovaries. Some estrogen is produced in males.

Answer 23

estradiol

Question 24

Testosterone and ______ are very important in developing of genitalia and brain

Answer 24

dihydrotestosterone

Question 25

In rats, estrogen is produced in ___ as well as with humans.

Answer 25

brain

Question 26

Number of cells in region depends on number of _____

Answer 26

offspring

Question 27

What does sexual dimorphism do?

Answer 27

1. correlates with behavior

Question 28

What is gonadal dysgenesis

Answer 28

Turners syndrome; you develop like a female; you don’t have any gonads. Petite individuals. Heterosexual females

Question 29

what causes androgen insensitivity

Answer 29

XY males; gender identity is that of a female. They prefer males.. The XY male has androgen receptor on X chromosome, testosterone is coming from testes even though has female phenotype. Brain doesn’t see testosterone, so makes too much of it, testes becomes cancerous so you have to remove testes and prescribe ESTRADIOL. No menstruation . But chromosomal she is a male.

Question 30

What happens in 5 alpha reductase deficiency

Answer 30

Converts testosterone to DHT. Need testosterone to masculine brain. need it to produce male genitalia. You get female genitalia

Question 31

what is Congenital adrenal hyperplasia

Answer 31

when the clitoris looks like a penis. The adrenals produce testosterone which produce genitalia in women. The brain is masculinized. A large fraction of these women are lesbians