Weeks 9 and 10 Flashcards
Science is a ____________
social process
● Heteronormative binaries
limit ___________
LGBTQ community in
STEM
Limits different viewpoints from
others with ______________
unique experiences
● Sexual diversity of animals
viewed by_____________ can leave interesting
observations unexplored
a heteronormative
lens
_____________ routine assumption of
heterosexuality and associated behaviors,
family structures, life history traits, etc
Heteronormativity:
___________ assumption and
naturalization of a binary division and
conventional alignment of gender identity and
sex
● Cisnormativity:
● Consequences of heteronormativity
Normative traits are naturalized, unquestioned, and
unexamined
b. Makes some variation invisible, or the visible
variation is deemed odd
Same-sex behavior occurs in _______________
of mammal and bird species
~15-30%
IN ● Reptiles: Male garter snakes can
emit ____________
female pheromones
New hypothesis: __________________
○ “Maybe embryos use early hatching to get away from
snakes, but animals in the water select against early
hatching while tadpoles are more likely to be eaten”
● Escape-hatching behavior
adaptive plasticity and hatching
timing
● Herpetologists considered hatching as a
developmental event, not behavioral
● However, ___________
there is indeed an environmental
stimulus that causes early hatching!
_____________ suffocate under water
Terrestrial eggs:
___________ dry out on land
Aquatic eggs:
Hourglass tree frogs evolved to
lay terrestrial
eggs (ancestors had aquatic eggs)
● Boundary between terrestrial and aquatic is
____________
more permeable than previously thought
experiments revealed_____________________ between terrestrial and aquatic egg laying
plastic behavioral
choices
Male glass frogs known to
brood and guard eggs
Experiments revealed that hydration
from female frogs
sitting on eggs
provided essential protection from
predation and drying
● Changed perspective: now know that
________________
ALL glass frogs have and need parental care ○ Female and male biparental care are widespread ○ No sex bias in care duration or level of protection
Takeaways
- Weird observations matter, beyond normative expectations
2. Disrupted binaries reveal variation that wasn’t thought to be possible
what are the organizational effects from genes
usually involves the SRY gene
Y chromosome sry gene → testis → testosterone →
__________
male phenotype
XX chromosomes → absence of hormones →
_____________
female phenotype
■ Estrogen feminizes during _________
puberty
Activational effects from _________
adult steroids
● Environmental socialization (nurturing) leads
to gender
___________
○ Arises from sex
Rats: affected by perinatal hormones
○ Blocked aromatase around time of birth
○ Males had preference for ___________
control males
● __________________
○ Overproduce androgens
Congenital adrenal hyperplasia (CAH)
○ Males born w/o genitals, transformed into female with surgery
○ Male typical sexual attraction
● Cloacal/Vesical Exstrophy
○ Higher incidence of __________ in CAH females indication that
Endocrine modifications impact _________
homosexuality
sexual orientation
Other modifications:
○ Androgen insensitivity, 5a-reductase deficiency, Treatment of mothers with DES,
Various chromosomal anomalies
the show that _________________
Possible organizational effect from hormones → affects
sexual orientation
what are the two sex differences linked to homosexuality
- digit 2:digit 4
- long bone length
____________
● Ratio is decreased (masculinized) in homosexual women
Digit 2: Digit 4 (2D:4D) ratio
● Growth of bones is influenced by
prenatal T
have a smaller 2D:4D ratio
● Males
Long bone width/length ratio
_______ have larger hand width/length ratio
● Males
lone bone ● Ratio is l__________ in homosexual women
larger (masculinized)
Suggests that ___________ is above average for
homosexual women
perinatal exposure/action of T
____________
● Sounds given off by inner ear when responding to sound
Otoacoustic Emissions (OAE)
● OAE is higher in number and amplitude in
females than males
● OAE is ___________ in homosexual women
lower (masculinized) i
Brain activation by sexual odors
● Compounds derived from
androgens or estrogens similar to pheromones
________ activate hypothalamus of straight men
● Estrogens
__________ activate hypothalamus of straight women and homosexual men
● Androgens
● Group of cells in anterior hypothalamus
INAH-3
● Males have ___________
larger INAH-3 than females
_________ INAH-3 in homosexual men
Smaller (feminized)
How did they get exposed to atypical levels of hormones
● Largely unknown ● Hypothesis: ○ Stress ○ Endocrine disruptors ○ Inflammation of brain
Genes might participate to control sexual orientation
○ If a family has one homosexual member,_________________
○ Twin studies: higher concordance of ___________
● Search for genes has been largely unsuccessful
chance of another one is higher
homosexual orientation in identical twins
MAGE-11 (melanoma associated antigen) located at Xq28 (X chromosome)
○ Epigenetically regulated gene that increases sensitivity to __________
androgen (receptor coactivator)
■ Demethylated following androgen deprivation → _________________
○ Only present in humans and primates: sexual orientation is only a human phenomena
hypersensitivity to androgens
Mage 11 ○ Might show a link b/w
genetic and hormonal controls in the brain resulting in sexual orientation
○ Not the case, so epigenetics, gene expression, or something else could have
a causal role
○ If sexual orientation was due to differences in hormone [ ] and action, we would lots of
ambiguous sexual orientations
________ might help with controlling the sensitivity to testosterone
Epigenetics
______________ Increase incidence of homosexual males to mothers that have previously had
other boys
Older Brother Effect
Explanation of the older brother effect is that Mothers develop antibodies for ___________
○
neurologin 4, a Y-linked protein
Neuologin 4
Accumulate in mother as a result __________
○ Antibodies affect development of brain
○ Increase incidence of homosexuality
foreign embryo (XY)
Heteronormativity and cisnormativity affect the way we _________________
observe, record,
analyze, etc. data
● Frogs teach us things; not everything follows a
binary
○ Unlikely these phenomena escape biological control and left open to ______
social influence
Observed phenomena suggest there are biological influences to _________ besides social influences
○ Organizational effects of hormones
○ Genetics and epigenetics
○ Older brother effect
sexual orientation
● Sexual orientation is an _______ (when viewed through biologist lens)
evolutionary effect
