Exam 2: Week 8 Flashcards
what are the human growth patterns? (3)
- In infancy the height velocity is high but in childhood the speed of growth slows down through juvenile
- In adolescence females will first increase height velocity and then males later
- Eventually stop growing in teens and early 20s
body tissue growth; components of it? (4)
the organism has an energy budget directed toward certain things during development
- Maintenance
- growth
- gene copies
- reproduction
average age of human weaning
2.5 years compared to 5 for chimps and 7.7 for orangutans
- Babies have a lot of brain growth ⇒ up to 5-6 years
- They also grow teeth before they are replaced later as adults
- The body doesn’t grow as much until adolescence
- Reproductive systems are kept on hold until about the age of 15-20
age at first birth for humans vs chimps?
19.5 vs 14.9
- menarche and first birth are much later than other apes
menarche
the age females first get their periods
why are human infants weaned early for their body size?
they retain small, weak milk teeth much longer than other apes ⇒ keep our teeth longer because we cook
what are major changes at adolescence? (9)
- bones
- muscle
- fat
- hair
- sweat
- oil
- blood
- sperm
- sex
what are changes in bone size at puberty?
- Women: wider hips ⇒ begin growing a little bit earlier than boys
- Men: broader shoulders, taller ⇒ grow faster and longer
why do men have broader shoulders?
Shoulders support larger arms which could increase boxing force
- We fight with our firsts more than other apes due to bipedalism
- Our bones in our hands and faces are more robust to withstand punching forces ⇒ reproductive competition
how does muscle change for men compared to women? (6)
- 50% more muscle mass in upper body
- 10-15% more muscle mass in lower body
- Denser, stronger bones, tendons and ligaments
- 30% greater lung volume per body mass ⇒ oxygen
- Larger heart
- Fewer white blood cells, more susceptible to infection from less energy put toward the immune system (men die at faster rates at every age)
T/F by 12 the average boy is stronger than his mother
true
when do males tend to be bigger than females?
with intense male-male competition for mates
how does fat differ in men vs women?
Men have 15-18% while women have 22-25%
- Breasts advertise fertility, nubility
- Fat provides important energy store for growing and feeding babies
what type of fat gives a rounded appearance to women’s bodies?
Subcutaneous fat
- curves of breasts, accentuates curves of hips
what type of hair are humans born with?
vellum hair covers body from birth ⇒ similar to chimps
how does vellus hair become terminal hair with puberty?
Under influence of androgens
- goes from no noticeable hair to genital hair, arm/leg hair, head hair, and other various places
what are possible uses of extra hair? (2)
- Visual signs of sexual maturity
- Retain glandular secretions (odors)
why would men need beards? (5)
- Visual signal of adult male status
- Retain glandular secretions
- Protect the face during fighting
- Exaggerate body size
- Visual signal of species identity
Eccrine sweat glands; main function?
are all over the body and excrete mainly water and salts; thermoregulation
Apocrine sweat glands; main function?
in the face, armpits, and genital area excreting complex fatty compounds ⇒ bacteria break these down and produce body odor; scent glands
during adolescence what gets clogged with appearance of zits?
sebaceous glands which often build up in the hair follicular canals
sebum
complex oily substances that makes hair waterproof (oily) ⇒ glands occur at base of hairs, eyelids, lips, nipples, labia, penis
- Exchanged during kissing
what happens to specifically females with blood production?
lining of the uterus being shed
- the ovaries produce eggs
- these are released into the fallopian tube at sexual maturity each month
- sperm swim up the tube and travel down together
- growth happens in the uterus where the baby is and lining will shed to prepare for pregnancy
what happens with sperm production for adolescent boys? Cell process?
spermatogenesis occurs via meiosis and these develop into sperm
- go from the scrotum up the tube and then into the penis where they leave the body
what differs between men and women omens voices? why?
men have lower voices than women ⇒ at adolescence both male and female voices deepen but males more than females’ males have longer folds and the male larynx is lower and vocal tract is 15% longer
why would males develop a deeper voice? (2)
- Larger individuals have longer vocal tracts
- Low pitched male voices make them sound bigger
Note: Longer vocal tracts produced lower pitches
how do vocal cords become deeper in pitch?
Increasing the length of the string or thickening the string create lower pitches
- vocal folds are between cartilage and they vibrate like guitar strings
what are males specialized for? females? what increases from puberty for both?
- males become bigger, stronger, hairier, smellier, oilier, sweatier
- Specialized for fighting and mating effort - women become fatter, curvier, hairier, smellier, oilier, bloodiers
- Specialized for parenting effort
why do we have so much greek in our scientific language?
Alexander the great and his conquests across this area
- Influenced by ideas from Aristotle, Plato, and Socrates
- All contributed to how we think about sex and gender
T/F there were gender roles in ancient Athens?
True
- gender roles were strictly determined ⇒ many of the men and women in athens were enslaved
free men’s gender roles in Athens?
- Public life
- Politics, business, war
free women’s gender roles in Athens?
- Domestic life
- Bore and raised children
- Cooked food
- Wove and made clothes
Note: Women could not vote, participate in politics, and had limited property rights
Athena parthenon
Athena the virgin was a powerful warrior goddess and had to refrain from having children ⇒ attention to reproductive roles, mothering roles, and societal warrior roles in the public life
- Female gods played very active roles
Socrates ideal regime as proposed in Platos republic? (5)
- Ruled by philosophers
- Men and women had equal rights and roles
- Both men and women serve as warriors
- Sexual relations and raising children were communal
- Breeding program ensured the production of the best offspring
Social constructionism of gender
gender roles are arbitrary and unrelated to biology
- in our society they happen to be a certain way and in other societies they may be different
- observed sex differences are result of social processes entirely
- differences in occupation and other outcomes result from discrimination
Biological determinism
gender identity results from biological factors ⇒ hormone exposure during development
- sex differences in temperament, behavior result from natural selection
- fundamental to human nature
- differences in occupation and other outcome reflect natural preferences
T/F most people reject extremes of biological determinism and social construction as vote in favor of the middle?
True
which did Descartes propose? How did it work? (anatomy?
dualism where the spirit exists independently of the body; interacts with body via the pineal gland (in the brain)
- Interested in how the body worked as a machine when machines were becoming invented more and more
- Pineal gland is more involved in circadian rhythm ⇒ what we know today
Dualism
two separate things ⇒ such as the body and the mind
dualism of sex and gender according to Descartes (2)
- Sex is an immutable essence inherent to our true selves ⇒ we see this on both sides of the political spectrum
- We are spirits living in a material world
How does Cartesianism vs evolutionary biology differ in how the body is affected by evolution?
- Cartesians focus on evolution stopping at the neck where in the head we are spiritual
- evolutionary biology focuses on how the whole body is affected by evolution
Sex
mainly what is between your legs and anatomically present
Gender
mainly what in your head
- Only humans have gender, other species do not
biological variables for gender (5)
- Chromosomal
- Gonadal
- Hormonal
- Internal organs
- External organs
female based biological gender? (5)
- XX
- Ovaries
- Estrogens
- Uterus, vagina
- Clitoris, vulva
male based biological gender? (4)
- XY
- Testes
- Androgens
- Prostate, seminal vesicle
penis, scrotum
Assigned genders
boy vs girl
gender identity
personal identification of boy/girl (etc.)
gender role
feminine/masculine
what is the biological view of the sex pathways?
- chromosomal sex
- gonads
- hormones
- brain => psychosociality => gender identity and sexual orientation
- body => bones, muscles, fat, etc.
T/F hormones act on the brain during development and continuously once born?
True
- Can affect psychosocially which can in turn affect the body
- Your brain and body are not independent ⇒ they interact
- Over development they develop a gender identity and sexual orientation
what is the biological view of the gender pathways?
- chromosomal sex
- gonads => hormones (influenced by biomedical interventions
- brain => psychosociality => gender identity, sex orientation, social experiences
- body => social experiences, psychosociality, life history changes
( influenced by biomedical interventions)
biomedical interventions
humans have learned how to manipulate our bodies through technology ⇒ synthesizing hormones, surgeries, intervention in various ways, etc.
- Hormones, gonads, etc. ⇒ affects lots of people
how does our life history change?
as hormonal effects carry on throughout the lifetime at various stages
- Psychosocially is affected by our social experience because they interact
- Our body interacts with our social experience based on how our body looks ⇒ people will interact with you differently and the body responds to that
Biological sex
mostly binary ⇒ gamete size, transmission of mitochondria
sexual identity
how someone feels about themselves and emerges from biological, technological and cultural processes
T/F many societies have non binary people?
True
- Two spirit people among some native american groups ⇒ masculine and feminine spirit
- Fa’afafine in Samoa
T/F many experience mismatch between our self-perceptions and the roles expected of our gender?
True
- Includes people who feel they are in the wrong body for their sex ⇒ continuum
- People may not be interested things that are typical for their gender role
Norms
idealistic expectations
- individuals vary and every individual is unique and differs from norms in various ways
- In evolutionary sciences, we are interested in individuals variation because variation is essential for evolution
what is the largest erogenous zone on the body?
the brain
- it influences sexual arousal (sensitive to sexual stimulation)
- learning informs most of what we do ⇒ including the ideas that have been around for 1,000s of years
where do testosterone levels spike during growth from prenatal to adulthood?
spikes in utero (16 weeks) and infants (10 weeks) and then again in adolescence around 12 years
what happens when guinea pigs are treated with testosterone while pregnant? Birds?
results in masculinized reproductive behavior of female offspring; differences in singing behavior and associated brain structures
T/F androgen exposure in utero affects gender identity expression in humans?
True most likely
where do males and females have varying overlap?
gender identity and sexual orientation
- somewhat for childhood play
what are female trait sex differences? Males?
females have more empathy usually; males typically have more physical aggression, 3D mental rotation capacity, and social dominance
T/F there are occupational differences between genders even in societies with histories of gender equality?
True
- female dominated: education, special education, school teachers, dental hygienists, nurses
- male dominated: dentists, medical doctors, airplane pilots
- some of these like dentists and doctors are closer to 50/50 now
why might women and men have different occupations (3)
- Women are discriminated against in higher status professions
- Could be consequential from division of labor in families ⇒ if men and women differ on the amount of time they spend on childcare and domestic chores
- Differences come from natural preferences or a result of what we have learned from societal norms
stabilizing selection
selection against phenotypic extremes that results in a more middle trait type ⇒ keeps populations the same
directional selection
selection toward a certain extreme phenotype compared to another
disruptive selection
the mean value of the trait is selected against in fitness and two extreme types are more common ⇒ can happen independently of sex or sex linked traits
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