Gender, Sex, & Sexuality: What’s the Difference?: Crash Course Biology

many people in societies think of sex as

split across two tidy boxes male and

female but life in all of its glorious

complexity tells another story like

there are these fish called Australian

goes that all start out as female but

later some start producing sperm while

still having cells that can become eggs

so in one lifetime they can be female

then male and female then female again

it's not a static either or thing and

that's just the start of life's binary

busting rainbow there's a plant called

tropical Ginger that switches between

male and female every

afternoon many kangaroo rats have both a

vagina and a penis and forget male or

female the split Gill fungus has over

20,000 Sexes and the evidence for sex as

a Continuum isn't just found in fish and

fungi but in us too hi I'm Dr Sammy your

friendly neighborhood entomologist and

this is crash course biology and this is

a singular theme song that also defies

categories hit

[Music]

it this episode we're talking about sex

gender and sexuality and the first thing

you need to know is they're not all the

same thing gender for example is totally

unique to humans it refers to a person's

inner sense of being a man a woman some

other gender or no gender at all and

it's about a person's identity and how

it's expressed in relation to Social and

cultural norms and different cultures

have different ideas about what it means

to be feminine or masculine or how many

genders there are like some Native

American groups have long recognized a

third gender which is sometimes called

two spirit the boogies people of sui

recognize five genders including one

that transcends male or female and many

Western cultures today are widening

their understanding to include people

who are non-binary trans and more so

yeah sex and gender not the same thing

sex isn't an identity but rather a way

of categorizing life based on a range of

traits including what reproductive cells

an individual makes this can seem

confusing because we do tend to assign

someone a sex and a gender when they're

born like when we say it's a boy or it's

a girl based on outward sex indicators

like genitals we're assigning a sex but

we tend to bring with that a suite of

cultural expectations that are part of

gender like the specific colors or gifts

that are typically brought to gender

reveal parties and sexuality describes

who someone is sexually attracted to if

anyone and just like sex and gender

sexuality exists on a Continuum but

we'll get to that later for now let's

get into biological sex which like I

mentioned is often tied to reproductive

cells called gametes you see the ability

to reproduce is one of the Hallmarks of

life and life has evolved a lot of ways

to do it with diverse bodies and

behaviors to match though for a long

time time it seemed like this was

relatively simple see there are often

two different forms of the same animal

one has small simple gametes that don't

require a lot of energy to produce

called sperm and the other has a smaller

number of larger gametes that are

comparatively expensive to produce which

are called eggs the individual that

produces the sperm is called the male

and the individual that produces the egg

is the female this holds true for a fair

number of organisms but the more you

look the more complex it gets like for

example it is not super rare for one

organism to contain both sperm and eggs

but the sperm egg dichotomy is common

enough among life on Earth and useful

enough that it's helped us classify all

sorts of life like take genko trees for

example when we talk about male and

female genos we don't call it a male

tree because it's taller and has more

body

hair that would be an odd tree indeed

but no we call it a male tree because it

produces pollen which is tree sperm and

not ovules which are tree eggs sometimes

we talk about sex in terms of ecology

and species-wide attributes but it's

also important to consider that when you

drill down into individuals we find

again that nature will make any harsh

lines fuzzy like if you're talking about

individual humans you can't just boil it

down to sperm and eggs because lots of

people don't produce either and there

are also a ton of other important traits

Beyond gametes like biologists also

consider several physical traits such as

Anatomy

chromosomes and hormones when

identifying Sexes and when biologists

study sex differences they often look at

averages for a sex average hormone

levels average Anatomy but those traits

can overlap let's look at chromosomes

for example more specifically our 23rd

pair of chromosomes called alomes in

humans and many other animals alomes

come in two versions the larger and

information Rich X chromosome or the

smaller y most people inherit one ome

from the egg that made them and one from

the sperm and each one holds genetic

instructions for making proteins which

are like the bodies clay for building

organs an XX person often has organs

called ovaries that make eggs plus a

vagina vulva and uterus an XY person

often has testes that make sperm along

with the penis ovaries and testies

secrete different blends of hormones so

XX bodies usually have higher levels of

estrogen while XY bodies usually have

more androgens such as testosterone

these hormones shape other physical

features that we tend to think of as

female or male like breasts or hairy

chests but I'm saying people with XX

chromosomes not women and XY people not

men because man and woman refer to a

person's gender which as we discussed

earlier is different from sex someone

with XX chromosomes isn't always a woman

and someone with XY chromosomes isn't

always a man plus when it comes to sex

what's going on in the soms is just the

beginning you see some XX or XY people

have Gene variants that cause a diverse

blend of hormones or anatomy and this

can result in the physical expression of

a different sex than the one that their

chromosomes would indicate and some

people inherit three alomes so they're

xxy or XXX or XY Y which can lead to a

bunch of different sexual features and

then some people are x0 with just one

alome but there's nobody out there who's

y zero because we all need at least one

X chromosome to live there are important

genes in there that help the brain

develop these variations along the sex

Continuum are called differences in sex

development or Some people prefer the

term interex and a person is about as

likely to have these Gene variations as

they are to have red hair they're

present in about one in every 100 people

so chances are you probably met at least

somebody with one of these differences

even if you didn't know it even if they

themselves didn't know it there aren't

always outward signs like if an XY

person inherits a variant of the amh

gene they may develop organs often found

in XX people so they might have a uterus

and Fallopian tubes while also having a

penis testes and levels of the hormone

testosterone that would be normal for an

XY person or if an XY person has a

variant of the AR Gene their body

ignores testosterone a condition called

Androgen in Sensitivity Syndrome often

they have a vagina and breasts and no

uterus and sometimes a testicle in

inside their bodies so yeah sex is way

more complex than male or female it

isn't determined by any single trait and

it's not turned on or off by any single

Gene it's an assortment of overlapping

interactions between chromosomes

hormones and genes so that's gender and

sex neither of which can be put into

nice tidy Little Boxes now let's take

some time to talk about sexuality which

like I mentioned earlier describes who

someone is sexually attracted to if

anyone just like sex and gender

sexuality doesn't fit neatly in distinct

boxes someone can be attracted to the

same gender uh another gender both their

own and other genders all genders or

none at all for some attraction stays

steady for life for others it's more

fluid all of this is normal and diverse

sexuality is nothing new attraction to

the same gender for example has been

written about in ancient texts from

China Japan India Greece and more across

cultures today it's experienced by about

5% of people that number varies a bit

from place to place depending on

cultural attitudes and the question

that's being asked in the surveys like

it's more common for people to report

that they've had at least one same

gender experience than to say that they

are exclusively attracted to the same

gender but either way diverse sexuality

is a very normal very human trait and

while we don't need to look to other

animals to justify human sexuality

life's diversity does help us understand

our own let's head over to the thought

bu it's 183 4 and German school teacher

August Kelch can't believe his eyes in a

forest in Poland he has just stumbled on

two male doodle Bugs well doodling each

other keep in mind the word homosexual

didn't exist yet in German or in English

so you can imagine Kel's surprise

especially considering people attracted

to the same sex were considered

unnatural at the time nonetheless Kelch

described what he'd seen and shared it

with the scientific Community the

reception was not great a mix of moral

outrage disbelief and disgust some tried

to explain it away arguing that one bug

was actually female or that both bugs

were confused I wouldn't be surprised if

someone tried to claim that they were

just really good friends or roommates

but other scientists came forward with

their own sightings of male doodle Bugs

doing the doodle and then in the 1890s

another scientist argued that it was

natural and the males were choosing to

mate with each other

sparking more criticism eventually the

doodle bug debate faded but then same

sex activity popped up again in Penguins

big horn sheep giraffes and the same

questions simmered each time questions

that were never really about just doodle

Bugs if samesex activity is truly

unnatural as many people had claimed

well why is it found again and again in

nature thanks thought bubble since the

doodle Bugs scientists have observed

over 1,000 different species mating and

even parenting with the same sex for

some species these are oneoff flings but

others show a strong preference for

samex partners like about 8% of male

sheep aren't interested in sex with

females and exclusively prefer other

males and all of this raises interesting

questions about Evolution like if the

evolutionary point of sex is making more

life why would same sex mating be a

thing at all a common thing even in

whales koalas geese even Beatles

and the answer is we don't exactly know

yet but there are a few different ideas

one idea is that organisms who will mate

with anyone mate more overall increasing

their chances of having Offspring so

maybe there's an evolutionary advantage

to just being a little thirsty another

idea is that samesex mating reduces

competition and helps social animals

form close bonds best way to not have

haters make them your lovers like male

Dolphins often pair together having sex

with each other multiple times a day

inviting the occasional female to join

in I'm thinking they deleted that scene

from sharktale and then there are

bonobos Humanity's closest relatives

among them same-sex mating keeps the

vibe of the whole group peaceful in fact

female bonobos have more sex with each

other than they do with males for some

species same-sex sexuality might

actually help survival and for the rest

is definitely not hurting them in the

end sexuality is just one aspect of the

incredible A diversity built into life

diversity that underpins healthy robust

populations after all like we said way

back in episode one life is the most

fascinating thing to ever happen on this

planet biology sometimes gives us broad

categories that are useful overall but

when it's something as complex and

gigantic as life it's not going to be

that simple and when you start talking

about human life and our societies and

cultures well then it's going to get

really fun we are like light through a

prism each of us a fractal beautiful in

our own right but bound together in

life's Kaleidoscope of color we know so

much about ourselves and yet we're all

still learning but here's one thing that

we like to say around here imagine

others complexly and that means looking

deep thinking hard being kind and

recognizing the reality of the beautiful

variety of Human Experience next time

we'll take a deep dive into animal

behavior I'll see you then peace this

series was produced in collaboration

with hhmi biointeractive if you're an

educator visit biointeractive.org g/c

crashcourse for classroom resources and

professional development related to the

topics covered in this course thanks for

watching this episode of Crash Course

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in Indianapolis Indiana and was made

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