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Gender, Sex, & Sexuality: What’s the Difference?: Crash Course Biology #48
YouTube: | https://youtube.com/watch?v=P8scg_XAgZQ |
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Duration: | 13:37 |
Uploaded: | 2024-06-25 |
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MLA Full: | "Gender, Sex, & Sexuality: What’s the Difference?: Crash Course Biology #48." YouTube, uploaded by CrashCourse, 25 June 2024, www.youtube.com/watch?v=P8scg_XAgZQ. |
MLA Inline: | (CrashCourse, 2024) |
APA Full: | CrashCourse. (2024, June 25). Gender, Sex, & Sexuality: What’s the Difference?: Crash Course Biology #48 [Video]. YouTube. https://youtube.com/watch?v=P8scg_XAgZQ |
APA Inline: | (CrashCourse, 2024) |
Chicago Full: |
CrashCourse, "Gender, Sex, & Sexuality: What’s the Difference?: Crash Course Biology #48.", June 25, 2024, YouTube, 13:37, https://youtube.com/watch?v=P8scg_XAgZQ. |
We tend to think life fits in two tidy categories: male or female, XX or XY. But it’s so much more diverse and complicated! In this episode of Crash Course Biology, we’ll discover sex and sexuality as a continuum across life. We’ll learn why humans are the only species with gender, and why same-sex mating is more common than you might think.
Introduction: Sex & Gender in Humans 00:00
How Sex and Gender are different 01:15
Sex development 04:42
Differences in sex development 06:02
What is sexuality 07:46
Non-human diversity in sexuality 08:50
Review & Credits 12:12
This series was produced in collaboration with HHMI BioInteractive, committed to empowering educators and inspiring students with engaging, accessible, and quality classroom resources. Visit https://BioInteractive.org/CrashCourse for more information.
Check out our Biology playlist here: https://www.youtube.com/playlist?list=PL8dPuuaLjXtPW_ofbxdHNciuLoTRLPMgB
Watch this series in Spanish on our Crash Course en Español channel here: https://www.youtube.com/playlist?list=PLkcbA0DkuFjWQZzjwF6w_gUrE_5_d3vd3
Sources: https://docs.google.com/document/d/1GLDtAXE6ekg4Chk2qN3TYbNt0pJbyaHqTqRd6QY8pd4/edit?usp=sharing
***
Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse
Thanks to the following patrons for their generous monthly contributions that help keep Crash Course free for everyone forever:
Leah H., David Fanska, Andrew Woods, DL Singfield, Ken Davidian, Stephen Akuffo, Toni Miles, Steve Segreto, Kyle & Katherine Callahan, Laurel Stevens, Burt Humburg, Perry Joyce, Scott Harrison, Mark & Susan Billian, Alan Bridgeman, Breanna Bosso, Matt Curls, Jennifer Killen, Jon Allen, Sarah & Nathan Catchings, team dorsey, Bernardo Garza, Trevin Beattie, Eric Koslow, Indija-ka Siriwardena, Jason Rostoker, Siobhán, Ken Penttinen, Nathan Taylor, Barrett & Laura Nuzum, Les Aker, William McGraw, Vaso, ClareG, Rizwan Kassim, Constance Urist, Alex Hackman, Pineapples of Solidarity, Katie Dean, Stephen McCandless, Wai Jack Sin, Ian Dundore, Caleb Weeks
__
Want to find Crash Course elsewhere on the internet?
Instagram - https://www.instagram.com/thecrashcourse/
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
CC Kids: http://www.youtube.com/crashcoursekids
Introduction: Sex & Gender in Humans 00:00
How Sex and Gender are different 01:15
Sex development 04:42
Differences in sex development 06:02
What is sexuality 07:46
Non-human diversity in sexuality 08:50
Review & Credits 12:12
This series was produced in collaboration with HHMI BioInteractive, committed to empowering educators and inspiring students with engaging, accessible, and quality classroom resources. Visit https://BioInteractive.org/CrashCourse for more information.
Check out our Biology playlist here: https://www.youtube.com/playlist?list=PL8dPuuaLjXtPW_ofbxdHNciuLoTRLPMgB
Watch this series in Spanish on our Crash Course en Español channel here: https://www.youtube.com/playlist?list=PLkcbA0DkuFjWQZzjwF6w_gUrE_5_d3vd3
Sources: https://docs.google.com/document/d/1GLDtAXE6ekg4Chk2qN3TYbNt0pJbyaHqTqRd6QY8pd4/edit?usp=sharing
***
Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse
Thanks to the following patrons for their generous monthly contributions that help keep Crash Course free for everyone forever:
Leah H., David Fanska, Andrew Woods, DL Singfield, Ken Davidian, Stephen Akuffo, Toni Miles, Steve Segreto, Kyle & Katherine Callahan, Laurel Stevens, Burt Humburg, Perry Joyce, Scott Harrison, Mark & Susan Billian, Alan Bridgeman, Breanna Bosso, Matt Curls, Jennifer Killen, Jon Allen, Sarah & Nathan Catchings, team dorsey, Bernardo Garza, Trevin Beattie, Eric Koslow, Indija-ka Siriwardena, Jason Rostoker, Siobhán, Ken Penttinen, Nathan Taylor, Barrett & Laura Nuzum, Les Aker, William McGraw, Vaso, ClareG, Rizwan Kassim, Constance Urist, Alex Hackman, Pineapples of Solidarity, Katie Dean, Stephen McCandless, Wai Jack Sin, Ian Dundore, Caleb Weeks
__
Want to find Crash Course elsewhere on the internet?
Instagram - https://www.instagram.com/thecrashcourse/
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
CC Kids: http://www.youtube.com/crashcoursekids
Many people and 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 gobies that all start out as females. 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 twenty thousand 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 IT!! [THEME MUSIC] 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. 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 Bugis people of Sulawesi 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 and 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, 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, 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 Ginkgo trees for example. When we talk about “male and female ginkgos,” 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 line 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 allosomes. In humans and many other animals, allosomes come in two versions: the larger and information-rich X chromosome or the smaller Y.
Most people inherit one allosome from the egg that made them, and one from the sperm. And each one holds genetic instructions for making proteins, which are like the body’s 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 a penis. Ovaries and testes 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; someone with XY chromosomes isn’t always a man. Plus, when it comes to sex, what’s going on in the ‘somes 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 their chromosomes would indicate. And some people inherit three allosomes: so they’re XXY, XXX, or XYY, which can lead to a bunch of different sexual features.
And then some people are X0, with just the one allosome. But there’s nobody out there who’s Y0, 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 intersex. 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 one hundred people. So chances are, you’ve 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 Insensitivity Syndrome. Often, they have a vagina and breasts, and no uterus, and sometimes a testicle 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, 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 five percent of people.
That number varies a bit from place to place depending on cultural attitudes and the question that’s being asked in surveys. Like, it’s more common for people to report they’ve had at least one same-gender experience than to say that they’re 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 Bubble… It’s 1834. And German schoolteacher August Kelch can’t believe his eyes.
In a forest in Poland, he has just stumbled on two male doodlebugs…well… doodling each other. Keep in mind, the word “homosexual” didn’t exist yet, in German or in English, so you can imagine Kelch’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 one bug was actually female. Or that both bugs were confused. I wouldn’t be surprised if someone tried to claim they were just “really good friends” or “roommates.” But other scientists came forward with their own sightings of male doodlebugs doin’ 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 doodlebug debate faded. But then, same-sex activity popped up again in penguins.
Bighorn sheep. Giraffes. And the same questions simmered each time—questions that were never really just about doodlebugs.
If same-sex activity is truly “unnatural,” as many people claimed, well, why is it found again and again in nature? Thanks Thought Bubble! Since the doodlebugs, scientists have observed over one thousand different species mating and even parenting with the same sex.
For some species, these are one-off flings. But others show a strong preference for same-sex partners. Like, about eight percent 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 beetles!
And the answer is…we don’t exactly know yet. But there are a few different ideas. One idea is that organisms who’ll 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 same-sex mating reduces competition and helps social animals form close bonds. Best way to not have haters?
Make ‘em your lovers. Like, male dolphins often pair off together, having sex with each other multiple times a day and inviting the occasional female to join in – I’m thinking they deleted that scene from Shark Tale. 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, it’s definitely not hurting them. In the end, sexuality is just one aspect of the incredible 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 are all still learning, but here’s one thing 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/Crashcourse for classroom resources and professional development related to the topics covered in this course.
Thanks for watching this episode of Crash Course Biology, which was filmed at our studio in Indianapolis, Indiana, and was made with the help of all these nice people. If you want to help keep Crash Course free for everyone, forever, you can join our community on Patreon.
Like, there are these fish called Australian gobies that all start out as females. 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 twenty thousand 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 IT!! [THEME MUSIC] 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. 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 Bugis people of Sulawesi 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 and 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, 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, 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 Ginkgo trees for example. When we talk about “male and female ginkgos,” 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 line 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 allosomes. In humans and many other animals, allosomes come in two versions: the larger and information-rich X chromosome or the smaller Y.
Most people inherit one allosome from the egg that made them, and one from the sperm. And each one holds genetic instructions for making proteins, which are like the body’s 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 a penis. Ovaries and testes 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; someone with XY chromosomes isn’t always a man. Plus, when it comes to sex, what’s going on in the ‘somes 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 their chromosomes would indicate. And some people inherit three allosomes: so they’re XXY, XXX, or XYY, which can lead to a bunch of different sexual features.
And then some people are X0, with just the one allosome. But there’s nobody out there who’s Y0, 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 intersex. 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 one hundred people. So chances are, you’ve 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 Insensitivity Syndrome. Often, they have a vagina and breasts, and no uterus, and sometimes a testicle 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, 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 five percent of people.
That number varies a bit from place to place depending on cultural attitudes and the question that’s being asked in surveys. Like, it’s more common for people to report they’ve had at least one same-gender experience than to say that they’re 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 Bubble… It’s 1834. And German schoolteacher August Kelch can’t believe his eyes.
In a forest in Poland, he has just stumbled on two male doodlebugs…well… doodling each other. Keep in mind, the word “homosexual” didn’t exist yet, in German or in English, so you can imagine Kelch’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 one bug was actually female. Or that both bugs were confused. I wouldn’t be surprised if someone tried to claim they were just “really good friends” or “roommates.” But other scientists came forward with their own sightings of male doodlebugs doin’ 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 doodlebug debate faded. But then, same-sex activity popped up again in penguins.
Bighorn sheep. Giraffes. And the same questions simmered each time—questions that were never really just about doodlebugs.
If same-sex activity is truly “unnatural,” as many people claimed, well, why is it found again and again in nature? Thanks Thought Bubble! Since the doodlebugs, scientists have observed over one thousand different species mating and even parenting with the same sex.
For some species, these are one-off flings. But others show a strong preference for same-sex partners. Like, about eight percent 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 beetles!
And the answer is…we don’t exactly know yet. But there are a few different ideas. One idea is that organisms who’ll 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 same-sex mating reduces competition and helps social animals form close bonds. Best way to not have haters?
Make ‘em your lovers. Like, male dolphins often pair off together, having sex with each other multiple times a day and inviting the occasional female to join in – I’m thinking they deleted that scene from Shark Tale. 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, it’s definitely not hurting them. In the end, sexuality is just one aspect of the incredible 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 are all still learning, but here’s one thing 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/Crashcourse for classroom resources and professional development related to the topics covered in this course.
Thanks for watching this episode of Crash Course Biology, which was filmed at our studio in Indianapolis, Indiana, and was made with the help of all these nice people. If you want to help keep Crash Course free for everyone, forever, you can join our community on Patreon.