Population Genetics: Why do we have different skin colors?: Crash Course Biology #14

In this episode of Crash Course Biology, we’ll learn about the ways population genetics reveals how groups of living things evolve—by comparing genetic similarities and differences. We’ll discover the most genetically diverse species of all (hint: it’s not us), find out why “race” isn’t the biologically valid category we’ve made it out to be, and learn there’s much more in our DNA that we share than that sets us apart.

Chapters:
Population Genetics 00:00
Genetic Diversity 2:34
Levels of Genetic Diversity 3:56
Melanin Variation 5:57
Clines & Ancestry 8:13
Race & Society 8:51
Review & Credits 11:32

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[fiveminutefridays]

ive been loving this whole series but this one just shows why i love Crash Course so much. The balance y'all have in this script with the objectivity of science vs the subjectivity of culture, and the matter-of-fact.casual tone of a fun education channel while still being respectful of a heavy topic like racial inequality - masterclass in effective communication

[Lyoko]

Oh my god, I haven’t watched Crash Course in a while but I love this new host, Dr. Sammy! So glad to see more people like me as PhDs, communicating science, dialect ‘n all. I’m glad that Crash Course is making room for everyone to shine (and shed light on topics like this) ✨

[Reilaos]

The Skin color map leaves out the really interesting exception of latitude=> skin color corelation: the Inuit and other similar tribes!

Diets that include regular use of blubber supplement vitamin D, meaning there wasn't the same selective pressure for lighter skin. Thus, they remained darker despite being further north!

[curiosityman]

The host here is the coolest guy I have ever seen. Hope to see more of him.

[kateisblue]

I love how much understanding evolution and how species diverge and intermingle can help understand so many other concepts!

-Linguistics and language diversification 🗣💬🗯
-Social psychology and idea spread and development, 👥️️💡
-medicine, virology and microevolution🩺⚕️🦠
-psychiatry, neurology and stuff like CBT 🧠💭
-chemistry, physics and entropy even! 🧪⚛️

The way evolution works is really similar to processes EVERYWHERE in the universe so it's super useful to understand :)

[BrotherExperimentus]

Just found you. Instant subscriber. Young, well-spoken, intelligent, empathetic, unbiased, well-educated, and good looking, doctor, you have it all. I am impressed, beyond words I would say, but evidently that would be an untruth. I am old but have always had a fascination with humanity, its past, its evolution, and its future. I hope one day to be a doctor myself to contribute to our understanding of ourselves and hopefully to bring forth the insight that you have here into how our differences make us the same. Until today, I was not aware of the small percentage of genetic variation within the human race. I have also learned from you the reason we utilize the word "race" in a non-scientific context to describe minor, inconsequential differences between us, often in a manner that is demeaning and counterproductive. I wish that racism was not a thing, that we could all work together to heal our perceived differences for a better future. Your work here to educate others is a stepping stone to that end, and I intend to recommend others to watch you to learn to be better people, human-beings, if they will listen and understand. A big expectation, but you are certainly giving me hope for that future being so easy to listen to, the way you lay out the facts in a way anyone can understand. Thank you.

[aslightlysavageburrito]

Love the implication that the British person in the intro would refer to Galarian Slowpoke! Fantastic reference there. <3

[herebecause]

Thank you Thought Bubble for the burning skeleton 😆 and thank you for a very thoughtful presentation! The biracial Chinese/Irish example is a mic drop. It's so bizarre that some forms still limit you to one "race"

[chaunceychaney]

honestly im trying to get my phd and host a crash course playlist lol seems soo fun!

[StrayVagabond]

Your cadence and diction reminds me of levar Burton

[gypsydonovan]

I'd say the internet is part of the rise in doppelgangers as well. For 2 million years of human history, we were extremely limited in how many people we saw, and those people were mostly regional.

Even 200 years ago it wouldn't be unusual for people across the world to have never seen someone of another race in person. 400 years ago the majority of people had never seen it.


For the last 30 years we've been able to see and communicate with people all over the world. If I have a friend in Seattle who moves to Argentina & she sees a woman who looks just like me - I'm going to hear about it, probably get a photo. She's probably going to approach my doppelganger & tell her about me. For most of human history, we'd have lived our lives on separate continents without even knowing about the other.

Then there's the facial recognition software of the last decade. I'm tagging a friend in a photo & some near-twin in Indonesia gets suggested.

I'm not doubting the genetic component, that may be the reason for the doppelgangers. I just think it's the mass communication, the internet & particularly social media that are how we know these doppelgangers exist.

[PrinzessinMurx]

Very very well made video and channel. You are so likeable and you explain so damn good, I wish I had your channel when I was in school 20 years ago

[baratobenito]

growing up christian was very harmful for my education on how this stuff worked. this was never explained but we were just supposed to believe all humans came from two white people. I love your vids!

[radagastwiz]

The throwback to Goatee Hank in the thumbnail is quite the deep cut. Especially since Present Hank is sporting a mustache.

[Jadesmorot]

Amazing, as always, and a fantastic host to boot! ❤

[littledreamerrem]

Okay, I am now in love with Dr. Sammy. Excuse me while I go raid some research paper databases.

[Silverfish]

Mic Drop!! Make science fabulous every DAY

[abemisty]

Hi how are you and this video was so amazing keep up the good work

[tonysantiago]

Loved your style of communicating this message, ❤

[ingvar]

Very interesting! Looking forward to the next episode!