Foreword by Susan Eckert (teacher)
This post is written as a collaboration between student and teacher. The topics in this post are challenging and complex. As a teacher, I have been dwelling on the genetics of race for years now and always felt that I did not do the topic justice in the classroom. I see this post as an opportunity to work with a student and make some progress on how to more effectively teach my students about the biological basis of race (beyond just saying there is none). All science in this post and the entire blog is supported by evidence. However, this post, like many on the blog, gives both student and teacher the space to discuss the intersection of science and morality. Science is a distinctly human effort to understand the natural world and it does not exist in a vacuum--history and context matters.
The Biology of Melanin by Shannon Huhn (student)
Did you know that your skin is the largest organ of your body, your first line of defense against pathogens and your primary defense against the sun's damaging rays thanks to melanin? Melanin is an invaluable pigment that is found in all humans (and in many other organisms)--its key functions that protect us from Earth’s harsh conditions are necessary for our survival. For example, did you know that the melanin you produce protects you every time you step outside? One of melanin’s prime functions is to protect the epidermis (the top layer of your skin) from the ultraviolet (UV) radiation from the sun. Melanocytes, cells where melanin is produced, can absorb UVA and UVB rays that can be harmful to your skin and increase the risk of skin cancer by damaging DNA. This is why your skin gets darker during the summer--your body produces more melanin in response to increased sun exposure.The classic "farmer's tan" which results from the skin responding to increased UV exposure by producing more melanin. Source |
Different properties of melanin have been influenced by human evolution. For example, two different types of melanin have been the result of evolution. Eumelanin and pheomelanin can influence how dark or light your skin tone is--those with lighter skin have higher amounts of pheomelanin, and those with darker skin have higher amounts of eumelanin. Interestingly, we all have roughly the same amount of melanocytes and what differs is the amount and type of melanin the melanocytes produce. Since each person has different levels of these two types of melanin based on genetics/ancestry and the environment, there is a large variety of skin tones across the globe and in the US. Here is a TED talk on the beautiful variation of skin color among humans.
Variation in skin color in a family. Source |
Black Lives Matters protestors in NYC on June 9th, 2020. Source |
Genetics and Race by Susan Eckert (teacher)
I'm going to get straight to the point: there is no biological basis of race. It is a social construct and my primary goal is to provide enough knowledge about the variation of the human genome to allow the reader to easily refute those that try to use science to promote an agenda of racist ideology. The idea of a biological basis for race has a long and dark history based on biological determinism, which led to eugenics, the justification of genocide, colonialism, and slavery. When I started college in 1990, I knew that I wanted to pursue a career in genetics. My freshman seminar was about eugenics and we read Stephen Jay Gould's Mismeasure of Man. Stephen Jay Gould was a paleontologist, evolutionary biologist, historian of science and a well-known science communicator. The book forcefully criticizes against biological determinism that used skull measurements, known as craniometry, and psychological testing, and then assigning worth to an individual based on these measurements. There has been some criticism about the book's data analysis but the premise of the book I stand behind.Craniometry. Source |
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So what does this all mean for the classroom? How do I teach about race when we get to the genetics unit in AP Bio? Should I even talk about it at all? It's not a topic that most biology textbooks tackle and it's not specifically in my curriculum. Genetic variation, however, is and that is why I have gone there, although not at the level I would like, and why I will continue to explore the topic with my students. The general population holds a lot of misconceptions about the biology of human variation and that of course includes students and teachers as well. Some teachers are tackling it head on. And resources to help teachers navigate the topic in the classroom do exist.
It's crucial to stress that even though there is no evidence for a biological basis for race, we can't simply say we don't see color and act as if the social construct of race and racial identity do not matter. Instead, we should understand the role evolution and biogeography play in human genetic variation, fight racism with scientific knowledge, commit to ending racial injustice, and learn about and celebrate human genetic and cultural diversity.
Addendum: There are many hyperlinks in this blog post. The articles I (Susan) have linked to below are the ones I recommend the most.
An excellent blog post that tackles the genetics of human variation in more detail
An article in the journal Nature Genetics that dives much deeper into the science
An article in The Atlantic that focuses on the difficulty of teaching race in HS biology classes
If you have questions or concerns about the content of this post, please email Susan Eckert at seckert@montclair.k12.nj.us or suseckert@gmail.com
An excellent blog post that tackles the genetics of human variation in more detail
An article in the journal Nature Genetics that dives much deeper into the science
An article in The Atlantic that focuses on the difficulty of teaching race in HS biology classes
If you have questions or concerns about the content of this post, please email Susan Eckert at seckert@montclair.k12.nj.us or suseckert@gmail.com
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