Although the nearly hairless bodies of humans stand out like a forelock among other primates, our nudity is not unique to the mammalian world. Dolphins and whales are naked, says biological anthropologist Tina Lasisi of the University of Southern California in Los Angeles. There are naked mole rats. “Elephants, depending on how you look at them, are a little bit bare,” she says. “But we’re the only weirdos that are naked except for our heads.”
Our species traded much of our body hair for more sweat glands, an evolutionary adaptation that helps us regulate body heat more efficiently. But what about another uniquely human characteristic? We are the only animals known to have very curly hair, like that seen on many people of African descent. Lasisi wants to know why and how it came to be.
For decades, traits that have been associated with racial categories, such as skin pigmentation and hair texture, have been poorly studied or ignored among anthropologists, Lasisi says. Much of the study of human biological variation was abandoned after the post-World War II backlash against eugenics, a racist field that was born out of the idea that humanity could be bettered if it were allowed to selectively reproduce those deemed who had desirable traits. Since then, research on human variation has largely focused on traits that are not overtly racialized, such as lactose intolerance and adaptations to high altitudes.
But studying all forms of human variation is crucial to understanding the evolution of our species, says Lasisi. Studying variation in a way that normalizes rather than muffles or paints differences in a bad light is key not only to correcting anthropology’s damaging legacy, but also to sound, socially responsible, and ethical science, she says.
Lasisi discovered biological anthropology when he was an undergraduate student at Cambridge University. As a black person who spent many of his formative years among whites in the Netherlands, he was always conscious of skin color. He vividly recalls learning that human skin pigmentation evolved as an adaptation to ultraviolet radiation, research pioneered by Penn State anthropologist Nina Jablonski, who would later become Lasisi’s top adviser. “It’s like a lightbulb went off in my head,” Lasisi says, making her wonder, “What else can be explained by evolution?”
His interest in the origins of curly hair grew in part as an effort to understand his own locks. “Research is the search for myself,” says Lasisi. But when he started, there wasn’t much science to examine and methodologies for measuring hair texture were either unreliable or ineffective.
As part of his Ph.D. research, Lasisi worked with a team of anthropologists, thermal engineers, and physiologists to study how curly hair might have helped our bipedal ancestors in the hot, dry African savannah.
The team placed a variety of wigs made from human hair on heat-sensitive models and measured heat transfer in different environments. In dry environments, curly hair, especially frizzy hair, protects the scalp from solar radiation and releases more heat from the head than straight hair. Lasisi speculates that the increased amount of air space within curly hair is what does the trick.
To support their efforts and support future hair research, Lasisi developed an improved and standardized way of measuring hair curvature and cross-sectional shape. The technique involves segmenting, washing and taking pictures of strands of hair and then running the images through an open source computer program she created.
Measuring these characteristics on a continuous spectrum (much like we do with height, for example), he argues, is a better way to study hair texture than the traditional practice of classifying hair into discrete categories, such as straight, wavy, or curly. . These discrete categories are not standardized among experts and can become subjective, she says. They also obscure the immense variation that exists, even on a single person’s head, and especially among curly hair.
Lasisi is doing highly technical work that hasn’t been part of the conversation, says Robin Nelson, a biological anthropologist at Arizona State University in Tempe. “Before Tina, very few people worked on hair texture in the same way.”
Lasisi will bring this experience to the University of Michigan at Ann Arbor as an assistant professor in 2023, where she will continue her studies on human variation.
Lasisi wants everyone to be included in conversations about what makes humans human. She has appeared on the podcast. Feeling curious with Jonathan Van Ness (of queer eye fame). He also hosts a PBS digital show on human evolutionary biology called Because I’m so?that she helps conceptualize and write.
Additionally, Lasisi has cultivated a community of curious science seekers on Twitter, Instagram, and TikTok. Through short-form videos marked by his trademark wit and humor, such as his “Melanin March” series or “Darwin’s Greatest Hits Against White Supremacy,” Lasisi educates thousands of followers on human variation, how to talk about race and ethnicity from an anthropological perspective. perspective and much more. She even gives would-be anthropologists career advice and behind-the-scenes glimpses of life in academia. Two-way discussions allow you to learn from his audience, which he calls his “little focus groups.”
Lasisi hopes that her research and outreach will inspire and provide a useful framework for more nuanced discussions of race, ethnicity, ancestry, and human diversity, and that her visibility as a Black anthropologist will encourage other people of color to ask questions that matter to them. “I want to put enough information out into the world, and [have] there are enough people in the world who know that information,” he says, “so that we can see human variation for how beautiful and magnificent and complex it is.”
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