Podcast Summary
A Passionate Biological Anthropologist's Journey into Melaninology: Dr. Tina Lassisi, an expert in melaninology, discusses her research on scalp hair morphology and her experiences as the first Black PhD graduate in anthropology from Penn State, inspiring future generations.
Dr. Tina Lassisi, a biological anthropologist and soon-to-be assistant professor, shares her passion for the study of melaninology, or the biological pigment that determines skin color. With a background in biological anthropology from Cambridge and a PhD from Penn State, Dr. Lassisi is an expert in her field and has faced challenges as the first Black student to graduate with a PhD in anthropology from Penn State. Her research focuses on scalp hair morphology, and she shares her journey of discovering this field of study through her experiences growing up between cultures and her fascination with the Cambridge English dictionary. Her upcoming lab at the University of Michigan promises to continue exploring the complexities of melanin and its significance in human biology.
Correlation between UV radiation and skin color: Skin color and hair texture are determined by geographical location and environmental conditions, specifically UV radiation, not race.
Human traits, such as skin color and hair texture, are not determined by race but rather by geographical location and the adaptation to the environmental conditions, specifically UV radiation. The speaker, a Black woman who initially thought she would study cultural anthropology but ended up focusing on biological anthropology due to her curiosity about her own hair, described her eye-opening experience in a lecture where she saw a map of UV radiation distribution and skin color around the world. This map showed that there is a correlation between the intensity of solar radiation and the distribution of skin color. For instance, populations closer to the equator, where there is higher UV radiation, tend to have darker skin, while those further away have lighter skin. However, there are exceptions, such as high-altitude regions and populations with dark skin despite being far from the equator. This discovery challenged the simplistic notion of race and human variation and led the speaker on a decade-long journey to understand the biological basis of hair texture.
Challenging our understanding of human diversity through anthropological research: Anthropological research, such as Dr. Nina Jablonski's work with Dr. Lassisi, challenges simplistic categorization of people based on skin color and encourages considering historical and evolutionary context of differences. Understanding impact on health and reproduction crucial for ongoing evolution.
Our understanding of human diversity, as shaped by our social constructs of race and ethnicity, can be challenged and expanded through anthropological research. Dr. Nina Jablonski's work, in collaboration with Dr. Lassisi, has shown that human skin color variation is a complex result of evolution and environmental factors. This research challenges the simplistic categorization of people based on skin color and encourages us to consider the historical and evolutionary context of these differences. Moreover, as humans continue to move and adapt to new environments, understanding the impact on our health and reproduction is crucial for our ongoing evolution. Ultimately, evolution is a process of natural selection that favors those who can reproduce successfully, regardless of cultural or personal factors.
Understanding Melanin: The Complex Component of Skin Tone and UV Protection: Melanin, a complex pigment, plays a crucial role in our bodies by balancing sun exposure for vitamin D production and UV radiation protection. Skin color and melanin production have evolved to optimize this balance, but modern lifestyles can lead to vitamin D deficiency. Ensure adequate vitamin D intake through sunlight or supplements for optimal health.
Humans have a delicate balance between sun exposure for vitamin D production and protection from harmful UV radiation. Melanin, the pigment responsible for skin color, plays a role in this balance by absorbing UV radiation. Humans produce two types of melanin, eumelanin (brown or black) and pheomelanin (orange-yellow-reddish), which contribute to various skin tones and hair colors. While melanin's exact chemical structure is not yet fully understood, it's clear that it's a complex and essential component of our bodies. Vitamin D, produced in response to UVB radiation, is vital for our health, but too much UV radiation can damage folate, an essential nutrient for healthy pregnancies. Therefore, our skin color and the amount of melanin we produce have evolved to optimize our exposure to sunlight for vitamin D production while minimizing damage from harmful UV radiation. However, in today's world, many people don't get enough sunlight, leading to vitamin D deficiency. This deficiency can result in various health issues, including fatigue, hair loss, and even increased susceptibility to COVID-19 infections. Therefore, it's essential to ensure we get enough vitamin D, either through sunlight or supplements, to maintain optimal health.
The Complex Nature of Melanin: More Than Just a Skin Pigment: Melanin is a complex pigment produced by melanocytes in melanosomes, with different forms like eumelanin and pheomelanin, and functions including skin color, UV protection, and neuroprotection.
Melanin, the pigment responsible for skin, hair, and eye color, is not a simple substance but a complex one with various forms and functions. Melanin is produced by melanocytes in melanosomes, and the balance between eumelanin (brown or black) and pheomelanin (yellow or reddish) depends on the pH in the melanosomes. Humans have both types of melanin, and the proportion varies due to genetic factors. Some genes, like MC1R, can influence the balance, leading to red hair, freckles, or even albinism. Freckles are not caused by an increase in melanocytes but an increased production of melanosomes in response to UV radiation. UVA and UVB rays have different effects on melanin: UVA penetrates deeply and can cause aging and cancer, while UVB damages the DNA and leads to sunburns and skin cancer. Pheomelanin, the red and yellow pigment, is phototoxic and does not protect against UV radiation like eumelanin. Humans also have neuromelanin, a form of melanin found in the brain, which plays a role in various functions, including the production of dopamine and the protection of neurons. Some research suggests a link between red hair, a higher proportion of pheomelanin, and an increased risk of Parkinson's disease due to neuromelanin's role in neuroprotection. Melanin is not limited to humans; it is also found in various organisms, including fungi. The complex nature of melanin and its various roles in different organisms continue to be areas of ongoing research.
Melanin: A protective pigment in fungi, plants, and animals: Melanin, an ancient pigment, protects organisms from thermal and solar radiation, with fungi being particularly efficient producers. Darker skin may not heat up more due to radiation interaction, and melanin lies in the epidermis, with melanocytes producing and dispersing it into keratinocytes for protection.
Melanin, a pigment found in both plants, fungi, and animals, serves multiple functions, including protection from thermal and solar radiation. Fungi, in particular, are efficient producers of melanin. From an evolutionary perspective, melanin's structure is ancient, and humans and fungi share this trait. Darker skin and hair in sunny environments may not significantly heat up more than lighter skin due to the way radiation interacts with the skin. Melanin lies in the epidermis, with melanocytes, the producers of melanin, residing at the bottom of the epidermis. These cells extend dendrites that deposit melanosomes, containing melanin, into keratinocytes, which become part of the skin. The melanosomes may remain intact or disperse, providing a protective layer at the skin's surface.
The complex relationship between genetics and hair color: Hair color is influenced by melanin production and distribution in melanocytes and keratinocytes. Asian hair may contain less melanin than expected due to thicker hair shafts, and individuals with darker skin produce more melanin overall.
Melanin, the pigment responsible for skin and hair color, is produced in the melanocytes and transferred to keratinocytes in both skin and hair through a process called melanogenesis. The amount and distribution of melanin in hair shafts vary, influencing hair color. Contrary to popular belief, Asian hair often contains less melanin than expected due to the thickness of the hair shaft. Additionally, individuals with darker skin tend to produce more melanin overall. These findings demonstrate the complex interplay between genetics and physical traits. Furthermore, the study of hair samples, known as trichology, can provide valuable insights into an individual's melanin content and distribution. Overall, understanding the intricacies of melanin production and distribution offers fascinating insights into the connection between genetics and physical traits.
Undergraduate research on hair morphology and pigmentation: Determination and passion led a researcher to make discoveries about hair morphology and pigmentation using limited resources during undergrad. She wished to share individual results in future research.
Passion and determination can lead to meaningful research, even without significant resources. During her undergraduate studies, the speaker collected hair samples from various individuals, including friends and those from salons, to study hair morphology and pigmentation. She was able to make discoveries and even share results with individuals whose hair she had analyzed. However, during her PhD studies, she worked with larger samples where privacy was prioritized, and she was unable to share individual results. She expressed her desire to share such results in future research, as she believes it can be intriguing for people to learn about themselves in comparison to others. Additionally, she discussed the complexity of categorizing red hair shades and skin tones, emphasizing the diversity within these categories.
Origins of Orangutan's Orange Color and Human's Blue Eyes: Orangutans have orange hair due to pheomelanin, while blue eyes in humans result from the Tyndall effect. Cultural norms may influence personal hygiene and skin color, but scientific research on this topic is limited in anthropology.
The colors of animals and humans are determined by different pigments and structures. Orangutans have orange hair due to pheomelanin, while blue eyes in humans result from the Tyndall effect. The cultural discussion around personal hygiene and skin color on Twitter has caused heated debates, with some suggesting that lightly pigmented individuals, particularly white people, may not realize the importance of washing certain body parts due to cultural norms. However, the scientific understanding of how skin color and moisture retention are connected is not well-researched in anthropology. While there are various methods to exfoliate and cleanse the body, there is currently no extensive body of literature on this topic in the field of anthropology.
Labeling and categorizing people based on race or skin color can have significant consequences: Using race-based labels oversimplifies complex issues, leading to unequal treatment and inaccurate assumptions in medical and scientific contexts. A more nuanced and respectful approach is necessary to promote equity and fairness.
The way we label and categorize people based on their race or skin color can have significant consequences, particularly in medical and scientific contexts. As discussed, the use of labels like "African American" or "ashiness" can oversimplify complex issues and lead to misunderstandings or inaccurate assumptions. For instance, the use of race-based coefficients in medical studies can result in unequal treatment and worse health outcomes for certain groups. Moreover, the visibility of certain conditions like ashiness can be amplified on darker skin tones, leading to cultural and political implications. It's essential to be mindful of the language we use and the assumptions we make to ensure respect and accuracy in our understanding of human variation. Ultimately, a more nuanced and respectful approach to discussing and measuring human variation is necessary to promote equity and fairness.
Understanding Human Variation: Ancestry as a Continuous Spectrum: Human ancestry should be viewed as a continuous spectrum, not distinct types or subspecies. Our understanding of human diversity is constantly evolving, and it's essential to recognize the complexity of human history and interaction.
When creating datasets for AI systems, it's crucial to consider and represent the full range of human variation. Human differences, including ancestry, should not be viewed negatively or as a ranking of superiority. Ancestry can be a helpful way to understand shared genetic backgrounds, but it's essential to remember that humans are a relatively new species with a complex history of interaction and intermingling. The concept of ancestry should be thought of as continuous, not as distinct types or subspecies. Furthermore, it's important to recognize that our understanding of human diversity is constantly evolving, and there is still much to learn about the genetic and evolutionary basis of human differences. In my research, I plan to continue exploring questions related to hair morphology and the genetic basis for differences in scalp hair around the world. Ultimately, understanding human variation is a fascinating and neutral area of study that can lead to new discoveries and a deeper appreciation for the richness and complexity of our shared human history.
Inaccuracies in measuring skin color and properties with light-based technology for individuals with darker skin: Light-based technology like soap dispensers and reflectance spectrophotometers can provide inaccurate results for individuals with darker skin due to melanin's influence on light reflection and absorption. Proper calibration for human variation is essential for accurate measurements.
Measuring skin color and other properties using light-based technology, like soap dispensers and reflectance spectrophotometers, can be inaccurate for individuals with darker skin due to the influence of melanin on light reflection and absorption. This issue arises when these devices are calibrated based on assumptions that may not account for human variation. For instance, soap dispensers often use red light, which can be affected by melanin, leading to inaccurate readings. Similarly, reflectance spectrophotometers, used to measure melanin index, need to be calibrated for different skin types to provide accurate results. These issues highlight the importance of considering human variation and the need for proper calibration when using light-based technology to measure skin properties.
Discovering Natural Sun Protection: Red Ochre's Role: Red ochre, a natural sunscreen with an SPF of up to 13, was used for cosmetic purposes and sun protection for potentially hundreds of thousands of years. Everyone can benefit from reducing solar radiation exposure, regardless of skin color. Skin conditions like blotchy tans, freckles, and vitiligo impact melanin production and require various treatments.
Humans have been using natural sun protection, such as red ochre, for potentially hundreds of thousands of years. This discovery likely occurred around the same time as the first use of ochre for cosmetic purposes. Red ochre, a type of iron oxide, has a sun protection factor (SPF) of up to 13, making it an effective sunscreen. The use of natural sunscreen isn't limited to those with dark skin, as everyone can benefit from reducing their exposure to solar radiation. Blotchy tans, a common concern for some individuals, can be caused by various factors, including freckles and hormonal changes. Vitiligo, an autoimmune condition that destroys melanocytes, is another condition that affects melanin production and results in areas of skin with less pigmentation. There is currently no cure for vitiligo, but treatments such as laser therapy, corticosteroids, and phototherapy with UVB rays can help manage the condition. Overall, the discovery and use of natural sunscreen and the understanding of various skin conditions demonstrate the importance of protecting and caring for our skin throughout history.
Hormones and genetics influence our hair color: Hormonal interactions during puberty can result in differences in hair color, such as brown scalp hair and red beards. Gray hair retains some pigment, but loses color as we age. Genetics and stress may also impact when we start to go gray.
The color of our hair and other physical traits are influenced by hormones and genetics. Beth Kennedy discussed the phenomenon of people having brown scalp hair but red beards, explaining that it's likely due to hormonal interactions with melanocytes during puberty. Katie Munoz asked about the Neanderthal theory of blonde hair and blue eyes, but it was debunked as a misconception. Katie Stomps questioned why some people go gray earlier than others, and it was suggested that genetics and stress may play a role. Tim Flarr asked if gray hair can regain its original color, and it was explained that while gray hair loses pigment as we age, it still retains some eumelanin, which gives it a silvery appearance. Overall, the discussion highlighted the complex interplay of hormones, genetics, and aging in determining our physical traits.
Stress and Hair Graying: A Role for Mitochondria: Stress may contribute to hair graying, possibly through mitochondrial metabolism. Melanin, which protects against damage, is essential for aging, shielding against UV radiation, DNA, and collagen damage.
Stress may play a role in hair graying, as noted in a July 2021 cell biology paper. The paper also suggested that metabolism in mitochondria might be involved. Meanwhile, melanin, which provides protection against damage, not only shields against UV radiation and DNA damage but also collagen damage, making it an essential factor in aging. Regarding body hair distribution, it's believed to be influenced by hormones and hormone receptors. Lastly, sunscreen is crucial for protecting the skin from damage, and there are various effective options available.
Historical and cultural contexts of skin bleaching: Throughout history, beauty has been tied to what's hard to obtain or high status, leading to practices like skin bleaching, which have cultural and societal roots.
The pursuit of beauty and desirability throughout history has often been tied to what is difficult to obtain or associated with high status. From food and adipose tissue to tanning and advanced technologies like BBLs, the allure of beauty has shifted over time, often leading people to spend significant resources and even harm themselves in the process. Dr. Tina Lassi, a science communicator and soon-to-be assistant professor at the University of Michigan, discussed the historical and cultural contexts of skin bleaching and its connection to colonialism and societal pressure. She also shared her passion for studying human variations and the fun of asking "what happened?" in her discipline. Despite the challenges of focusing on one research question and the excitement of her upcoming lab, she remains committed to her unique and rewarding career in academia and science communication.
Exploring Secrets and Humanity with Ologies Now Podcast Team: Embrace humanity, cherish memories, and savor life's little pleasures like tiger nuts, as shared by the Ologies Now podcast team.
The Ologies Now podcast team includes Zeke Rodriguez Thomas, Mercedes Maitland, Kelly r Dwyer, Jared Sleeper, Mercedes Maitland of Maitland Audio, Mark David Christiansen, and Nick Thorburn. They created the podcast and its theme music, respectively. A secret shared during the episode was the discovery of tiger nuts, which are tubers that can be found at Trader Joe's and are chewy in texture. They've been said to make up 80% of our ancestors' diets. The host also shared a personal secret about her sadness on Valentine's Day and her late father's sweet gestures on that day. The team encourages everyone to embrace their humanity and enjoy the little things in life, like tiger nuts and cherished memories.
