Lecture 8 - Skin Pigmentation Flashcards
What are the main functions of the skin?
- Protection
- Thermal regulation
- Sensation
- Hydration
- Vitamin D synthesis
- Protection from UV
What does the evolution of human skin tone suggest about our last common ancestor?
Lighter skin tone and pelts.
What produces melanin in the skin?
Melanocytes.
What does Gloger’s Rule state regarding pigmentation?
Greater pigmentation in populations that are lower latitudes. The further you are from the equator, the lighter your skin is. CLINAL.
Where did Homo sapiens evolve, and what was the initial skin tone? What changed?
Our Homo sapiens ancestors in Africa had much darker skin. The change in skin pigmentation 50k BP indicates a severe environmental impact.
What is folate, and how does it relate to UV exposure?
- a vitamin that is acquired from your diet
- degrades with UV exposure
- if not enough folate in utero, can cause spina bifida
What is vitamin D, and how does UV radiation affect it?
- vitamin that helps with skeletal growth and calcium transportation
- we need UV rays to produce it
- causes health issues if insufficient
How many genes control skin tone?
About 60.
What was significant about ‘Cheddar Man’?
Prehistoric remains in UK, oldest human remains found in the UK, had dark hair, dark skin, and bright blue eyes.
