system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How/why do we develop freckles on parts of our body that aren’t exposed to sunlight?
gpt
Why do black and brown people have brown skin in regions not exposed to sunlight? 

Same thing. Freckling is just a particular skin types ‘strategy’ for distributing melanin. Freckling is more prominent in areas exposed to sun because exposure to UVB stimulates melanin production, but everyone has some baseline level of melanin production.


Alternatively, what *you* may be seeing and calling freckles are in fact nevi or moles. Some families carry a trait that causes the expression of dozens of moles all over the skin with such a broad distribution they can look a bit like freckles, but upon closer inspection you’ll see that they’re raised instead of flat like freckles. Moles are melanocyte dysplasia or irregular growth. Melanocytes make melanin and dysplasia is called dysplasia because it happens whether exposed to stimulus (sunlight) or not. The melanin makes them dark, but they show up with or without sun because that’s just how those cells are programmed. They are not all cancerous or even mostly but people with this condition need to be screened yearly by a dermatologist because any of these moles can transform .