Why Do Humans Have Different Skin Colors?

Same beach, same sun, three different skin colors. One will burn, one will tan, one will barely change. So why do humans come in every shade, and can we really blame the sun? The answer runs through a NASA map, a test tube, a striped fish, the Arctic, and a 10,000-year-old face nobody expected. 0:00 Same beach, same sun 1:02 One pigment, every shade 1:54 A map made of sunlight 2:41 Tiny umbrellas 3:13 Too late to matter 3:40 The thief and the giver 5:06 Everyone started dark 6:18 The face in the cave 8:02 So why? Sources (every claim and hedge in the video's SOURCES file): Jablonski & Chaplin 2000 (J Hum Evol), 2010 (PNAS); Sci Am 2002 — the UV map, folate and vitamin D, the Inuit Branda & Eaton 1978 (Science) — folate and UV in a test tube; Bower & Stanley 1989; MRC Vitamin Study 1991 Holick et al. 1981; Young et al. 2020; Huldschinsky 1919; NHS vitamin D advice; Lin et al. 2021 (UK Biobank) Brenner & Hearing 2008; Kobayashi et al. 1998 — melanocytes, pigment packets, melanin caps, tanning Cancer Council Australia; Arnold et al. 2022 (GLOBOCAN) — skin cancer Rogers, Iltis & Wooding 2004; Harding et al. 2000; Kamberov et al. 2018 — hair loss, sweat and dark skin Crawford et al. 2017 (Science); Martin et al. 2017 (Cell) — skin colour in Africa Lamason et al. 2005 (Science) — the golden zebrafish and SLC24A5; Norton et al. 2007; Edwards et al. 2010 — East Asia Brace et al. 2019 (Nat Ecol Evol) — Cheddar Man; Olalde 2014; Mathieson 2015; Ju & Mathieson 2021; Irving-Pease 2024; Perretti 2025 Andersen 2013; Nielsen 2014 — vitamin D and diet in Greenland Mallick 2016; Relethford 2002; AABA Statement on Race and Racism 2019; Linnaeus 1758; Ovid, Metamorphoses II; Strabo XV Subscribe for more stories like this.