Early Human Adaptation and Migration
📌 Early humans in Africa, roughly 250,000 years ago, almost certainly had dark skin as a biological adaptation for protection against damaging UV radiation in the sunny Savannah.
🗺️ Significant human migrations began around 60,000 to 70,000 years ago, spreading from Africa across the Eurasian landmass in multiple events.
🌍 By around 10,000 years ago, human expansion covered nearly the entire globe, resulting in a linear pattern between skin color and latitude.

Genetic Basis for Skin Color Variation
🧬 A key mutation occurred in the KITLG gene in ancient human populations expanding into the Northwest Arabian Peninsula around 70,000 years ago, leading to lighter skin compared to groups migrating south into the Indian subcontinent and Australia, who retained dark skin.
❄️ Further genetic mutations in Europeans expanding into Northern latitudes affected the transporter proteins SLC24A5 and SLC45A2, compromising melanin production and leading to lighter skin due to low sun exposure.
💡 A mutation in the MFSD12 gene in populations migrating northeast in Asia shifted pigment production from dark melanin toward the lighter pigment pheomelanin.

Key Points & Insights
➡️ Human skin color is a fairly basic biological trait that has been in constant flux throughout human history, driven by natural selection and migration patterns.
➡️ Ancestral populations originating near the equator (low latitudes) generally have darker skin, while those from higher latitudes tend to have lighter skin.
➡️ Mutations in genes like OCA2 and MC1R also independently contributed to lighter skin in Northern latitudes by affecting melanin production pathways.

📸 Video summarized with SummaryTube.com on Jan 12, 2026, 18:59 UTC