HMM: Human Skin Didn’t Always Fear The Sun, Not Until A Huge Change 10,000 Years Ago. “Human beings evolved under the Sun. Sunlight was a constant in people’s lives, warming and guiding them through the days and seasons. Homo sapiens spent the bulk of our prehistory and history outside, mostly naked. Skin was the primary interface between our ancestors’ bodies and the world. Human skin was adapted to whatever conditions it found itself in.”