Ninety percent of Tibetans share a genetic mutation that prevents their blood from becoming dangerously clogged with red blood cells at high altitudes—a response that can be deadly for non-native mountaineers. Karen Hopkin reports.

Source: www.scientificamerican.com

Genetic adaptations to a specific environment show how people are can be culturally and environmentally tied to a given land.  While most geographers are nervous to mention examples such as these for fear of being labeled too ‘environmentally deterministic,’ it does not hurt to show how that it is possible.