The Tibetans and Han Chinese share several genetic traits and DNA. However, the EPAS1 gene, which increases the ability of red blood cells to carry oxygen even in low oxygen environments, is only commonly found in the Tibetan population that live in higher elevations. Explain why this gene is only common in Tibetan populations from the perspective of competitive advantage and natural selection. Write your answer in three to five sentences.
The presence of the EPAS1 gene allows Tibetans to better adapt to living in high altitude environments where there is lower oxygen availability. This provides a competitive advantage for survival and reproduction over individuals who lack the gene. As a result, over time, the gene became more prevalent in Tibetan populations due to natural selection. In contrast, Han Chinese populations living at lower elevations did not face the same selective pressures, so the gene did not become as prevalent.
