Final answer:
Tibetans acquired genetic adaptations approximately 8000 years ago that enable them to survive in high altitudes. These adaptations include mutations in genes such as EPAS1 and PPARA, which are associated with increased lactic acid concentrations in the blood and fatty acid production, respectively.
Step-by-step explanation:
Tibetans acquired the ability to survive in high altitudes through genetic adaptations that occurred approximately 8000 years ago. One of the key genetic changes observed in the Tibetan population is a mutation in the EPAS1 gene, which is associated with increased lactic acid concentrations in the blood. Another mutation, PPARA, is correlated with fatty acid production, similar to what is seen during hibernation. These genetic adaptations allow Tibetans to cope with low oxygen levels at high altitudes.