THE AUTHOR DOESN'T MENTION WHAT SPECIES HE THINKS THEY'VE BECOME:

Tibetans fastest case of evolution? (Nicholas Wade, 7/04/10, NYT News Service)

Tibetans live at altitudes of 13,000 feet, breathing air that has 40% less oxygen than is available at sea level, yet suffer very little mountain sickness. The reason, according to a team of biologists in China, is human evolution, in what may be the most recent and fastest instance detected so far.