About 7,000 years ago the people in the Andes developed bigger hearts and a slightly higher blood pressure to adapt to the conditions of living in such a high place.
According to Live Science, all of this appeared in a new genetic analysis, and the changes may have occurred soon after people began to settle permanently in the highlands.
"Despite harsh environmental factors, the Andes were populated relatively early after entry into the [South American] continent," the researchers wrote in a study published in the journal Science Advances, said Live Science.
They also mention that archaeological findings indicate that the people who hunted and gathered food began living in the Andes 12,000 years ago, and its permanent occupation about 9,000 years ago.“The scientific team collected DNA from the remains of seven ancient people found at sites from one of three different cultural periods: The Soro Mik'aya Patjxa, an 8,000- to 6,500-year-old site where hunters and gatherers lived; the Kaillachuro, an approximately 3,800-year-old site whose people transitioned from foraging to farming; and the Rio Uncallane, a series of cave-crevice tombs dating to about 1,800 years ago”, said Live Science.
The findings show that in addition to the adaptations to the heart and blood found in highlanders, “the analysis revealed that low- and high-elevation populations split about 8,750 years ago, when people began living permanently in the Andes Mountains”, you can read in the aforementioned media.