Friday , November 27 2020

Altitude May Help Andes People Survive with Europeans

<img data-attachment-id = "446100" data-permalink = "" data-orig -file = "" data-orig-size = "1000 , 661 "data-comment-opened =" 0 "data-image-meta =" {"openings": "0", "credit": "", "camera": "", "description": "", " created_timestamp ":" 0 "," copyright ":" "," focal_length ":" 0 "," iso ":" 0 "," shutter_speed ":" 0 "," title ":" "," orientation ":" 0 "}" data-image-title = "Andes" data-image-description = "

Andes Macchu Picchu

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Andes Macchu Picchu

"data-medium-file =" "big data- file = "" class = "aligncenter wp-image-446100 full size "src =" "alt =" "width =" 1000 "height =" 661 "srcset =" 1000w, https: // 300w, com / wp-content / uploads / 2018/11 / Andes.jpg? resize = 768% 2C508 & ssl = 1 768w, /Andes.jpg?resize=24%2C16&ssl=1 24w, 1 36w, / upl oads / 2018/11 / Andes.jpg? resize = 48% 2C32 & ssl = 1 48w "sizes =" (maximum width: 1000px) 100vw, 1000px "data-recalc-dims =" 1 "/>(CN) – Adapting to higher altitudes gives people in the Andes Mountains the advantage of most residents of the "New World" unfortunately do not have: They were able to avoid being completely erased by the disease of European colonists, according to new genetic studies of people in the region.

On a continent full of hard climates, the Andes are the most intense with freezing temperatures, ultraviolet radiation and low oxygen levels. But humans adapted to the area thousands of years ago.

By studying the complete genome of ancient people in the Andes and comparing it with modern South American genetics, the research team looked at how the digestive and cardiovascular systems of people might have adapted.

The cardiovascular system of people in the highlands may have adapted in a way that allows more blood to flow to their lungs, the team concluded in a study published in the journal Science Advances.

"This is a hard, cold, resource-poor environment with low oxygen levels," said Anna Di Rienzo from the University of Chicago, who led the study. "But people there adapt to that habitat and the agrarian lifestyle."

The team compared seven genomes of ancient Andean people and compared them with 64 genomes from the current population in the highlands, as well as indigenous people from Bolivia and the coast of Chile.

They hoped to analyze what the impact of European colonizers on the indigenous population, many of which were almost destroyed by contact with outsiders in the 1500s.

The team concluded that people living in higher altitude areas had a much smaller population decline than those at lower altitudes, and they had several possible explanations.

While demographic models and records show that up to 90 percent of lowland residents were destroyed after European contacts, those living in higher areas experienced a population decline of only 27 percent.

One explanation might be genetic modification that increases their ability to breathe oxygen-deficient air at high altitudes.

The team found evidence that a gene called DST, related to the formation of the heart muscle, had been changed. This may have allowed people to take oxygen more effectively.

The shift to a plant-based diet based on potatoes, originating from the area, might also play a role in the survival of the Andeans.

The presence of a gene called MGAM, which helps people digest starchy foods, convinced the team that "significant dietary changes from one that is likely to be more meat based on one plant based again."

"The timing of the emergence of variants is quite consistent with what we know about paleo-ethno-botany records on the plateau," said anthropologist Mark Aldenderfer.

Potatoes, native to the region, may have been domesticated 5,000 years ago, according to the latest research.

The team also found that modern people living in the mountains had high genetic closeness with ancient Andeans who lived in the region before European contacts.

Very likely, they concluded, that modern people are descended from people who survived the epidemic of smallpox and others.

"Contact with Europeans has a devastating impact on the population of South America, such as the introduction of disease, war and social disorders," said John Lindo of the University of Chicago.

"By focusing on the period before that, we were able to distinguish environmental adaptations from adaptations originating from historical events."

This research was also conducted by Ricardo Verdugo from the University of Chile.

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