Science & Tech · Science & Environment · 18 hrs ago
Evidence Shows Humans Are Still Evolving
Human evolution is still happening, and some changes can be seen in the body.
Natural selection can make inherited traits more common when they help people survive or have children.
After people began keeping cattle and drinking milk around 10,000 years ago, genes for lactose tolerance spread in parts of Europe, East Africa and the Middle East.
Among Quechua people of Indigenous Andean ancestry, researchers found evidence of genetic adaptation to a potato-rich diet.
On the Tibetan plateau, long-term high-altitude living has been linked to blood traits that help deliver oxygen.
These examples show how different diets and environments can shape human biology over many generations.
Evidence from studies of diet and high-altitude living suggests that humans are still evolving.
Lactose-tolerance variants spread in parts of Europe, East Africa and the Middle East after people began keeping animals for milk.
Research suggests that Indigenous Andean people have genetic traits associated with digesting starch from potatoes.
Tibetan communities have adaptive traits that improve the blood’s ability to deliver oxygen at high altitude.
A study of 417 Nepalese women found that higher oxygen saturation in red blood cells was associated with more live births.
- Who
- Humans, including Indigenous Andean and Tibetan communities, are the focus of the reported evidence.
- What
- Studies describe genetic and physiological adaptations linked to diet and high-altitude living.
- When
- Some changes are traced to around 10,000 years ago; a Tibetan high-altitude study was reported in 2024.
- Where
- The examples include Europe, East Africa, the Middle East, the Andes, and the Tibetan plateau.
- Why
- The reported adaptations are linked to natural selection in response to diet and environmental conditions.
This story does not have two clearly opposing sides.
People in some regions began domesticating cattle and other grazing animals and later learned to milk them.
Indigenous Andean ancestors began growing potatoes, with higher copy numbers of a gene variant associated with a reproductive or survival advantage.
Cynthia Beall and her team reported evidence of adaptive traits in Tibetan communities that improve blood oxygen delivery.
Researchers reported that Quechua people of highland Indigenous Andean ancestry appear particularly equipped to digest starch.
- Lactose tolerance
- About 30 to 35 percent of adults worldwide can tolerate lactose.
- Andean gene variant
- People with roughly 10 or more copies had a 1.24 percent survival or reproductive advantage per generation.
- Tibetan high-altitude study
- The reported adaptive traits improve blood’s ability to deliver oxygen.
- Nepalese participants
- 417 women who had lived above 3,500 meters were studied.
- Live births
- Women with the highest rate of live births showed unusually high red blood cell oxygen saturation.
What people are saying
Biologists have long suspected that different groups of humans have evolved genetic adaptations in response to their diets
But there are very few cases where the evidence is this strong.
This is a case of ongoing natural selection
We knew that higher oxygen saturation of hemoglobin was beneficial; now we understand that the higher the saturation, the more beneficial