Harvard University Study of 22,000 Ancient Genomes Reveals 500 New Genetic Shifts in Human Evolution

Scientists analyze 22,000 ancient genomes to find 500 genetic shifts. New data reveals how natural selection shaped risks for celiac and MS.

By: AXL Media

Published: Apr 24, 2026, 6:04 AM EDT

Source: Information for this report was sourced from The Times of Israel

Industrializing the Extraction of Ancient Genetic Codes

The study, led by Harvard geneticist David Reich, marks a milestone in paleogenomics by "industrializing" the process of DNA sequencing. By employing robotic systems to extract and clean DNA from remains found in archaeological sites across Iceland, Russia, Iran, and Israel, the team was able to process a staggering 22,000 genomes. This dataset includes 10,000 individuals whose DNA had never been analyzed before, allowing scientists to move beyond studying the "scars" of evolution on modern populations and instead observe genetic shifts as they happened. The researchers collaborated with 270 archaeologists to ensure precise dating through radiocarbon methods and soil layer chronology.

Identifying Natural Selection Amidst Human Migration

A primary challenge in tracing evolution is distinguishing between changes caused by natural selection and those resulting from simple human migration. Senior staff scientist Ali Akbari developed a statistical model that compared 10 million distinct letters across the 22,000 genomes to filter out the noise of population movements. Prior to this research, only 21 genetic shifts due to natural selection were confirmed by the scientific community. This study has increased that number to nearly 500 positions, with thousands more potential candidates identified, revealing how the human body actively adapted to changing environments and diets.

The Paradoxical Rise of Celiac Disease Variants

One of the most striking findings involves the rapid increase of DNA variants associated with celiac disease risk roughly 4,000 years ago. Logic would suggest that as ancient civilizations like the Minoans increased wheat consumption, natural selection would favor those less susceptible to gluten-related issues. However, the study found the opposite: susceptibility increased. Researchers speculate that these specific variants may have provided a hidden evolutionary advantage, such as protecting the body against a different, more lethal infectious disease that has yet to be fully identified in the ancient record.