What Ancient DNA Is Teaching Us About Human Evolution. |
Five landmark studies are rewriting what scientists thought they knew about our species.
People have never been the same. But recent studies indicate that the pace of change increased exponentially with the adoption of the plow by our forefathers. A flood of genetic research published over the past few months, which relies on the thousands of ancient DNA samples from burial sites throughout Europe and Asia, is redefining the way scientists think of the processes that made us what we are today.
Farming and the Acceleration of Evolution
On 15 April 2026, from 15,836 ancient genomes of West Eurasia, covering an 18,000-year range, the largest ancient DNA study ever published in Nature was conducted. The research team, headed by Ali Akbari and David Reich of Harvard University, discovered 479 genetic variants with significant evidence of natural selection. The number is an order of magnitude greater than anything that had been previously recorded by studies.
The trends that are processed are an unexpectedly descriptive tale. Genes associated with an increased body fat became uncommon after the advent of farming some 10,000 years ago. With the increased stability and predictability of food supplies, the body was no longer required to store energy in such an aggressive manner. Tuberculosis resistance variants began to increase in prevalence about 6,000 years ago. The red hair genes started to become widespread approximately 4,000 years ago. Characteristics related to male pattern baldness have been on the decline in the last 7,000 years.
The Genomic Shift: This chronology shows how the advent of farming and more established ways of life led to a sudden evolution of natural selection in such aspects as storing of fat in the body, resistance to diseases, and physical attractiveness.
There has been a huge selection pressure on the genome over the past 10,000 years, Akbari explained to Science. All this has shifted the manner in which we live, and that is being replicated in our genome, and in which it is attempting to keep pace.
Disease, Immunity, and the Bronze Age Shift
The 5,000-year-old Bronze Age was a rush of its own. With the increased population and people living in more densely populated settlements and in contact with domesticated animals, a set of mutations related to immunity and autoimmune diseases became widespread. Population geneticist Lluis Quintana-Murci of the Pasteur Institute referred to this as a phase of enormous change in disease exposure, necessitating a rapid change in the immune genes. Not all discoveries are simple to answer. Groups of characteristics associated with the pace of walking, income, and years of education also changed over the same time. According to Harvard co-author Annabel Perry, there was no college during the Neolithic; there must have been something other than that that was causing those changes. That riddle is left open.
When the Immune System Turns on Itself
The second article, in Nature, by scientists at the Wellcome Sanger Institute, Cambridge University Hospitals, and the University of Cambridge, links the evolutionary narrative with a very contemporary issue. The range of autoimmune........