This is a riff on an Interesting Engineering article by Rupendra Brahambhatt
For much of human history, survival and progress depended on how far and how fast people could move. Before cars took over in the 20th century, it was horses that carried humanity forward. Until recently, nobody exactly knew what made wild horses rideable. Scientists suggest the answer may be in their DNA.
Our equine allies have pulled carts, plowed fields, and fought battles for thousands of years. The domestication of the horse was one of humanity’s significant turning points, powering agriculture, trade, migration, and conquest. Yet, despite their enormous impact, humans domesticated horses long after they had tamed sheep, goats, pigs, and cattle. It has always been a mystery what exactly transformed untamed, wild horses into rideable, strong, and relatively gentle companions. An article in the August 2025 issue of the journal Science discusses the biological changes that made equine domestication both practical and possible.
It may be in their DNA
Earlier studies could tell that domesticated horses came from the Don-Volga steppes of eastern Europe, about 4,200 years ago, but they failed to answer how wild animals became tame enough to ride. The missing link was in the biology of behavior and body build. This study’s authors analyzed DNA from thousands of ancient horse remains, some dating back 5,000 years, focusing on specific genetic markers instead of the entire genome all at once. Scientists already know that these small, identifiable pieces of DNA influence key traits such as coat color, body structure, locomotion, and behavior.
By comparing DNA across centuries, the researchers spotted two crucial shifts. The first appeared around 5,000 years ago in a DNA region tied to a gene linked to tameness. In mice, this gene modulates behavior, and in horses, it seems to have played a similar role. According to the study authors, horse keepers about five millennia ago promoted the rise of this gene by selecting less aggressive, more manageable animals to train, laying the foundation for full domestication, which suggests that early horse trainers themselves took the earliest selective breeding steps towards full domestication. Their experience with other domestic animals may have had an influence.
Another major shift happened a few centuries later in a gene that influences the physical build of a horse. Experiments with mice show that changes to this gene affected the spine, motor coordination, and muscular strength. In horses, this meant stronger bodies, better coordination, and a physique better suited for riding. Within a few hundred years, these genetic variants swept through horse populations, giving rise to the modern bloodline of domestic horses that enabled humans to harness horsepower.
Why does this matter?
By pinpointing the genes that drove this transformation, scientists now understand the process in much greater detail. First came tameness, then came strength and speed. The tameness gene may have influenced more than just behavior, and domestication likely involved multiple genes working together. The findings also show how quickly selective breeding can shape an entire species. Scientists have not yet fully understood traits influenced by multiple genes in horses. Hopefully, further research will also shed light on how domesticated horses adapted to different environments around the world.
The Devil’s Own Day: Shiloh and the American Civil War
Shiloh was one of the few Civil War battles where cavalry played no significant role, but where horse casualties had a significant impact, especially on the second day.
And Finally...
On 3 October:
2333 BC: According to legend, the mythological figure Dangun Wanggeom founded the State of Gojoseon on the Korean peninsula. Gojoseon (“old Joseon”) laid the cultural and political foundations for Korea, spanning their Bronze and Iron ages.
1942: Germany conducted the first successful A-4/V-2 rocket launch from Peenemünde island in the Baltic Sea. Reaching a height of 53 miles and traveling 118 miles downrange, it became the first human-made object to reach the edge of space.
And today is UNITY DAY in Germany, commemorating the day in 1990 when East and West Germany reunited for the first time since 1945…or 1948, depending on your point of view. The Soviet Union had withdrawn its troops from the former East Germany months before, leaving the East German Army with their Soviet Bloc equipment and their maintenance headaches.
There seems to be a strong tameness gene in some humans.