00:00How Horse DNA Transformed Human History
00:03Have you ever wondered what it actually took for humans to ride a horse for the first time?
00:08It turns out it wasn't just a story of courage and training, but a story written in the horse's DNA.
00:15Recent research reveals that our Bronze Age ancestors were, in essence, early biotechnologists.
00:21They intentionally selected for specific genetic traits that transformed wild animals into willing partners.
00:28This process seems to have happened in two crucial steps, focusing first on the mind and then on the body.
00:36The first major hurdle in domesticating horses was their behavior.
00:40Once horses were docile enough to handle, the focus shifted to their physical build.
00:46A bit later, between 4,700 and 4,200 years ago, a second gene came into play.
00:53Breeders began intensely selecting for a genetic variant located near a gene called GSDMC.
01:00This genetic location is fascinating because in humans, it's associated with chronic back conditions.
01:06While in horses, it's linked to their body proportions.
01:10To understand its effect, scientists ran experiments on mice and found that when the GSDMC gene was inactivated,
01:17the mice developed straighter spines and stronger forelimbs.
01:21Researchers believe a similar change in horses would have made them
01:25physically more capable of bearing the weight of a rider and moving effectively while being ridden.
01:31The impact of this second mutation was revolutionary.
01:36The variant near the GSDMC spread through the horse population at an incredible speed.
01:41In just a few hundred years, it went from being almost non-existent to present in nearly every horse.
01:48The advantage it conferred was so significant that,
01:51horses with this mutation produced an estimated 20% more offspring than those without it.
01:57As lead researcher Ludovic Orlando puts it,
02:00when you see something like that, you know you're onto something that was really a game-changer for horse biology.
02:07But this wasn't just a game-changer for horses.
02:09It was a pivotal moment for humanity.
02:13The creation of a rideable horse was one of the most significant technological advances of the Bronze Age.
02:19It completely transformed human societies by unlocking new levels of mobility,
02:24which in turn changed the face of transportation, trade, and even warfare.
02:29Although these two genes appear to be the main players,
02:33researchers acknowledge that other genes and crucial cultural innovations,
02:36like new ways of interacting with horses,
02:39also played a role that can't be seen in the genome.
02:43The next step for scientists is to analyze the DNA of horses from later steppe empires
02:48to understand how these societies continue to
02:51develop this incredible living technology.
02:54scientific means quantific
03:10and how they come from.
03:10The next step for scientists is to educate the technology to learn their powers.
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