There was another species of human on Earth besides Homo sapiens. Until something intervened.
The most shocking result of Ancient Alien visitors may be us.
Strange to consider, but our species - homo sapien - was not the only species of human on Earth for a while. Quite a long while, actually. For over 5,000 years, you could have lived in a world where your neighbor was a Homo neanderthalensis. They looked a bit different - they were short and stocky, with large brow ridges. But they were otherwise familiar. They had human bodies, made tools, hunted, buried their dead, and likely developed language. You might have been friends with a Neanderthal, or even something more -- around 2% of the global population has neanderthal DNA in them right now.
But 40,000 years ago, something happened we haven't been able to explain: Homo neanderthalensis ceased to exist.
Their extinction is one of the most intriguing mysteries in paleoanthropology. Why did an entire species of humans died out? Was there a climate disaster? War with Homo sapiens? But a new study points to something much stranger. Their genetic structure was changed. And not gradually over time. There was a single event that disrupted their biology and ended their time on the planet.
The study of neanderthal genetics was published in January, 2025 by researchers from eight different Universities around the world, including the University of Madrid and Binghamton University in New York. Scientists focused on a very specific part of the Neanderthal fossil record: the inner ear. Turns out, the DNA of this semi circular maze of canals isn't much affected by natural selection or survival pressures. What you get is a better generational representation of the Neanderthal's genetic make up. Put simply, researchers could compare how their DNA profile varied across generations.
They found that early Neanderthals had a "high phenotypic diversity", meaning they had many variations in hair colors, facial features, and behaviors. Sounds familiar - Homo sapiens enjoy the same diversity. Then something happened. In the late Neanderthals - the generation that became extinct - this genetic variation disappears. Suddenly they're all the same.
When a species is too similar genetically, it can no longer adapt. It becomes vulnerable to extinction. Imagine a deadly disease hits. In normal cases, a healthy species has members with the genes to fight it, even as others die off. But if a deadly disease hits a species with low diversity, it hits them all equally - there's suddenly a chance it can wipe out a whole population. Biologists call it a bottleneck problem. It's why inbreeding is a bad thing. Well, it's one reason.
Now we know, it's exactly what happened to Neanderthals between the Middle and Late Pleistocene epochs. Researchers call the change "especially striking and clear". With DNA diversity reduced, Homo neanderthalnesis had no chance to survive the world.
What - or who - intervened to alter the genetics of these fellow humans?
Ancient Astronaut theorists believe Neanderthals were a genetic experiment by advanced aliens, a crazy thought. Except, given these new findings, it doesn't seem so crazy. It explains the sudden shift in ancient DNA. Something happened that gave rise to modern humans.
Are traits in us like high intelligence, or unusual artistic abilities, remnants of these alien genetic experiments? Is the rapid leap from Neanderthals to Homo sapiens explained by alien intervention?
Makes you think twice about the Neanderthal DNA still found hanging around in us.
