Under ideal circumstances, the likelihood of humans producing babies after one incidence of sex is roughly 30%, based on the genetic evidence, the odds of a human and Neanderthal mating producing offspring would have been dramatically lower, like in the single digits or even fractions of a percent. Assuming (as I think is likely) that such societies figured out that babies = sex, its not going to take Thag too long to figure out that his Neanderthal wife ain't making very many babies, and when she does make babies, they tend to die at an early age. So, Thag's not going to want to keep his Neanderthal wife, and nobody else in the village is going to want to have a Neanderthal wife, which means that the chances for a human/Neanderthal offspring are going to be already lower than what they would be if they were routinely bumping uglies. Add to that, when the offspring are born, their going to be at a genetic disadvantage so the number of them who could reach breeding age and be fertile, are going to be even smaller. Statistically speaking the odds favor none of Neanderthal genes surviving into humans, but they did. And the only way they could have, is if humans and Neanderthals were boinking a lot up until the time Neanderthals went extinct. Why would they continue to do so, if it was unlikely to produce offspring, and the offspring it did produce were unhealthy?
Kind of like some tribes of Plains Indians "counting coup". If you carried a "coup stick" which was just basically a harmless long stick into battle and could get close enough to touch an armed enemy with your stick but not get hurt, you are a better warrior and have heaped shame upon that enemy.
Okay, but then there's this: Neanderthals "Not Fully Extinct" and this: Neanderthal Genes for Red Hair and More...
They certainly couldn't get pregnant since being castrated means no erections - always a "mood killer" in romantic situations. That's one reason eunuchs were often used to guard harems - you wouldn't have to worry about them messing with the ladies.
It depends upon when they were snipped. https://closetprofessor.com/2010/07/15/the-sex-lives-of-eunuchs/
Holy shit..... way, way more about eunuchs than I ever thought I would need. Could have done without those pics though - they didn't add anything necessary to the story. Regardless, interesting bit of trivia!
I don't ever get this. If our species had truly been around for the past 100,000 years, why does anybody think they were primitive? We aren't. Neither were the Romans or Pershians or Anunaki they all built great societies. If "Life after People" is to be believed all remnants of our society would be gone within 100 years, unless it was made of stone. Its why I believe the theory of a meteorite hitting the NW 12,900 years ago and causing the extinction of those living in NA and set back those in Europe and China. That would also heolp explain why the Sphinx has evidence of water erosion, why Goblei Teppi was buried, and the new site in SE Asia that are all dated to more than 12,000 years ago. If there was a catastrophic meteorite impact their civilization, with the exception of stone buildings and even then many would fall in, would be gone shortly.