Are you implying that non natives are inherently better than natives?
One of the hallmarks of declining empires is importing people - not to say those people are better or worse, but mixing diverse peoples together is extremely hard. It has to be done slowly and carefully.
> Changing populace doesn’t change a culture any more than time does
I don’t see how you can look at the history of anyone anywhere and believe this.
While I don’t disagree mixing of diverse people can be hard, I would simply point to American history as an example of how the empire you seem to laud was built by mixing peoples relentlessly. In fact immigrants tend to be the drivers of American growth, while the native born… not so much.
I find it fascinating you think culture doesn’t change with time, but with the mixing of different people into a culture only. What culture has been unchanged with time? Language itself mutates constantly, how can a culture be static with time? How does it stay static? The people in the culture change with every birth and every death, the memory of the culture is wiped out every 100 years. Written histories are a poor tool of continuity for something as complex as a culture. Human beings themselves change radically over the course of their lives. All things are impermanent, but human culture isn’t just impermanent, it’s an illusion.
> What makes a person better than another is how they live their life, not the circumstances of their birth.
Their genetics dictate how they live their life. Environment can have an affect, but genes dictate how you react to your environment (unless you believe in God etc).
> I would simply point to American history as an example of how the empire you seem to laud was built by mixing peoples relentlessly.
Compared to the last 50 years or so these immigrants were all very similar both in history and genetics. And even then it’s been a rough ride! I agree immigrants can be great as long as they are carefully selected for.
> I find it fascinating you think culture doesn’t change with time, but with the mixing of different people into a culture only.
Cultures absolutely change over time but the rate of change is much slower than if you introduce a new people from vastly different cultures. It’s the shearing force applied by the differences that’s the issue. If it’s too powerful something has to give.
> However the magic of the plasticity of the human brain is that it can, with effort, overcome virtually any impediment
That’s quite the claim depending on how you define impediment, but as is this statement is too vague to argue with.
> I’d also point out that the more homogeneous the genetic population the worse overall outcomes tend to be.
Again this is a very vague statement where the degree of variation matters. Hybrid vigor is poorly understood and when the differences are too great result in genetically worse offspring on some axis (mules are a perfect example of this).
> So, yes, I think science is total against the idea of racial superiority not just out of its repugnant but just false and furthermore given the homogeneity issue impossible.
I’ve made no claims of superiority and you’re taking a holier than though stance against the straw man you made up. Please leave the emotional appeals out.
> I guess it’s safe to assume you think genetics has no impact on life outcomes and/or there aren’t significant genetic differences between geographically (by ancestor) populations?
This idea that genetics impacts life out comes at a population level is racial superiority, assuming you give some outcome as being qualitatively better. I don’t know how you can cut it any differently.
I definitely don’t think that genetics has any influence though on cultural adaptation. That’s entirely environmental. See adopted children from international cultures raised in a foreign culture from birth. They culturally identical while racially different.
On plasticity, I mean even granting some genetic difference that impacts some degree of adaption to some cultural normal, the brains ability to adapt even given such major structural issues like brain damage make small things like cultural adaption simple. In fact I expect given how much migration happened throughout history it’s an evolutionary necessity to be able to adapt culturally.