Exactly, I'd like to know his reasoning. Why wouldn't there continue to be a continuum between the two groups, eg? We don't get 'purer' now, why would they, relying on technology, ie presumably with no selection pressure except mating preference, do otherwise?
edit: He explains it as, the 'upper' castes take off from the rest of us; we already mate assortatively, this would just be an extreme. But, why wouldn't we put good genes into our children, a la 'Gattica'? Well, if we have economic /laissez faire/, maybe the poorer ones won't be able to afford it, and increasingly so.
i think he's missing an even bigger thing: there's a very high probability that unless we humans transcend our humanity somehow, we'll probably just make ourselves extinct before we evolve further...
Then again like Asimov said, saying something isn't possible typically turns out wrong in the long run...
Why do you think we will "probably" go extinct? That depends on creating risky knowledge faster than we create knowledge of how to mitigate those risks. Which in general seems unlikely, given that we are aware of the issue and can aim our progress in the right direction as necessary.
Well, 'risky' knowledge seems generally easier to research than the knowledge to contain it. See the atomic bomb vs. the missile shield, over 60 years later. It's easier to destroy than to create.
Also, humanity isn't exactly united in aiming our progress in the right direction. However, I don't think we'll go extinct any time soon (that would take nothing less than a very big asteroid).
but we didn't and still don't necessarily need a missile shield to prevent the atomic bomb from destroying us. we had, and used, diplomacy, locked weapons silos, etc
edit: He explains it as, the 'upper' castes take off from the rest of us; we already mate assortatively, this would just be an extreme. But, why wouldn't we put good genes into our children, a la 'Gattica'? Well, if we have economic /laissez faire/, maybe the poorer ones won't be able to afford it, and increasingly so.