Campbell, Heinlein, Piper...

      The "General Specialist."  Anyone who grew up reading the kind of Science Fiction John W. Campbell sought out and encouraged during his time as editor of Astounding, later Analog magazine will recognize the term and the idea behind it: that humans are adaptable and the best of us adapt readily and well as conditions change.

     I think Robert A. Heinlein and H. Beam Piper provided some of the best examples, though there were plenty of others -- certainly Eric Frank Russel's slightly more cynical heroes fit, and his most aspirational works suggested that intelligence and adaptability were going to be found in any dominant intelligent species.  At its worst, it could become a kind of tiresome "humanity über alles" trope, but at its best, the idea inspired readers to learn and grow, to understand that figuring out what you needed to do to survive and then doing so was well within the grasp of anyone.

     The insight became so prevalent in SF that it was almost invisible unless it was being mocked (something the New Wave occasionally delighted in -- and there's no idea so wondrous that it is above question, after all).  Outside SF, it wasn't so obvious.

     What was obvious, at least to the scientists who study early man and emergence of clever hominids, was that there used to be a lot of upwardly-mobile primates with decent thumbs and big brains on our planet, and now there's just us.  So what happened?

     The archeological record suggests we ate some of 'em; the genetic record suggests we married some of 'em.  But that doesn't account for it, not even close -- and, really, while we have given up eating strangers (and friends), we're still marrying them and yet plenty of our much smaller differences to one another persist.  So we're still here, in all our different hues of eyes, hair and skin and what we'd like for dinner,* but the early cousins of our species are all gone.  What happened?

     We may have pushed them out by being more adaptable: homo sap. fills niches, from freezing cold to blistering hot, from humid climates to dry ones, from coastal plains to the highest valleys, our ancestors showed up, figured out where to find water, what plants grew there, what animals lived there, and which of them were good for dinner (not to mention which ones to look out for!).  And our cousins weren't as good at that.  If their climate changed too much, they were in trouble, while our ancestors were busy making new menus.

     Maybe we're just that adaptable.  And perhaps they weren't.
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* I'm thinking pizza and an early dinner.