That depends which humans. We are not one monolithic gene pool. Human diversity means that more recent migrations of humans had less time to adjust to their n

That depends which humans. We are not one monolithic gene pool. Human diversity means that more recent migrations of humans had less time to adjust to their new climates. If you compare, say Inuit, Nordic, and native Siberian populations, to subsequent equatorial populations to higher latitudes, if you could find instances of low interbreeding, I wonder if we'd see certain genetic adaptations missing.