I feel like there is a flawed assumption underneath the discussion: that human traits like creativity, culture, and technology are "unnatural", and that this makes their influence therefore not a part of "natural" selection. Being successful for a million years because we developed very complex brains is interesting, but trilobites accomplished a longer run and a wider geographical distribution just by developing a really good carapace. How is a brain any less a natural organ than an exoskeleton? They are both interesting combinations of carbon with survival consequences for their hosts. If our influence is still expanding, nature is still "selecting" that trait. If we end up blowing ourselves up or exhausting our food sources, nature will "select" against it.
A nest is a natural occurring object.
All members of a species of bird can build one.
Is the discovery of insulin something all humans can do?
Or is it something only a rare person could do?
Innovating a new object or strategy to deal with a novel situation is an inherently human thing to do, and our brains prime us to both experiment individually and collectively process the knowledge gained. The discovery of insulin is a demonstration of both qualities, as it was the work of a great many people over the course of several generations; several centuries of study, encoded in culture and language and passed along between interested persons in similar environments. Langerhans may get credit (fairly) for launching the modern inquiry into the hormone, but it is not as though he was sitting naked on the savannah and suddenly invented the microscope, centuries of anatomical study, existing theories about the functioning of cells, etcetera. Nor was he the one to apply an expanding knowledge of bodily sugars to the question of his "funny little cells", nor the first to turn the knowledge into a practical means of medicine. How can you portray as a rare flash of individual brilliance something that took thousands of people to accomplish? And that any human, given the apparatus, circumstances, and motivation, is equally
capable of observing? I do think that having all three of those circumstances met is a rare occurrence, but not because those it happens to are somehow outside the normal range of potential for our species. If Langerhans had been the only person
able to see and speculate about the role of insulin, no one would have believed him or cared about his claims; singular, indemonstrable observations are not the way of science. Scientific observations are elevated from other claims by the very fact that any human, should they correctly reproduce the conditions of the original observation, will be able to observe the same thing.