A bear or lion could kill either uncle, sure, but that wasn't quite the point I was expressing, nor solitary survival (I would agree that humans are a social species). I meant to say that a bloodline pampered by technology likely wouldn't be able to endure the elements of nature quite as well as one which hasn't been pampered.
Another example is that I doubt our ancient ancestors had clean tap water (or whatever equivalent) to drink, either. Yet I think were most modern people to drink water from a nearby water source without purifying it first, we'd likely find ourselves sick shortly afterwards. But that falls in line with the weaker immune system concept.
