Evolution, Evolution, Evolution
...At least everything human. And I actually think pretty much everything that's alive, including plants, "germs," bugs and irresistible puppies are all fully explainable by evolution.
I've bought into the idea that if a human trait - even a weird one - is around today, it was survival-positive at some point in our evolution, thus became part of what the human race is. For instance schizophrenia, not a trait you might consider all that valuable these days. But back there in deep pre-history, the schizos probably were very effective shamans, and a tribe with a really wild shaman had survival advantages. You can write the scenario as well as I can.
In one of my fav magazines NewScientist writer Kate Ravilious 07 November 2011)EVERYTHING Is Explained by Evolution" bit. She summarizes (and adds to) the work of archaeologist Penny Spikins at the University of York, UK. Part of her theme is that our tendency to embrace people with various mental ailments is exactly what let us outcompete the Neanderthals, the Denisovans, the Hobbits and all the other human wannabes.
Unless you subscribe to NewScientist, you probably can't get this article, but here's a telling excerpt:
Evidence of religion and spirituality also appear during this period. It has been argued that shamans were responsible for painting the more metaphorical and dream-like cave art, and Spikins believes they would have had a big impact on society. "I think that they helped to bind people together, by helping them to make sense of their world, through myths, ritual and a belief in a spirit world," she says. In modern hunter-gatherer societies shamans tend to be unusual and creative people, who sometimes go into trances. Some also express traits associated with schizophrenia, such as hearing voices, and other mental disorders. "Using modern criteria to diagnose mental illness, I think we would say that most shamans appear to have had mood disorders - most probably bipolar disorder," says David Whitley, author of Cave Paintings and the Human Spirit (Prometheus, 2009).
Just imagine the various advantages if your tribe had an obsessive-compulsive (the fire never goes out), or a manic (always watching the cave door for intruders), or a depressive (pointing out possible dangers), etc. If the tribe down the creek didn't have some resident loonies, you out-survive them!
Try to explain that with Creationism.
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