I like how evolution almost seems prepared to dispense with an organ if it demands too much energy. We don't need to be technologically advanced and emotionally developed creatures in order to propagate our genes. We just need to be able to live and spread our seed. Strong muscles, high agility, and quick reflexes require less energy than a complex brain, whilst still contributing significantly to the ability of a species to survive. Hence, unless conditions are absolutely ideal, there's little incentive for animals to develop the kind of intelligence that we've developed.

I'm not suggesting that humans perhaps aren't meant to be here. But I just think it's fascinating that we're so inconsistent with the rest of nature.

We might suppose ourselves the pride and joy of natural selection, but really that's only true insofar as we are capable of surviving longer than other species. Our bodies are so hopelessly adapted to hardship, that once our technological advantage is taken away from us, our prospects become suddenly very bleak. And maybe, if circumstances become extremely difficult to endure, we might just end up losing our big brains, and end up developing big bodies instead.