I’ve long enjoyed the fact that there’s an evolutionary explanation of why trees do such a good job of providing shade. The function of leaves is precisely to catch the sunlight, and any sunlight that gets through to the ground is a missed opportunity.

Natural selection helped me out in another similar way just now. I was cleaning up the hallway after a visiting upholsterer left some duck feathers on our floor. Nothing is easier, I dicovered, than vacuuming up duck feathers! A little thought reveals that this is because evolution, as it were, has optimized duck feathers precisely for vacuumability: they are designed to be as light, and as good at catching the breeze, as possible.

[14 October 2014]