For K!P,

modern theory on why our eyes are white is that it's a useful adaption for hunting - it allows us to more easily communicate non-verbally using eye gestures. Yelling or waving arms are more likely to get you killed by a predator or starve to death through not catching prey.
This is a loose theory though as eyes don't fossilize.

A New Zealander here - we have a legal minimum wage and there is no tipping expected - if I get *AMAZING* service I *might* tip - but it is the wait staffs' job to serve food - retroactively bribing them to do their job well seems insane to me..like tipping a surgeon so that I get neat stitches on my operation. That being said, I would tip in the U.S. in most cases, as I know the crazy (to our eyes) system they have there. This seems a big shout that that system needs to change...