How did evolution miss flat feet?

[Physics_wiz]

It seems to me that people with flat feet should have been weeded out by evolution back in the day when they actually had to walk and run around all day long. Am I missing something? Aren't people with flat feet at a huge disadvantage in those conditions?

 

[jim mcnamara]

Humans and most species have traits that appear to be non-adaptive.

One simple explanation is that non-adaptive recessive genes may be adaptive in the heterogenous state - i.e., the recessive combined with some other dominant gene provides a selective advantage.
See 'Sickle Cell Anemia' in Wikipedia for example.

The other reason is that (assuming falt feet represent some expression of recessive traits) that even recessives that are selected against stay in a population because when they are in carriers they have no selective effect.
Read about 'Hardy-Weinberg Equilibrium'

I do not know of any research on flat feet in humans. However it may be a trait that has selective advantages in some environments. Sometimes the obviousness of a genetic advantage is very hard for us to see. Mainly because we operate personally in an environment where it doesn't provide any advantage.

 

[selfAdjoint]

The existence of flat feet provides a class of people who will seek their livelihoood in some field where they can sit down. And from flint knapping to constitutional law, those activities have been adaptive for the band, tribe, or society.

 

[Phobos]

when they actually had to walk and run around all day long.

Was this ever the situation? The few remaining non-technological tribes of humans in the world don't do this. Granted, there are instances of this (e.g., prolonged hunts, nomadic migration), but as social creatures, we help each other out.

 

[Pythagorean]

It seems to me that people with flat feet should have been weeded out by evolution

couldn't flat feet be considered evolving for pavement walkers? Our feet aren't designed for flat surfaces, but we continually walk on them in western civilization, so it kind of makes sense to me. Maybe we need more innovative floor/sidewalk designs.