Evolution of sexual dimorphism

[larali]

Are clothes the reason for a greater sexual dimorphism amongst Northerners?

In hot climates where clothes aren't really necessary (i.e. Africa), sex can be determined by looking at a naked body. Where people are covered up, people would have to rely on facial features and body structure to determine the sex of a person. Am I right?

[Mans not hot]

Babe, you're hawt.

[Ivan Kramskoï]

I think it can simply be explained by sexual selection or the absence of it in some part of the world.