By the way, simply stating that a certain trait could have resulted in a competitive advantage in a situation which you consider to have been relevant in evolutionary time is not a proof; it's a just-so story.
You might wish to make it clear that you are asking the question of the scientific profession, not of commenters here, unless you expect commenters here to go into the laboratory and the field and accumulate proof to substantiate their suggestions. I'm afraid there's not much better that we can do here except reference professionals who have done so. That's what Rachel appears to have done.