Evolution might be the reason why ladies "ain't messin' with no broke" fellas.

New research from the University of Michigan holds that men and women trade sex for resources, much like relations between penguins where females mate with the males who bring them pebbles to build their nests.

The study involved nearly 500 undergraduate students at the University of Michigan who—despite a lack of need for basic life-supporting resources—reported having thought about what they could give in order to have sex or what they could obtain from doing so.

Only a small percentage of students actually followed through or responded to these proposals Researchers were shocked that though the transaction approach is no longer highly effective in first-world society, thoughts of exchange provided proof that the biological urge for females to mate with the most eligible providers persists. And males are still motivated to offer possible mates funds, food, intellectual support, pebbles or, say, a shiny new diamond to secure a female's affections.

Read more about the study here.