Ever wondered why our early ancestors were able to have so many kids? Well, it was because most of them were apparently active fathers, claim researchers. Northwestern University researcher Lee T. Gettler suggests in a new anthropological model of human evolution that the fathers among our earliest human ancestors may have helped jumpstart human evolution by helping females out with their children. Lee believes that the same paternal investment pattern resembles the kind of hands-on parenting many dads still display. "Other men might have been highly involved with direct care, engaging in behaviors not unlike what involved fathers do today,"...