A recent study came out which you can see here. It turns out the the offspring gets more of the mother’s genes than the father’s, a ratio of about 2:1.  Why so?  It’s because our ancestors long ago were not monogamous, at least the males weren’t.  Because the father’s didn’t have a concern to father children, it was to the advantage of later generations to instill monogamy.  Here’s a quote from the article:

Researchers report genetic evidence bolstering the socially contentious idea that polygyny—the mating practice where some males dominate reproduction by fathering children with several women—was the norm for sexual behavior throughout human history and prehistory. Because polygyny means other men father few or no children, the study, published today in PLoS Genetics, also shows that, on average, women bequeath more genes to their offspring than men do.

Interesting stuff.