Risky sex... among Nile lechwe

According to a recent article in The Economist, the Nile lechwe (an endangered antelope) engages in risky sex--at least the female does. And, no, it's nothing kinky. But researchers have found that as the mothers age, they have a higher percentage of sons. Scientists have not figured out the mechanism behind this, but it is more clear cut evidence of how deeply sexual selection principles are hard-wired into us (including humans). In this case, the sexual shift appears to be a classic example of risk/reward. Almost all females reproduce, so having daughters is a good way to ensure genetic success. Sons are riskier. Only the more successful will mate, but they have the chance to pass along their genes to many more offspring. As female lechwe near the end of their lives, it appears that they are more willing to roll the dice on males, even though male births are also three times more likely to kill them. Apparently, once a female lechwe has neared the end of her ability to breed, she is willing to pay the ultimate price in an attempt to pass along her genes to a greater number of offspring.

Of laughter and marriage

Teasing is good for your relationship! That, at least, is what recent studies suggest. Researchers have discovered that married couples who have a lot of nicknames for one another are happier. In fact, teasing has been shown to help even during fights. This goes against the conventional wisdom of couples therapy, which often insists on discussing things in the most earnest tones imaginable. These findings go to the heart of one of the great paradoxes of relationships. Although they are incredibly important and serious, they do better when we treat them with a certain amount of playfulness. People always talk about working on a relationship, but that is often the wrong approach. When you think it's time to work on the relationship, that probably means it's time to play.

Sperm and superiority

The latest study offers an interesting twist on what women should look for in a man--good sperm. Okay, okay, I know the next question: how does one go about finding good sperm? Well, it turns out that all a woman needs to find is an intelligent man. A recent study discovered a clear link between intelligence (as measured by something called Spearman's g) and sperm quality. Since we are all shaped by sexual selection, this is not a shocking finding, but it does offer an interesting window into just how deeply that sexual selection has shaped our species. On first blush, most of us would probably assume that there were many good reasons for the development of intelligence that had nothing to do with attracting a mate. But this study suggests the possibility that we have put the cart before the horse. Perhaps sexual selection is actually the driving force behind the expansion in human intelligence, and the many other uses we find for our brains are actually just fortunate byproducts of that sexual selection. Who knew that dating might hold the key to human evolution?