Do eggs prefer one sperm over another?

You might think that when you’re choosing a partner to have children with that your decision is entirely yours. However it turns out that biology has an interesting trick up its sleeve, which may surprise you. It turns out that there are guidance mechanisms that, like homing beacons, can help swimming sperm get to the eggs. It’s because cells in women’s bodies release special attracting chemicals into the fluid surrounding the eggs, and, according to a recent paper, these chemicals seem to prefer some sperm over others, taking the decision making completely out of your hands! In reproductive biology circles, it’s called cryptic female choice. And as Katie Haylor found out from Stockholm University’s John Fitzpatrick, the cryptic nature of this choice is becoming a little clearer….

Reference -Chemical signals from eggs facilitate cryptic female choice in humans