Egg fertilization is often described as an epic swim meet: Millions of sperm swim as fast as they can toward the egg until ...

All new babies start as an egg and a sperm, but where do those two cells come from in the first place? Your reproductive organs produce the sex cells that make a baby. Sperm cells begin their life ...

This sperm cell was then injected into an egg, resulting in the first-ever kangaroo ... and the embryo can go into suspended animation for several months," Gambini said. "Our success with IVF ...

As viewed from a human perspective, nature has done some ingenious engineering to overcome some of the obstacles it has faced. Take the evolution of sex, for instance. To make the move from ...