Many state legislatures are seriously considering human embryos at the earliest stages of development for legal personhood. Total abortion bans that consider humans to have full rights from the moment ...

Add Yahoo as a preferred source to see more of our stories on Google. As an evolutionary biologist whose career has focused on how embryos develop in a wide variety of species over the course of ...

Who hasn't seen it before: the view through the microscope in which a sperm penetrates an egg cell and fertilizes it. This fundamental step in procreation happens dynamically and seemingly without ...

A pregnancy test detects the presence of the pregnancy hormone human chorionic gonadotropin, or hCG, in a person’s body. But the body doesn’t produce that hormone until several days after conception.

The majority of fertilized eggs die and are resorbed into the body. ZEISS Microscopy/Flickr, CC BY-SA As an evolutionary biologist whose career has focused on how embryos develop in a wide variety of ...