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 ...

After ovulation, the egg survives for a very short time, yet this brief window plays a significant role in fertility.

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 ...