When Did Our Ancestors Stop Laying Eggs?

You could have been born weighing a few grams and as big as a bean or yuckier from a soft-shelled egg...But instead of carrying you into a marsupium, your mother delivered a 3-5 kg (8-13 pounds) hunk, resembling a human being (more or less). That's because she fed you through an organ c... [ read more >> ]

A human placenta

Image comment: A human placenta

A human placenta