If you think the Clones on Star Wars were a threat, just wait until you hear about Asian clams.
Sure, there are physical differences but outside of mammals, the terms "male" and "female" take on different meanings.
Did you know that there are fish out there that can change sex?
Medically speaking, it's generally known that when it comes to being pregnant and giving birth, younger is better. Learn more on this Moment of Science.
According to a study, the longer it takes a woman to get pregnant, the greater her chances of having a boy.
Are whales ruining our environment? Find out on this Moment of Science.
Learn some fun and interesting facts about the human body on this Moment of Science.
Do sperm have noses? Find out on this Moment of Science.
Fraternal is when two different eggs are fertilized by two separate sperm. And even though fraternal twins can look very much alike, on average they only share fifty percent of their genes, the same as any other siblings.
Females also mate with more than one partner. Apparently doing this enables females to find partners with better genes or who are better providers.