There's a curious puzzle unanswered by the theory of evolution: why do some animals give up their chance to reproduce to help others reproduce instead? For decades biologists have suggested family was the reason, but that has recently been challenged.
Learn more about advertising on the HowStuffWorks podcasts at www.howstuffworks.com/advertisers.htm
And to learn about your ad choices when listening to podcasts, visit
https://www.howstuffworks.com/privacy.htm#ad-choices
