Two Better Than One?

Why do we have two kidneys, but just one heart? Wouldn't it make more sense to have extras of everything in case something goes wrong? Why can't we be like the lowly earthworm, with five different hearts? Or those girls with two bladders and two uteruses? Or that other girl with four kidneys? Some extras make sense -- for example, having two eyeballs gives us better, binocular, vision. The heart and brain have two parts each, of course, but each side has a different function. One chamber of the heart pumps out oxygenated blood, the other pumps in deoxygenated blood; and each lobe of the brain is responsible for different functions and operations. The liver regenerates, so need for two of those, and you can live without the spleen and gallbladder. But as for the double kidneys, we're not sure why one wouldn't suffice to clean the bloodstream, and why do we need two lungs? Rutgers University anthropologist Susan Cachel told Discovery Health the one heart/two lung system started about 300 million years ago, when we emerged from the muck onto land. For whatever reason, that's what we needed to survive on land, and it's remained the same ever since. Not a very satisfying answer, if you ask me, but there you go.

Related Posts

Happy Museum Day!
Happy Museum Day!
It's International Museum Day, and we're celebrating with our favorite museum friends at the Museum Store Association...
Read More
New Organ Magnets!
New Organ Magnets!
New organ magnets by I Heart Guts just landed in shop! Check them all out, new additions to the colon gift collection...
Read More
Award-Winning Uterus Backpack!
Award-Winning Uterus Backpack!
Our backpack is a 2024 National Parenting Product Award winner! What the judges had to say: "This will be a great pie...
Read More

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.