Here at BrainPOP UK we like to encourage an inquiring mind and we get a lot of letters to Tim and Moby asking questions.
Sometimes when we get letters those questions get made into a movie, sometimes Tim and Moby write a letter back, and sometimes they even end up on the wall at BrainPOP HQ!
Today, we got a really great one that we couldn’t help but share. So, without further ado, here is Jowen’s fantastic question and Tim and Moby’s answer:
There are a few different reasons why we don’t have a part of our skeleton protecting our bellies, or abdomen.
Firstly, during pregnancy a woman’s organs need to be able to move out of the way of the foetus (that’s what a baby is called before it’s born) and her abdomen needs to be able to swell as the foetus grows. If there was a part of your skeleton covering that part of the body this wouldn’t be able to happen so there would be more risks for the mother.
On top of that babies would have to be born smaller and less developed due to the lack of space so they would have a lower chance at survival at birth. To learn more about pregnancy’s effects on women and how babies develop check out our pregnancy and foetal development topics.
Secondly, one of the skeleton’s main functions is support. Our skeleton helps hold us up and lets us move around.
If our rib cage extended down over our midsection then it could affect our ability to bend over, squat, sit down and other similar kinds of movements. Watch our skeletons topic to find out more.
And the rib cage has another job too. In tandem with the diaphragm the rib cage helps us to inflate and deflate our lungs so we can breathe.
We don’t need to do that over our stomach and if we had some parts of skeleton attached to the bottom of the rib cage it might make it more difficult to breathe. You can check out our respiratory system topic to find out more about how we breathe.
Genetics are a complicated business and sometimes a mutation that has an evolutionary advantage like for example resistance to malaria can have a big evolutionary downside like sickle cell anaemia.
So, it’s hard to say whether a mutation that led to a rib cage around the abdomen would have other side effects. Take a look at our genetics and genetic mutations movies to learn more.
Fundamentally, we don’t have skeletal protection for our stomach and intestines because not having it didn’t stop us from surviving.
To find out more about evolution and how it works check out our topics on natural selection, and human evolution.
Hope this helps and happy BrainPOPping!
Tim and Moby