this is an Australian Jewel Beetle and it's brown and shiny and it likes to
spend its time trying to find other shiny brown beetles to mate with which
was a problem when Australians started throwing out these Brown beer bottles
they call stubbies because they're brown and shiny and the beetles were trying to
mate with them, which as you can imagine doesn't end up producing a little baby
beetle and these beetles are actually having a problem with their reproduction
and with their populations now before you go on and on about how stupid
these beetles are not knowing how to live in the modern world - humans are
actually kind of doing the same thing but not with beer bottles I'm Kurtis
Baute, and welcome to the Scope of Science now today we're going to talk about five
ways that humans just didn't really evolved to live in the modern world. When
the way something has evolved doesn't match up with its current environment we
have a name for that we call it an 'Evolutionary Mismatch' today we're going
to talk about five of them in humans. When I was a kid I had two teeth that I
had to get removed because they wouldn't fit and then I had to get braces to get
everything else adjusted you may have had a similar experience or he may have
had wisdom teeth that you needed to get removed now why don't those teeth just
fit in our jaw like they should, I mean if you think about it back in
prehistoric times having a problem with your teeth well that could kill you. You
could get an infection or the pain could be too much that you wouldn't be able to
chew and you wouldn't be able to eat. So, how come we have this problem if we've
been evolving for billions of years you see our jaws evolved to be able to
chew a lot of food because we didn't have processed foods and before that we
didn't even have cooked food so our jaws didn't evolved for what we now eat, which
means that we're chewing less these days. And since we chew less our jaws don't
develop to be as big which means we don't have as much space for our teeth.
Thankfully now we have dentistry and we can actually get rid of these teeth
these extra ones without killing people, usually.
the most common reason for an elderly person to break a bone is called
'osteoporosis' and that's caused by the fact that we don't use our bodies like
we used to. We are more sedentary than ever before and since we're not
impacting our bodies as much and using our bones and muscles as much when we're
little our bones don't develop to be as strong as they need to be. That's what
normal bones should look like but when we don't use them enough they end up
looking like this and those bones are more likely to break.
So yeah evolutionary mismatch can cause broken bones. Number three: myopia most
oftenly called nearsightedness now this may surprise you but we didn't evolve to
be watching YouTube and reading books all the time as we develop and we spend
more of our time reading screens close up that development actually changes how
our eyes are formed and how the muscles in our eyes function meaning that when
we get older we need to have glasses to be able to correct our vision now it's
great that we can correct our vision in the modern era using glasses, and laser
eye surgery, and contacts, but it's possible to just avoid getting
nearsightedness altogether in a lot of cases just by making sure that young
people get an equal amount of exposure to the outdoors where they have to see
far away as they do seeing things close up like on YouTube. Number four: many
forms of cancer are actually mismatch diseases at least in part.
Take for example skin cancer. Now we live in a time where you can just hop on a
plane and move practically anywhere and your body may or may not be able to
naturally withstand the sunlight in that new environment. Now if you get sunburned
regularly that affects your DNA and you can eventually develop skin cancer from
that. So wear sunscreen! For women having fewer children increases your risk of
developing ovarian cancer and we live in an age and a culture where it's okay and
I'm not saying it's not - it is okay to have fewer and fewer kids and a lot
of people don't even have kids but that actually does affect their risk of
developing ovarian cancer. Now this one's a little more tricky as to what do we do
about it we can't just put on sunscreen I'm not saying that women should be
pregnant all the time I'm just saying it's a case of evolutionary mismatch
like it or not. You may have seen images like this comparing the Big Mac
super-sized era to 40 years ago when our pizza and our Big Mac was much smaller
but this is still way out of proportion with how we actually evolved. We
evolved so that during times of plenty we could build up energy stores so that
we can make it through those harder times so we really developed a sweet
tooth and we really love to eat calorie rich food, and sugary, salty food. Obesity
is on the rise in every country in the world and in America it costs 147
billion dollars a year in medical expenses expenses that wouldn't
otherwise happen. Our bodies evolved to eat calorie rich food but it didn't
evolve for a time when calorie rich food was basically limitless as it is today
or for a time when we are more sedentary than ever we spend most of our time
either lying down asleep or sitting at a desk and that's just not the same as
eating a small amount and running across the Sahara Desert. in David Lieberman's
book the story of the human body he talks about how evolutionary mismatch is
actually a very big and important deal for medicine because so far we've just
really been trying to treat the symptoms of all of these diseases we can get rid
of wisdom tea or we can just give kids sugar-free gum and as they're developing
they'll choose more and we'll use their jaws more and by doing that they'll be
less likely to have a problem with wisdom teeth
at all. I hope that in my lifetime we can cure cancer but it would be really nice
to prevent people from getting skin cancer by making sure they wear
sunscreen there's so many ways that we can prevent these evolutionary
mismatches from affecting our health and our well
being but to do it we really need to start taking more of an evolutionary
perspective on our health and on medicine. If you find things like
evolution and medicine and health interesting I recommend this book it
will give you a good sense of the story of human evolution as well as all of
these weird phenomenons called mismatch diseases. I've named five but the list is
gargantuan there are so many of these mismatch diseases. So, please check out
the book and if you think some of this is controversial
I'm sure actually a lot of it is I'm not going to get into that in this video you
can read the book it covers some of that but if you just want to chat leave some
comments in the comment section below I'm curious to hear what you think about
this. On The Scope of Science I regularly release videos about plants and rocks
and evolution and space and all sorts of science topics so if you like that kind
of stuff consider subscribing, and thanks so much for watching!