5 Ways We Just Didn’t Evolve for This (Mismatch Diseases)


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!

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