Let's begin with medicine from back in the day
When a priest and a medicine man were the same
I'm in pain, I've got a fever and I'm restless!
"A classic case of demon possession
I've got the cure though, here, take it easy
Drink this broth,
It's made from endangered species
It works only when the weather's not stormy
Now go sacrifice a goat and call me in the morning"
We practice medicine in similar ways today,
But now it's nominally evidence-based
It used to be entirely mysterious but these
Days it's just mysterious to various degrees
Thanks to Louis Pasteurization, vaccines
And discoveries like the germ theory of disease
But what about natural alternative medicine
Ayurvedic homeopathy and all the rest of it?
Well, if we can isolate and test it for effectiveness
Maybe some of it will be vindicated by evidence
And then it won't be "alternative",
It'll be "medicine"
And whatever's left?
Well, that we can jettison
Yeah, modern medicine is mechanistic
Treats the body like a machine,
Attempts to fix it
But the picture's incomplete without this next bit
Not just "how it works" but "why we get sick"
Why we get sick
We evolved to crave salt, sugar and fat
They were scarce in the past
So we get sick
Sit down,
Take some weight off
Lower back pain results as a trade off
We get sick
The genes inside us are ancient,
Surrounded by modern products
We get sick
Microbial arms races
Charles Darwin taught the basics
Of why we get sick
"Why does disease exist?"
Next time someone asks that,
Don't plead the fifth
I know your neighbour's car has a Jesus fish
You wanna keep the peace,
And he believes a myth
But so what?
People die from untreated infections
And asking "why" implies natural selection
And that can lead to new research questions
So lives are lost to avoid bein' offensive?
Well that's offensive
To life's preservation
Every disease requires two explanations
The first one is proximate,
Doctor Gregory House
Tryin' to get the diagnosis and figure it out
What's the broken mechanism?
Like a puzzle to solve
The second question is: How did this evolve?
Relax,
Evolution is so simple
The DNA in your cells encodes info
For how to build a body to develop and thrive
Ultimately to reproduce and survive
So disease itself is not the adaptation
But you need adaptations to explain...
Why we get sick
We evolved to crave salt, sugar and fat
They were scarce in the past
So we get sick
Sit down, take some weight off
Lower back pain results as a trade off
We get sick
The genes inside us are ancient,
Surrounded by modern products
We get sick
Microbial arms races
Charles Darwin taught the basics
Of why we get sick
How does DNA make design?
With no intelligent mind?
It takes time
But any variation that increases reproduction
Or random mutation that enhances some function
Of feeding or developing or escaping from hitches
Will tend to increase in number – that's fitness
Take infection, you can feel it, something's wrong
But that's an organism trying to get its reproduction on
Up in your guts,
No guts no glory
That's just one of several evo-categories
Another is defenses,
You catch a fever
To cook the invader,
No bug, that's a feature
Yeah, you have weapons to beat back infections
So don't make rash decisions and mask symptoms
Dosing with iron when your blood is busy bindin' it
And watch out for mismatched environments
We evolved in the days of the cave man
Coca cola wasn't really part of the game plan
And some diseases are all about genetics
You gotta take the gene's eye view to really get it
Sometimes they go rogue,
It's like starting a war
They send you to the oncology ward
Life is full of design compromises
Trade offs, you know,
Kinda like with high rises
Strength for tensility,
Speed for longevity
Live fast, die young,
Breed prolifically
And yeah, humans are still evolving
But we've got a body plan,
So we can't evolve wings
We had to wait to fly 'til someone thought of it
Cultural evolution, medicine is part of it
Cultural evolution, medicine is part of
Part of cultural evolution
Medicine is part of
Why we get sick
We evolved to crave salt, sugar and fat
They were scarce in the past
So we get sick
Sit down, take some weight off
Lower back pain results as a trade off
We get sick
The genes inside us are ancient,
Surrounded by modern products
We get sick
Microbial arms races
Charles Darwin taught the basics
Of why we get sick