My man's got a bad case of cystic fibrosis
A hella pessimistic prognosis
He started out like "why god, why god?
Why did that song have to shuffle on my iPod?"
Feelin' like he got struck with a left He did the sensible thing and read a textbook
And discovered an inherited disease
That can only be understood evolutionarily
He's got a gene called CFTR
With one deletion in a phenylalanine part
One less amino acid,
Fantastic
Hell-a-common,
One in thirty white people have it
Carry one copy and you don't even notice
Inherit two copies and catch a diagnosis
An autosomal recessive disorder,
One of more than
Four thousand genetic diseases recorded
And my man got the shorter side of the stick
So he started askin' questions like "why does it exist?"
What kind of sadistic joke is cystic fibrosis?
Now this is what he sings when he's feelin' hopeless
I live my life,
I love my friends,
I eat my food
Sometimes I just don't understand the things I do
A wise man told me:
"Look deeper inside you"
So now I take the gene's eye view
It turns out my man's got a special mutation
That goes back more than six hundred generations
CFTR is just one of twenty thousand
Protein-coding genes that have been accounted
Knock one out and it makes a vast difference
He can't breathe right,
And he's got no vas deferens
That's infertility without medical help
So how did this gene spread itself so well
That one in every thirty caucasian people have it?
He found the answer:
Heterozygote advantage
Two copies gives you cystic fibrosis
One copy protects you from tuberculosis
Mendelian diseases can spread because carriers
Get resistance to parasites like various
Malarias, just check out thalassemia
It's common in the tropics like sickle cell anemia
My man's mutation protected his ancestors
In times of pandemic it spread and became prevalent
So evolution sacrificed him for his relatives
And now this is what he sings when he's feelin' sick
I live my life,
I love my friends,
I eat my food
Sometimes I just don't understand the things I do
A wise man told me:
"Look deeper inside you"
So now I take the gene's eye view
My man studied evolution up to his eyeballs
Until at least he could say
"Hey, this isn't my fault"
It's all about trade offs and average benefits
Across populations;
Sometimes it's genetic drift
Or founder effects,
It's not always adaptive
Sometimes mutations just randomly happen
Sex chromosomally x-linked recessives
Only affect men and yeah,
That's kinda sexist
Some are autosomal dominant like Huntington's
Which only kicks in after reproduction's done
So selection can't eliminate it
Maybe human ingenuity can though;
It's innovative
Some disorders are so rare they're orphaned
And never get a piece of the research portion
My man's only one in three thousand
But in 2015 you can be one in three hundred thousand
And still be counted by patient advocates
Genetic research is takin' massive steps
My man's gettin' hitched and family planning
With his new gene's eye view understanding
I live my life,
I love my friends,
I eat my food
Sometimes I just don't understand the things I do
A wise man told me:
"Look deeper inside you"
So now I take the gene's eye view
I live my life,
I love my friends,
I eat my food
Sometimes I just don't understand the things I do
A wise man told me: "look deeper inside you"
So now I take the gene's eye view