Its Time for Intelligent Design

[Music]

i’m an engineer

and one of the first examples of

engineering i can think of

something that happened in high school a

group of students including me

were asked to build a bridge between two

tables

using some saran wrap some newspaper and

some tape and not

a lot else we thought about it for like

five seconds

and we decided we were going to build a

bridge based on

newspaper triangles because we thought

those were very strong

and what we ended up making looked like

this as i think you can imagine

this paper bridge was not very good it

didn’t work at all

what i learned from this experience was

two things first off

making something that’s a good idea

making it robust

requires some thought secondly don’t

build bridges out of paper

it’s not the right choice and won’t work

well

fast forward to the present day i just

finished my phd at mit

in biological engineering so i don’t

build bridges

i build bacteria that work differently

and have

new functions often when i tell people

this

like my uber driver or my dentist

i get the response aren’t you playing

god

this is a really good question and i

often brush it off so

today i want to set the record straight

and i want to actually give an answer to

this question

biology is really beautiful and

wonderful and it’s inspirational

and it’s also imperfect like the paper

bridge

that i built badly in high school

biology isn’t robust

and it could be composed of better

materials

we can and we should make biology better

the first thing to know about

engineering living systems

is that it feels super different than

engineering anything else

biological engineering is like

discovering that a

super messy alien spaceship has like

crash landed on earth

and we need to go through every

component and backwards engineer it

so that we can understand like the

tiniest bit about how it works

and have some chance at managing to

change

what it does biological systems are so

foreign

so alien they work and are structured in

ways that are so completely different

than the way human engineered systems

are built

that it feels a lot like an alien

spaceship

and in fact that’s because biological

systems weren’t made by humans

organisms are absolutely the most

sophisticated machines we know of

and they came about after four billion

years

of random chance no humans

and it shows right in addition to the

beauty and wonder of biology

it’s also unfinished and imperfect

and today i want to talk about two types

of imperfection

in biological systems that are the same

as the problems with that bridge

i made in high school first biological

systems

are not always very robust and second

they could be composed of much more

suitable materials

so first i want to give you an example

of a

really really dumb mistake in the human

genome

that gives people cancer normal healthy

cells

have lots of little molecular machines

called proteins

that they use to do all the normal

things that cells need to do to be alive

there are proteins that replicate your

dna um there’s proteins in your eyes

that sense light

proteins in plants that help them absorb

sunlight

proteins they basically do all the

chemical heavy lifting

in in living systems proteins are

physically composed of a bunch of

building blocks which are called amino

acids

so to make a protein you string the

building blocks together

and that string will fold up into like

the functional version of the protein

that performs some sort of function

these molecular machines are so central

to having a happy healthy cell

that it’s super important that your body

is able to manufacture

them correctly and also pass on

instructions

for how to do that to your descendants

and

in fact your genome is composed of those

instructions each gene in your genome

encodes instructions

for how to make a protein when you go

out in the sun you get a sunburn

it will physically damage your dna

which sometimes will mess up the

instructions for how to make one of

these proteins

and and here’s where the problem comes

in one of the most

important types of proteins that

protects you from cancer are proteins

that basically do quality control

they double check to make sure the cell

is operating right

and protect you from cancer so mistakes

in the dna

for how to make those proteins those

mistakes are especially bad and

especially likely to cause you cancer so

over here on chromosome 9 of the human

genome there’s two proteins

both of them are essential quality

control proteins both of them protect

you from cancer

and there’s something like fishy about

how

their the instructions are written down

which is that the instructions are

written down like

on top of each other but offset by just

a little bit

using like physically the same piece of

dna

and that means that any mutation in that

part of chromosome 9 is super likely to

mess up

either one or both of these super

essential quality control proteins

in fact mutations in this area of

chromosome 9

cause lymphoma and carcinoma which are

both types of cancer

from an engineering perspective this is

just an infuriatingly bad mistake

just scooch one of the proteins over

like they don’t have to be encoded on

top of each other

in a genome that’s three billion bases

of dna long how can you possibly not

have space

to encode these two essential qc

proteins separately

to me this area of the human genome is

like

painfully embarrassing over billions of

years of evolution genomes will

accumulate these errors

it’s just heartbreaking because any

human engineer would catch this

no one would engineer this deliberately

it sucks because

this mistake has caused there to be a

ticking bomb

in the genome of everyone watching this

a ticking bomb that nature left us

as a present to discover and i think

this would be a note

i would thus put on the human genome

report card mostly good but also

gigantic mistakes

it’s quite a paradox there’s so much

beauty and

so many fantastically elegant solutions

that

nature has presented us but they come

alongside huge mistakes

things nature didn’t get around to

fixing and i think we

tend to hesitate to criticize biology

because of its beauty on the whole that

does us all a disservice

because we let our awe

of living systems prevent us from

recognizing that there are

fixable problems that we could improve

upon

and i think when people think about

human genome editing

they get really carried away in

contemplating the morality

of like parents editing their children

to be tall and blonde and good at

basketball

and that’s not what’s going to happen

human genome editing is going to be used

to correct

egregious issues with the human genome

that arose because

our genome is the result of 4 billion

years of random chance

in the history of the universe no one

has ever sat down

and been like how should this work what

would work well

let’s engineer this in a way that makes

sense and is a good idea

no one has ever done that and that’s the

person i want to be

i want to be the person who engineers

nice clean robust genomes and i want to

do it with some rigor

and really careful thought i want to add

some

intelligent design if you will into how

living organisms are built

so in fact during my phd i worked on

making biological systems better

i wanted to make a systematic change

that would allow biology to be more

extensible

one of the big limitations of biology

are the basic building blocks themselves

so there are only 20 different types of

amino acids and when you look at the

amino acids

chemically speaking they’re actually

kind of boring

like one very easy way to see this is to

look at them on a periodic table

out of all this good stuff only five

chemical elements

appear in proteins this would be like

if the alien biology spaceship landed on

earth and we find that it’s entirely

made out of

paper it’s perhaps amazing and

inspirational that they managed to get

so far

light years with so little but at the

same time like

maybe we could get some heavy metals up

here because they’re like good for

things

so in grad school i worked on genetic

code expansion

which is where we’re trying to expand

biology to include

more interesting building blocks that

have new properties i

told you before that genes write down

instructions for how to create proteins

and the way these instructions are

written is actually very simple

the gene is just composed of a list of

three-letter names or codons

for each amino acid in the order that

they should be added to the string which

will fold up into your protein

what i worked on during my phd is

creating bacteria that have

both a very simple and also like very

fundamental change

they use longer names to refer to

building blocks

so they use four base codons rather than

three base codons

longer names means more possible names

and thus more possible amino acids and

that would be amazing

do you want to make proteins that break

down plastic bottles

use new amino acids proteins that are

next generation versions

of therapeutics like insulin or

interferon

those can be improved again with new

amino acids

if you want to make new types of cancer

therapeutics

that aren’t possible today you have to

use new amino acids

expanding biology to be more chemically

sophisticated

this is the future and so to answer the

question i posed at the beginning

aren’t you playing god the answer is yes

we’ve been gifted with an amazing

starting point a natural world

that’s full of plants and animals and

people and now we can take it from here

we can take these systems and smooth out

the sharp edges

that nature didn’t get around to fixing

and we can make our own genome more

robust

in order to prevent cancer we can expand

the fundamental chemical basis of life

so that we can use biology to build

better stuff we can

and we should finally intelligently

design

life