All language subtitles for MIT700XXSP13-G010201-en

ERIC LANDER: But it isn't just medicine.

There are a lot of other things going on that touch other parts of society.

For example, something that I care a great deal about and was involved in

very early was DNA fingerprinting.

DNA fingerprinting, an application to the criminal justice system, where

it's possible using DNA to uniquely identify people.

And to be able to tell from a little bit of blood, or a little bit of spit,

or a little bit of semen who it was at the scene of a crime.

That's been fantastic in certain respects for being able to catch

people who were guilty parties.

It's also-- perhaps surprisingly to many people--

turned out to be incredibly important for vindicating people who were

convicted when in fact they were innocent.

It's taught us that the criminal justice system can be just plain

wrong, that the science is so clear, so sure that we know somehow that a

jury and a police made a mistake.

And more than 300 people have been exonerated because of molecular

biology, including 17 people who were on death row.

It's a pretty remarkable thing that the science can move to that point.

And other interesting things that we find out about history.

It's possible to complement everything that we've learned from archeology

with things that we can now learn from DNA.

We can look at the genetic makeup of people around the world, and we can

begin to trace back common ancestry.

Who migrated where from where.

We can trace back and figure out that the entire human population inhabiting

the world today migrated out from Africa within about the

last 100,000 years.

We know that, that we all have common roots back in Africa

100,000 years or so ago.

That's interesting because there were other human species on this planet

more than 100,000 years ago, occupying other niches around the planet.

And you can ask questions about those other human species, our relatives.

And in fact it's possible--

a friend of mine has isolated DNA from the bones of Neanderthals and is able

to ask the question, on our way out of Africa, did we ever interbreed with,

mate with, have some kind of a one night stand with a Neanderthal.

And the answer turns out to be yes.

It turns out, looking across the class here and everybody watching on the

web, about on average four percent of your genome is Neanderthal DNA.

And we know that.

You are part Neanderthal.

And we can tell those things.

And we tell about other things.

I've got to say, I've been teaching this course for 20 years, although

I've never been teaching on the web before, but I've been teaching this

course for 20 years, and all the things I'm telling you about were not

known when I started teaching the course.

That's what makes this so much cooler than introductory physics, where

virtually everything--

[LAUGHTER]

ERIC LANDER: I mean nothing against introductory physics, but virtually

everything you learn in introductory physics, it was some dead white guy in

the 1600s or something like that.

Or maybe the 1700s or something like that.

Whereas so much of what's exciting about what's going on right now is

going on right now.

There are remarkable things having to do with genetic engineering.

It's possible to add genes back to make transgenic plants

and transgenic animals.

And that's an incredibly powerful thing.

We can do that for medical purposes.

We can make a mouse that carries some mutant form of a gene and can become a

model for a human disease and study the basis of the human disease in a

mouse, rather than having to study that in a human being to start with.

You can make, for example, plants that are resistant to certain herbicides,

so that they can in fact grow better in certain types of field.

You can make plants, rice for example, that makes a lot of beta carotene.

When it makes beta carotene, that's a precursor for vitamin A, and many

people in the world are deficient in vitamin A. And when they're deficient

in vitamin A, they can go blind.

Being able to provide high sources of beta carotene, a pretty wonderful

thing in rice.

But it's also controversial.

There are people in parts of the world who are very bothered about the idea

of genetically modified foods.

I think some of that has to do with a lack of clarity--

is about what does it mean to do genetic modification anyway?

Is it dangerous in some way?

I think the more that we actually understand what genetic modification

is about, or what transgenesis is about, the more people can understand

it, the more people can make, I think, sensible, rational decisions about it.

But even beyond this kind of transgenic stuff, which has been

around now for about a decade or two, there's some really cool things that

have only been possible for the last several years.

It's possible right now to take certain genes, put them into nerve

cells, and be able to then, when they have the gene in them, which makes a

certain protein that's sensitive to a certain wavelength of light, fire

those nerves.

Fire those specific neuron cells by shining that light on them.

And not just shine the light and turn it on, but pulse, pulse, pulse, pulse,

pulse, pulse, pulse very quickly and fire these nerve cells at will.

That allows people to study the nervous system in mice, control all

sorts of behaviors and answer questions nobody's been able to answer

for a very long time, which is, what's this set of neurons doing, what's that

set of neurons doing.

And you can control them.

There are some pretty remarkable studies.

And you may think that's just an experimental thing, but imagine that

there's a human being who's blind because their photoreceptors somehow

don't work in their eye.

What if you could introduce that gene into their retina, and they could

suddenly again become sensitive to light.

Well there are people here at MIT working on such things.

There are people here working on ways of turning this from a discovery tool

into a tool for real therapeutics for people who can't see.

That'll take quite some time, but understanding those principles are

things we're going to do in this course as well.

Then finally to bring this up to date, this morning at 9:30--

I promise you this is current stuff.

This morning at 9:30, I was at a seminar at the Broad Institute--

where I'm the director--

and people were giving just a mind boggling talk that 18 months ago would

have been inconceivable.

They were talking about tools for going in and editing the genome.

Not putting in wholesale a whole gene but changing one single letter in the

entire genetic code of a cell.

One letter of your choice.

Being able to model a disease by changing exactly one letter or being

able to try to cure a disease by changing exactly one letter.

The paper describing how to do this came out about four weeks ago.

Four weeks ago.

It's pretty cool.

It's still an emerging technology.

It's pretty exciting where it's going to go.

But you should have the sense that this is changing under your feet.

This is changing as things go on.

Things that are just patently absurd and impossible today turn out to be

just hard a year or two from now, and turn out eventually to be a high

school lab project a decade and a half from now or something like that.

That's what modern biology is.

All right, so that's an introduction to the whole sweep of things that are

going on, what you should know about, what everybody should know about, and

really what I want this course to be about.

All right, so that's part one.

Before we go onto the next segment, test yourself with this problem.