Hi, my name is Ken Miller, and I want to talk to you today about
why evolution matters to biology, not just biology, but all of science.
I've got to start right up front by telling you that I'm not an evolutionary biologist.
I don't dig for fossils. I'm actually a cell biologist,
and most of my career has been spent working on the structure of biological membranes,
especially the photosynthetic membrane.
I use the electron microscope; that's where my training is.
I've used a technique called freeze etching to look inside those membranes,
and I've also used image analysis and reconstruction to develop things like
a 3-dimensional model of a photosynthetic membrane. This ended up on the cover of Nature.
And more recently my laboratory has also worked on the translocon,
which is a little channel by which proteins leave the ribosome and enter the rough endoplasmic reticulum.
So how does a nice cell biologist get interested in evolution?
There are actually two answers to that.
The first answer came from a student.
When I first began to teach at Brown University, where I still am,
a student came to me in the spring of 1981 and he challenged me.
He asked me if I wanted to debate a scientific creationist.
I had actually never heard of scientific creationism before
and the more I looked into it, the more I thought, "Yeah, I might like to go ahead and do this."
So the students ended up establishing and setting up a debate at my university.
To my amazement, an enormous crowd bought tickets to this event,
so many that we had to put it in the largest room on our campus
which was the ice hockey rink, believe it or not.
And I participated that year in another debate as well.
And in fact, in the two debates, in that year (1981), more than 3000 people showed up in aggregate.
I'd given scientific talks before, but I'd never attracted a crowd even close to that or seen that level of interest.
That made an impression on me.
That told me this was an important issue; one that people care about in the general public.
And also, I was appalled by the amount of scientific distortion
and misinformation that was garnished in the name of scientific creationism.
A second thing happened. Pretty much the same year, and that is, when the debates were over,
a former student of mine came to me with what I thought was an outlandish idea.
And that is: how about you and I get together and write a high school biology textbook?
Well, after a few debates, I decided that was over.
I sat down with my friend Joe Levine,
and Joe and I published a series of biology textbooks designed for high school students
that have been very successful and have been used through all parts of the country.
That's the second part of the story as to how I came to be interested in evolution.
Our books, being cutting edge biology, had a very strong treatment of the theory of evolution.
In some school districts, they were banned.
In other school districts chapters were cut out,
and in one, very important school district, a warning label,
which you can see right here, was actually placed on the surface of the textbook,
warning students that evolution was a theory and not a fact.
That brought me, in a way,
right back into the issue of whether evolution should be taught as part of mainstream biology.
Now a lot of my scientific colleagues ask me from time to time,
"Didn't we settle all this in 1925 during the Scopes so-called monkey trial?"
And unfortunately, I'm afraid, that what they're thinking of when they talk about this
is in fact the movie, Inherit the Wind, which is loosely based on the Scopes trial.
The reality is that when William Jennings Bryan and Clarence Darrow squared off
in that Tennessee court room, John Scopes was convicted,
and evolution basically disappeared from science textbooks in the United States for almost 50 years.
It's an extraordinary thing.
And even today, the anti-evolution movement in this country is thriving.
TIME magazine, several years ago, had a cover story on it. They called it the evolution wars.
Books, pamphlets, movies and even a museum have been opened to support the idea
that evolution is fundamentally wrong and that evolutionary science is completely mistaken.
This sort of activity led to a dramatic confrontation in 2005 in a federal court room
in the state of Pennsylvania after a town, Dover, Pennsylvania, decided to
order its teachers to prepare a curriculum on an anti-evolution idea called 'intelligent design'.
What followed was a dramatic and widely publicized seven week trial.
I had the honor, but I'm never sure if that's the right word,
of serving as the lead witness in that trial,
and what you see right here is actually the NBC TV court room sketch of my cross-examination
during the first days of that trial.
At the end of the seven weeks, what happened?
Well, the judge, actually a conservative republican,
appointed by George W. Bush, looked at the evidence and testimony and said,
"Intelligent design simply isn't science."
In my opinion, of course, exactly the right verdict.
And this was big news. It appeared on the nightly news on every one of the major networks,
front page of the New York Times, everywhere you can possibly imagine.
Now, despite this verdict as it turns out, or perhaps because of the verdict,
a lot of us who testified in the trial, and I was just one of several scientists who did that,
ended up with some very interesting requests when the trial was over.
I appeared on a couple of TV programs, here's a snapshot of one of them.
And those TV programs appeared on unlikely networks like Comedy Central.
And, yes, I actually appeared as a guest on the Colbert Report,
and if any of you listening to this would like to find a clip of that, it's really easy to do.
You just go to Google, and you type in my name and Colbert Report
and a couple of appearances on Colbert will come up.
It was an extraordinary thing.
It got, I think, the message of science across to an audience that normally wouldn't get it.
But something interesting comes out of that,
and that's one of the key points that I want to make.
All too many of my colleagues in the biological science community think that
evolution's just a story about the past, and therefore defending evolution is the job of
paleontologists and fossil hunters and that sort of stuff.
But the reality of science today is that evolution is everywhere.
It's even in our blood, and because it's in our blood, it's in our genome.
Now, what I've put up here is an image showing hemoglobin,
the red protein that carries oxygen in our blood stream.
We know the exact location of the genes for alpha and beta globin on the human chromosome,
and there's something very different and very interesting about their structure and organization.
We actually have five copies of the gene for beta globin.
We use this at different times in our life cycle.
They were all produced, any evolutionary biologist would tell you,
by the process of gene duplication, but here's what's really cool.
Right in the middle of this collection of genes, and you can see it right there,
is in fact a pseudogene. You can see the Greek letter psi above it.
That means it's a gene that is broken. Now why do I say it's broken?
It means that one of these multiple copies
accumulated so many mistakes that it couldn't work anymore.
What are the nature of the mistakes? You can see them here.
They involve altered control regions, frame shift mutations.
Even if this piece of DNA could be transcribed,
it could never be translated; it could never be made into a protein.
Now, why is all of that significant? It's significant for a very simple reason.
Mistakes are unique. They occur only once, and then they're propagated to
all of one's descendants, and that's what's happened with the beta globin pseudogene.
But, the interesting part is that we share not only the structure of this beta globin locus,
but we also share those mistakes with three other organisms.
Want to know who they are?
They're the gorilla, the chimpanzee and the orangutan.
And what does that mean? It means that all four of these species,
these three guys and us, share common ancestry.
And our genome is testament to that. But, there's even more.
As a cell biologist, I've worked prety much my entire career on organelles within cells.
Two of the most interesting are chloroplasts and mitochondria.
And my lab has done some research on both.
These are extraordinary organelles that are involved in the transduction of
either chemical or solar energy into a form that the cell can use.
Now there are some weird things about these two organelles.
One of them is: they both import proteins from the cytoplasm (the rest of the cell).
Now, that's not surprising, but they import them, take them inside,
and then re-export them into their own membranes.
It's sort of a roundabout route.
It's like going to one side of the shopping center and then the other,
and then coming back in and then going back out again.
It makes very little sense.
It also turns out, they're both surrounded by two membranes.
Most organelles of the cell-only one.
How come two? It's a bit of a puzzle.
Another thing is they are not made by the cell from scratch. They're self-replicating.
In other words, they come only from the division of pre-existing mitochondria and chloroplasts.
In addition, the ribosomes, the protein synthesizing machines, within these are distinct.
They're very different from ribosomes from the rest of the cell.
Why should these guys have their own unique ribosomes?
And last but not least, they've got their own DNA.
They have their own genetic systems.
Why is all of this the case?
Well, the answer, from evolution, turns out to be very clear and very straightforward.
Mitochondria, there's very clear evidence, arose from primitive bacteria
that were then taken inside an early eukaryotic cell and then surrounded by a second membrane
and eventually formed into the organelles that today we call mitochondria.
Chloroplasts are pretty much the same thing,
except it was a cyanobacteria (a photosynthetic prokaryotic organism).
And once you understand this process, which is called evolution by endosymbiosis,
everything makes sense, protein import and re-export, the double membranes,
the self-replication and the unique ribosomes, and the fact that these organelles have their own DNA.
It all fits together, and it fits together quite beautifully.
Today, evolution itself is a research tool.
We use evolution to understand the relationships of proteins in the cytoskeleton, for example.
We also use evolution to understand the development of body plans
in the field of evolutionary developmental biology.
If you want to read up on this, pick up Sean Carroll's great book, "Endless Forms Most Beautiful".
And in this, Carroll explains the way in which the animal body is modular.
It's made up of repeating parts and these repeating parts
basically produce the forms and patterns that we look at and appreciate as biologists.
Now, one of the problems that I see as a scientist and an educator is
that evolution acceptance in this country is near the bottom of the industrialized world.
There were 29 countries polled in which a larger proportion of their citizens
accepted the theory of evolution than in the United States.
We're at the bottom of that list. The only country we beat out in Western Europe is Turkey.
Why is that? I think in large measure that's because
evolution is presented as a fearful doctrine, as something to be afraid of.
And that fear that characterizes, or the induction of fear that characterizes
the anti-evolution movement is dangerous.
Not just because it might cause people to reject evolution,
but rather because it might lead to us raising up a generation of young people
who have been taught that science is to be feared and distrusted.
And if we do that, this country will give up world scientific leadership,
something that we simply cannot afford to do.
In fact, in the current year, 2011, anti-evolution measures have actually
been introduced and attempted to be made law in no fewer than 7 state legislatures.
I'd like to pretend this is in the past, but it is in fact an ongoing problem.
So, what do we make of this?
Defending evolution is really defending the scientific method.
It isn't about Darwin anymore. It's about the science that we do today.
And I think every member of the scientific community
whether student, post-doctoral researcher, faculty level researcher or independent scientist,
owes it to themselves to defend evolution for two reasons.
One is, it is the unifying principle that makes sense of everything we do in biology.
And number two, acceptance of evolution means acceptance and embrace
of science and the scientific method.
Nothing could be more important for the scientific enterprise,
and in my opinion, nothing could be more important to our country.
Thanks for listening.