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Interview with George Church

Can Neanderthals Be Brought Back from the Dead?

In a SPIEGEL interview, synthetic biology expert George Church of Harvard University explains how DNA will become the building material of the future -- one that can help create virus-resistant human beings and possibly bring back lost species like the Neanderthal.

Friday, 1/18/2013   07:41 PM

George Church, 58, is a pioneer in synthetic biology, a field whose aim is to create synthetic DNA and organisms in the laboratory. During the 1980s, the Harvard University professor of genetics helped initiate the Human Genome Project that created a map of the human genome. In addition to his current work in developing accelerated procedures for sequencing and synthesizing DNA, he has also been involved in the establishing of around two dozen biotech firms. In his new book, "Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves," which he has also encoded as strands of DNA and distributed on small DNA chips, Church sketches out a story of a second, man-made Creation.

SPIEGEL recently sat down with Church to discuss his new tome and the prospects for using synthetic biology to bring the Neanderthal back from exctinction as well as the idea of making humans resistant to all viruses.

SPIEGEL: Mr. Church, you predict that it will soon be possible to clone Neanderthals. What do you mean by "soon"? Will you witness the birth of a Neanderthal baby in your lifetime?

Church: I think so, but boy there are a lot of parts to that. The reason I would consider it a possibility is that a bunch of technologies are developing faster than ever before. In particular, reading and writing DNA is now about a million times faster than seven or eight years ago. Another technology that the de-extinction of a Neanderthal would require is human cloning. We can clone all kinds of mammals, so it's very likely that we could clone a human. Why shouldn't we be able to do so?

SPIEGEL: Perhaps because it is banned?

Church: That may be true in Germany, but it's not banned all over the world. And laws can change, by the way.

SPIEGEL: Would cloning a Neanderthal be a desirable thing to do?

Church: Well, that's another thing. I tend to decide on what is desirable based on societal consensus. My role is to determine what's technologically feasible. All I can do is reduce the risk and increase the benefits.

SPIEGEL: So let's talk about possible benefits of a Neanderthal in this world.

Church: Well, Neanderthals might think differently than we do. We know that they had a larger cranial size. They could even be more intelligent than us. When the time comes to deal with an epidemic or getting off the planet or whatever, it's conceivable that their way of thinking could be beneficial.

SPIEGEL: How do we have to imagine this: You raise Neanderthals in a lab, ask them to solve problems and thereby study how they think?

Church: No, you would certainly have to create a cohort, so they would have some sense of identity. They could maybe even create a new neo-Neanderthal culture and become a political force.

SPIEGEL: Wouldn't it be ethically problematic to create a Neanderthal just for the sake of scientific curiosity?

Church: Well, curiosity may be part of it, but it's not the most important driving force. The main goal is to increase diversity. The one thing that is bad for society is low diversity. This is true for culture or evolution, for species and also for whole societies. If you become a monoculture, you are at great risk of perishing. Therefore the recreation of Neanderthals would be mainly a question of societal risk avoidance.

SPIEGEL: Setting aside all ethical doubts, do you believe it is technically possible to reproduce the Neanderthal?

Church: The first thing you have to do is to sequence the Neanderthal genome, and that has actually been done. The next step would be to chop this genome up into, say, 10,000 chunks and then synthesize these. Finally, you would introduce these chunks into a human stem cell. If we do that often enough, then we would generate a stem cell line that would get closer and closer to the corresponding sequence of the Neanderthal. We developed the semi-automated procedure required to do that in my lab. Finally, we assemble all the chunks in a human stem cell, which would enable you to finally create a Neanderthal clone.

SPIEGEL: And the surrogates would be human, right? In your book you write that an "extremely adventurous female human" could serve as the surrogate mother.

Church: Yes. However, the prerequisite would, of course, be that human cloning is acceptable to society.

SPIEGEL: Could you also stop the procedure halfway through and build a 50-percent Neanderthal using this technology.

Church: You could and you might. It could even be that you want just a few mutations from the Neanderthal genome. Suppose you were to realize: Wow, these five mutations might change the neuronal pathways, the skull size, a few key things. They could give us what we want in terms of neural diversity. I doubt that we are going to particularly care about their facial morphology, though (laughs).

SPIEGEL: Might it one day be possible to descend even deeper into evolutionary history and recreate even older ancestors like Australopithecus or Homo erectus?

Church: Well, you have got a shot at anything where you have the DNA. The limit for finding DNA fragments is probably around a million years.

SPIEGEL: So we won't be seeing the return of the caveman or dinosaurs?

Church: Probably not. But even if you don't have the DNA, you can still make something that looks like it. For example, if you wanted to make a dinosaur, you would first consider the ostrich, one of its closest living relatives. You would take an ostrich, which is a large bird, and you would ask: "What's the difference between birds and dinosaurs? How did the birds lose their hands?" And you would try to identify the mutations and try to back engineer the dinosaur. I think this will be feasible.

SPIEGEL: Is it also conceivable to create lifeforms that never existed before? What about, for example, rabbits with wings?

Church: So that's a further possibility. However, things have to be plausible from an engineering standpoint. There is a bunch of things in birds that make flying possible, not just the wings. They have very lightweight bones, feathers, strong breast muscles, and the list goes on.

SPIEGEL: Flying rabbits and recreated dinosaurs are pure science fiction today. But on the microbe level, researchers are already creating synthetic life. New bacteria detect arsenic in drinking water. They create synthetic vaccines and diesel fuel. You call these organisms "novel machines". How do they relate to the machines we know?

Church: Well, all organisms are mechanical in the sense that they're made up of moving parts that inter-digitate like gears. The only difference is that they are incredibly intricate. They are atomically precise machines.

SPIEGEL: And what will these machines be used for?

Church: Oh, life science will co-opt almost every other field of manufacturing. It's not limited to agriculture and medicine. We can even use biology in ways that biology never has evolved to be used. DNA molecules for example could be used as three-dimensional scaffolding for inorganic materials, and this with atomic precision. You can design almost any structure you want with a computer, then you push a button -- and there it is, built-in DNA.

SPIEGEL: DNA as the building material of the future?

Church: Exactly. And it's amazing. Biology is good at making things that are really precise. Take trees for example. Trees are extremely complicated, at least on a molecular basis. However, they are so cheap, that we burn them or convert them into tables. Trees cost about $50 a ton. This means that you can make things that are nearly atomically precise for five cents a kilo.

SPIEGEL: You are seriously proposing to build all kinds of machines -- cars, computers or coffee machines -- out of DNA?

Church: I think it is very likely that this is possible. In fact, computers made of DNA will be better than the current computers, because they will have even smaller processors and be more energy efficient.

SPIEGEL: Let's go through a couple of different applications of synthetic biology. How long will it take, for example, until we can fill our tanks with fuel that has been produced using synthentic microbes?

Church: The fact is that we already have organisms that can produce fuel compatible with current car engines. These organisms convert carbon dioxide and light into fuels by basically using photosynthesis.

SPIEGEL: And they do so in an economically acceptable way?

Church: If you consider $1.30 a gallon for fuel a good number, then yeah. And the price will go down. Most of these systems are at least a factor of five away from theoretical limits, maybe even a factor of 10.

SPIEGEL: So we should urgently include synthetic life in our road map for the future energy supply in Germany?

Church: Well, I don't necessarily think it's a mistake to go slowly. It is not like Germany is losing out to lots of other nations right now, but there should be some sort of engineering and policy planning.

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