Smithsonian Innovations

Beth Shapiro Answers

admin — Tue, 22 Jan 2008 17:49:46 +0000

First, can we create Jurassic Park? From the perspective of a scientist working on ancient DNA, the answer is definitely no. Theoretical predictions based on the biochemistry of DNA predict that DNA fragments will only survive in ancient remains for around 100,000 years. But this doesn’t mean whole chromosomes, or even whole genes, but tiny, often highly damaged fragments of DNA. And even this is only in the best environments, such as very cold, very dry, and/or salty places. Most of our research depends on being able to find exceptionally well-preserved specimens, which means they must either be very young, or slightly older but from cold and dry places. In my own research, my collaborators and I focus on regions like the arctic permafrost of Siberia, Alaska, and the Yukon Territory. In those places we can find bones from animals that lived during the last Ice Age, such as mammoths, stilt-legged horses, steppe bison, short-faced bears, North American lions… and the list goes on. We then try to extract DNA sequences from the bones of these creatures or from the soil around the bones to learn something about what the environment was like at that time. We ask questions like: How big were the populations of the different species? Why did some species go extinct when others did not? How important was climate change, or human hunting, in the extinction of so many large mammals?

So, Jurassic Park is certainly out of the question. But what about Pleistocene Park? Well, I haven’t actually brought up all of the problems that ancient DNA research runs into. Because DNA starts breaking down immediately after the organism dies, the DNA fragments we can recover from these “ancient” bones and soils are not in good shape. The strands of DNA are damaged, broken, and balled up in ways that stop our lab techniques from working. In fact, ancient DNA studies normally rely on a particular type of DNA: mitochondrial DNA. The mitochondrial genome is separate from the nuclear genome, which is where most of the genes that make mammoths look like mammoths, for example, would be. Because there are many more copies of the mitochondrial genome than the nuclear genome in every cell, it is more likely that these fragments will survive in large enough quantities to be amplified. So, we don’t have very much information about the genes that make a mammoth different from an elephant, or those that make a North American lion something other than African lions. And even the mitochondrial DNA fragments that we can get out of these remains are small: normally around 100-200 bases long per fragment, whereas the entire human genome is more than 3 billion bases long. To cut the explanation short—we would need enormous technical breakthroughs to be able to recreate a mammoth or North American lion. We would need better techniques for extracting and amplifying DNA that would allow us to get both mitochondrial and nuclear DNA. We would need to be able to piece together the tiny fragments of DNA that we can amplify from ancient remains. We would need a way to line these up, package them into chromosomes, and package those chromosomes up into useful genetic material. Then we would need to find a host, work out the developmental differences and the list (again) goes on. We’re really not there. At least not yet.

Which brings me to the second part of my question, which in my mind is more important. Should we bring back extinct species, if there ever comes a point when we actually can? Is this the use of our financial and intellectual resources, or would it be a better bet to concentrate on, for example. conserving species and habitats that are currently under threat of extinction? What do you think?

Beth Shapiro Asks

admin — Tue, 22 Jan 2008 16:18:10 +0000

Can we create Jurassic Park?

Beth Shapiro: January 21-27

admin — Tue, 22 Jan 2008 16:00:23 +0000

Our next innovator is Beth Shapiro, a biologist at Penn State.

Michael Wong Answers:

admin — Mon, 14 Jan 2008 19:28:29 +0000

As I see it, the biggest environmental problem is contaminated drinking water. Solving this problem economically would have the greatest impact on the individuals and for our society. I emphasize economics because there are technologies out there now that can clean up water, but they cost a lot more than what people are willing to pay. Water treatment technologies that show better effectiveness and greater durability can address the cost issue.

Michael Wong Asks:

admin — Mon, 14 Jan 2008 17:16:51 +0000

If you could solve one environmental problem now, what would that be and why?

Michael Wong: January 14-20

admin — Mon, 14 Jan 2008 17:09:09 +0000

Our next innovator is Michael Wong, a tenured professor of chemical engineering at Rice University.

Learn more about Michael.

Kevin Kruse Answers:

admin — Mon, 07 Jan 2008 19:41:22 +0000

Franklin D. Roosevelt. He led the country through two major crises, the Great Depression and World War II, and in so doing thoroughly revolutionized America’s sense of itself, its purpose and its place in the world. FDR’s New Deal not only introduced the welfare state to America and radically changed the scope of government; it also reconfigured American politics, sparking 60 years of debate between those who sought to expand it and those who sought to roll it back.

Kevin Kruse Asks:

admin — Mon, 07 Jan 2008 19:39:36 +0000

Who was the most influential American of the 20th century?

Kevin Kruse: January 7—13

admin — Mon, 07 Jan 2008 19:36:00 +0000

Our next innovator is Kevin Kruse, an associate professor of history at Princeton University. Learn more about Kevin.

Aaron O’Dea Asks:

admin — Wed, 02 Jan 2008 17:13:46 +0000

What can the arts learn from the sciences and visa versa in today’s world?