Evolution of Evolution — Text-only | Flash Special Report
Interview with John C. Priscu
What do we know about evolution that we didn’t know in Darwin’s time?
What we know today about the species and evolution following Darwin’s time, that there’s a genetic selection and adaptation by organisms to evolve into various niches, and his work on the Galapagos Island really, really showed that.
Darwin speculated life began in a "warm pond," but you believe it was a cold one?
I think Darwin, his little “warm little pond” idea was outstanding and way ahead of its time, firstly. I believe that he was thinking that pond in terms of a biogenic molecules are precursors to life. If you get warm or hot conditions, a lot of those precursor biomolecules don’t last very long, and when you want – when life originates, it’s a probability that you want to put things together, these cyanide and formaldehyde and methane together for a little longer, more than hours to minutes, you want them together for years and when you go to a colder environment, you can do that. You can keep things together for decades, hundreds of years, in a colder environment.
If nothing grows in Antarctica, how could life begin in similarly cold climates?
Our research over the last 25 years has now shown that the continent is not devoid of life. We’re finding microorganisms, and it’s not charismatic megafauna we’re talking about, it’s microbial life, and that’s – when we talk about origins of life, it’s microbes we’re talking about. They were the first life. They’ve been around three and a half billion years. The emerging picture is there’s huge rivers under the ice sheet and lakes under there, some of the largest lakes on our planet under there, Lake Vostok being the largest we know about. So, it’s not devoid of life and this life has been on the continent for a long, long time.
Will more samples from Lake Vostock give us clues about the origin of life?
I think we’re going to find a huge biodiversity of organisms. Now, we have two samples, really, in the whole continent of Antarctica. We have several – two samples that I know of that have come from the bottom; one from West Antarctica and there were as many bacteria per gram of soil as you see in farmland. It was just amazing, and then the work we’ve done, in my lab, on the Lake Vostok system is showing that that lake has as many bacteria in it as we would see in the open ocean.
What will be the next big discovery in Polar Sciences?
The next big discovery in polar researches is going to be that the ice sheet is alive. It’s a living ice sheet. It’s full of organisms that are cold-loving organisms, we call psychrophiles, and these organisms do not make a living with light. They don’t live with photosynthetic energy, but they eat rocks. They work on weathering products of the minerals so that’s where they get their energy, and the carbon CO2. I think that’s going to be our next big discovery in the next five or ten years and that discovery has global implications because if we do find it, it’s going to – our estimates show that the Antarctic ice sheet will then contain a pool of organic carbon, biological organic carbon, bacteria, that rivals – it actually exceeds all the surface lakes and rivers on our planet and starts approaching soils in temperate regions. So, I think that’s the next big discovery.