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Foreign Life on Earth

April 3, 2012

Is there “foreign life” on Earth? That is a question posed this week by Nature. Foreign life–in the sense of a new, fundamentally different and unpredicted kind–has emerged more than once in human history. Leeuwenhoek’s microscope in 1673 revealed new life all around us; life so terrifying that his neighbor had all their teeth pulled to get rid of the teeny bugs. In 1964 Woods Hole’s Alvin first voyaged to the deep and discovered hydrothermal vent creatures–at huge pressures and high temperatures–breathing hydrogen sulfide to feed their symbiotic bacteria. And in 1977 Carl Woese discovered Archaea, a third domain of life equally distant from bacteria and eukarya (nucleated cells). Archaea were first thought to live only at extremes, but today we find them everywhere, in soil and water, and in our own gut flora. And amazingly, none are yet known to cause disease.

Since, with Tea Partiers running amok, we’re unlikely to pay for health care let alone visit Mars, restless adventurers look inward: Back to the deep with Cameron, and where else?

Perhaps, like archaea, yet another “domain” could emerge all around us. Something so foreign its DNA doesn’t show up in our PCR profiles. Poignantly, even our plans to detect Martian life seem to assume resemblance to that of Earth. But even on Earth, as on The Children Star, there are suggestive signs of another presence. The inhospitable desert produces desert varnish, a mysterious rock coating rich in manganese that might have been put there by some kind of microbe. And what about crustal rock, miles down? As far down as we look, we find microbes–and they’re not the kind we expect. What if there are kinds we don’t even find?

I still say the real foreign life is virtual, the “PC viruses” that mutate and evolve. And the next will be smart sand creating its creators. What do you think?

  1. April 4, 2012 10:41 am

    I think the real foreign life will be artificial, biological life. There are so many interesting experiments on biology, from stripping down the genome to essentials, to adding entirely new functional proteins and control systems via synthetic genes to re-engineering the genetic code. Some of the biology will turn out very different than anything we have seen to date.

    There is also a small chance that there is a “shadow biology” on earth, populated by single cell organisms with very different biology. But so far this is just speculation.

    • April 4, 2012 7:52 pm

      “Artificial life” will likely have interesting functions for human technology, including thinks we can’t imagine. But new life interesting in itself–more so than what’s evolved in nature? More wild than Featured Creature? I’m skeptical of that.

  2. April 4, 2012 3:11 pm

    Personally, I tend to think the next frontier is the soil. When I was counting fungal spores for my PhD, I had a whole beastiary of things I couldn’t identify even to phylum. Some of it was spores and pollen, some testate amoebas but much of it I never did figure out.

    Every mycorrhizal researcher I’ve talked to has a similar collection of unknown mesobiota, many hauled from vacant lots, old fields, and similar ordinary places.

    Of course, it’s more romantic to go to Antarctica to look at soil mesobiota. Still, I’d say look about 6 inches down in your back yard, first. Or if you can find a remnant prairie, all the better.

    • April 4, 2012 9:47 pm

      Didn’t I read somewhere (a few years ago?) that one of the world’s most expert mycologists retired/died a few years ago, and no one was interested in doing fungal classification work any more? It was going to become a lost expertise.

    • April 5, 2012 12:16 am

      Actually, it’s always been a rare expertise. There are often only a few people who are expert in a particular group of fungi. I used to be one of those people, but I’m waaaay out of practice.

      It’s actually normal for many unusual organisms that one or a few people are the experts. For example my mother, an amateur botanist with no formal biology training, is one of the world’s experts on a particular rare plant species. She got involved with it due to a legal action, started surveying the populations, and now knows more about it than just about anyone else.

      Where it gets sad is with things like the ~800 species of Drosophila fruit flies other than Drosophila melanogaster. Only a few old researchers actually knew how to identify these species, and about a decade ago, they held a special seminar to train another generation, so that their knowledge wouldn’t be lost. Considering how important Drosophila is in modern genetics, it’s saddens me that all their relatives are basically unknown. Many of them are quite rare, too.

      I could go down a very long list, but the end result is that expertise is actually pretty rare, and it can easily be lost.

  3. April 4, 2012 7:56 pm

    I’d like to see some of those fungal spores and testate amoebas. Any good pix? Have to revise my microbial eukaryotes chapter this summer.

    Mycorrhizae are interesting; and of course, whatever’s below foot in the soil. Every cubic centimeter of soil contains unknown species.

    But still, aren’t they all Bacteria, Eukarya, or Archaea? Or maybe “deep branching” somethings inbetween?

    What I’d like to see is RNA cells, or maybe prion life.

    • April 5, 2012 12:18 am

      Mycorrhizae are all fungi, by definition. I was counting and identifying their spores as a way of studying mycorrhizal diversity, and I’ll be happy to send you some pictures. What’s the capacity of your inbox?

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