|
Subject: Viridian Note 00355: More Biosphere Bugs
Links:Oliver Morton. It hasn't escaped my attention that this subject has some pulp science-fictional aspects. http://www.ditko.comics.org/ditko/covers/marvel/jim058.htm Those strange AMODA people are gonna be playing
their "music" here tonight. The electronic-art installation is still running here, too. (((As we were remarking earlier in the most recent Viridian Note, 00354:))) "Consider the following, and the possible interconnections here. "A: Michael Russell's theory that single-celled life was formed, not in open seawater, but in water-soaked iron sulfide rocks in hydrothermal vents. Mineral 'cell walls' formed first, and then self-replicating chemistry formed within these tiny stone pockets. If this is true, then most rocky planets might have formed chemosynthetic life deep underground, wherever hot water oozes through chemically active rock. "B: NASA/Stanford suggests possible fossil Martian microbes in Antarctic meteorites. "C: Dirk Schulze-Makuch says there's an odd chemical imbalance in atmosphere of Venus, which could be caused by sulfur-metabolizing bacteria, living in damp, pleasant temperatures in high Venusian clouds. "D: Oliver Morton's ideas that Earth's cloud formation involves ocean bacteria nucleating ice crystals. As Morton puts it, 'Clouds might be plankton's way of moving a great distance.' "E: New collision models for asteroids suggest that chunks of rock might be flung from planet to planet, with live bacteria intact. Spores of 'Bacillus permians' have been known to survive for 250 million years. "F: Thomas Gold's deep hot biosphere theories. Yes, they are odd and his book makes a wide array of claims. But those claims don't all have to be factual, in order for there to be a lot – a whole lot – of primeval living biomass deep in the crust of the earth. Tectonic drift is a geological commonplace now, and that wasn't accepted until the 1960s. How much of what we think we know is wrong?"
Oliver Morton remarks:
You're right; it's an interesting constellation. Just to be clear, (D), the original long distance plankton transport idea isn't mine, but Tim Lenton' s and the late Bill Hamilton's. Refs are in the piece at:
Link:
I just did an article on (C), the Venus stuff, for
Science ("Don't Ignore the Planet Next Door" November 29;
298:1706-1707). The Venus clouds people and the earth
clouds people are beginning to talk to each other.
(B) is, in my view, looking shaky; but the general
idea of a refuge in the Martian depths (analogous to the
refuge in the Venusian clouds – the Mars bugs needed to
warm up when their surface froze and so dug down, while
the Venus bugs needed to cool off when their surface
boiled and so went up) is very much front and centre. (It
also predates the meteorite finding – more on this in my
book "Mapping Mars", in a chapter called "The
Underground".) At the moment, astrobiology is pretty much
entirely astromicrobiology.
(E) is becoming increasingly mainstream, to the
extent that questions about the presence and origin of
life on the terrestrial planets are being decoupled. Life
might have come about only once in this solar system – on
Mars, Venus, the Earth or even, conceivably, the Mars-
sized planet, sometimes called Orpheus or Thelia, that
smacked into the Earth to create the Moon – and still
have ended up on all of the others.
Mars is arguably the best candidate for the origin of life, because it may have been drier than the others. Hit a wet planet with a big rock and you boil the entire oceanic water complement, producing an atmosphere of live steam that lasts for thousands of years, and thus sends a sterilising heat pulse quite deep into the crust, which makes life difficult. Such boiled-ocean events may have frustrated early life on the Earth a number of times in the first few hundred million years. They may also have produced a selective advantage for bugs which can fly through space – in some such events the only survivable place to be would be on a rock heading outwards. Most such bugs would end up back on the planet they were launched from. Some wouldn't. Meteorite transfer makes the possibility of life on other planets at some time in their history greater, which is exciting if you want to find signs of life elsewhere, but also makes the possibility of that life having come about through a separate origin event from our own smaller, which is frustrating if you want to understand life in general. Swings and roundabouts. (I've been trying to get people to refer to this one-to-one exchange of spit between neighbours as "transpermia", to differentiate it from broadcast one-to-many panspermia, but so far to little avail.) On earthly cloud news, the University of East London project to start doing RNA analysis of bugs in Earth clouds looks likely to get underway next year. On the Gold stuff, a few points. One is that there are two different propositions: a deep biosphere, and a deep biosphere that produces hydrocarbons from primordial methane. Many will buy into the first, pretty much only Thomas Gold and his Russian colleagues into the second (primordial methane requires that the mantle be chemically reduced, whereas a lot of other evidence suggests that it's largely oxidised). Critics point out that, for Gold, the deep biosphere is essentially an epicycle added to explain the clearly biogenic markers in oil; these were a problem for the original version of the deep abiogenic hydrocarbons theory. Another is that the biomass of a system is not necessarily an indicator of its importance in the global cycles. Terrestrial biomass is hundreds of times that of the oceans, but the oceans are pretty close to equal in terms of such things as carbon sinkage. If there's a lot of biomass underground, that doesn't mean it's doing much. In nutrient-poor systems the doubling time for bacteria can become incredibly slow – decades, maybe centuries, maybe more. When biomass is taken as equivalent to the "amount of life" there's a risk of mistaking the size of the fireplace for the heat of the flame. Another is that your point that "Tectonic drift is a geological commonplace now, and that wasn't accepted until the 1960s" has a certain irony, in that Gold doesn't accept plate tectonics. Gold makes much of reports of some oil fields apparently refilling themselves from beneath, but he has to face the fact that in general US oil production has followed pretty much exactly the curve that Hubbert predicted it would without refilling. I find it hard to believe that oil geologists (who, in my experience really want to find more oil* – it's built into their psyches and their career incentives far more than a need to be intellectually modish is) would want to or be able to ignore this or hush it up. But then institutions do do strange things to the way people think. I wish there was a better dialogue between Gold and
the geologists; there are strange things going on down
there, whether or not they produce the hydrocarbons. But I
fear there won't be. Gold really does seem to think
geologists are all dunces, and geological lore is full of
stories about physicists telling them what could or could
not be possible and then ending up wrong. Lord Kelvin on
the age of the earth was wrong, most notably, but there
were also physical arguments against continental drift,
which many field geologists, expecially paleontologists,
were inclined to accept. There's a very good book about
this by Naomi Oreskes called "The Rejection of Continental
Drift". This means geologists see interventions like
Gold's as arrogant and ignorant, and may be tempted to
dismiss them without sufficient thought.
(Ignore silly subbing error as to his age – Professor Gold is in his 80s, not 90s) best and seasonals o Oliver Morton abq72*dial.pipex.com Available through amazon.co.uk and amazon.com "The equivalent in scientific reportage of the Nigella Lawson approach to cookery" -- The Sunday Times (no, I don't know what that means, either...) O=c=O O=c=O O=c=O O=c=O O=c=O O=c=O O=c=O |
