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Unforced Variations: May 2013

Filed under: — group @ 3 May 2013

This month’s open thread.


551 Responses to “Unforced Variations: May 2013”

  1. 101
    SecularAnimist says:

    Thomas Lee Elifritz wrote: “The fact that DNA exists in this universe is demonstration enough that it can self assemble …”

    That depends on how you define “self” … doesn’t it?

  2. 102
    R. Gates says:

    Some of you dicussing the evolution of life, may find this article and research interesting- Did the Universe evolve simply to create black holes?

    http://phys.org/news/2013-05-universe-evolve-black-holes.html

  3. 103
    chris says:

    re @96 Oh dear, that’s entirely wrong Thomas. DNA doesn’t “self-assemble”. That’s obvious and beyond any dispute whatsoever. In all organisms that we know of DNA is synthesised via a complex series of enzyme catalysed reactions. The deoxyribonucleotides themselves are synthesised by their own set of enzyme-catalyzed reactions. DNA replication requires template strands, DNA polymerases, gyrase, DNA helicases, DNA ligase and so on. Every single organisms we care to look at has a similar biomolecular machinery, somewhat simpler in prokaryotes, somewhat more complex in eukaryotes. Your insistence that this doesn’t happen and that DNA simply “self-assembles” is just silly.

    Obviously this complex situation didn’t magic itself into being. These incredibly complex systems presumably evolved (in my opinion, most likely during the several 100′s of millions of years in the existence of the early earth). How did we get from simple chemicals in salty hot springs to the level of complexity we see in extant simple organisms and, those we presume existed several billion years ago? We don’t know. You seem to think you do know but are reluctant to tell us.

    Your idea that a straightforward and uncontroversial account of what is widely recognized to be a major gap in our understanding of life’s origins constitutes “invoking divine intervention” is astonishing!

  4. 104
    James Cross says:

    Chris, Thomas, Ray et al

    One last comment and I will let you get back to climate science.

    My blog is called Broad Speculations (BS :))for a reason. It does not pretend to be science but I do try to extrapolate and interpolate from science. I don’t mind things that aren’t well-proven scientifically as long as they are not unproven.

    If you actually read my post on Sharov and Gordon and my replies, you will see I disagree with it on a number of points. I found it interesting, however, and not silly. First, it raises the question about whether the complexity of the most complex organism at any point in time generally increases over time and whether there might be rule of thumb (like Moore’s Law) to measure it. Secondly, it brought to attention for me the problem of explaining the origin of life on Earth. The first organisms that we have evidence of appear relatively quickly in Earth’s history yet are already very complex. There doesn’t seem to be enough time for evolution to play a a major role in the development of the first organisms. So either the first organisms came from somewhere else or something other (and I am not implying supernatural )than evolution was at work.

    For those interested more in origins, you might also check out:

    http://broadspeculations.com/2012/12/22/the-algorithmic-origins-of-life/

  5. 105

    Why aren’t the amazing space probes here?

    Who says they aren’t? You?

    There are two bottom up approaches to this problem that I can think of off hand, one I already mentioned, you seed using directed panspermia and the when you finally do arrive, you clone the local inhabitants and set them up locally in isolation to observe, and where or whenever appropriate, intervene. Alternatively, if you are interested in what is going on in an alternative universe, you tunnel in somehow and literally create the eyes on the ground the hard way, by evolution. That gives you the big picture.

    More on topic though, carbocide wouldn’t necessarily be bad for the biosphere of a planet like Earth, were it not for the anticipated hungry and nutty seven to nine billion semi-intelligent paranoid half apes here.

  6. 106

    Oh, oh, this result (if it holds up) can’t be good news:

    http://www.sciencedaily.com/releases/2013/05/130505145935.htm

    “New Berkeley Lab research offers a way to envision a warmer future… The approach foresees big changes for one of the planet’s great carbon sponges. Boreal forests will likely shift north at a steady clip this century. Along the way, the vegetation will relinquish more trapped carbon than most current climate models predict.”

  7. 107
    Jim Galasyb says:

    #105 Thomas observes: Carbocide wouldn’t necessarily be bad for the biosphere of a planet like Earth, were it not for the anticipated hungry and nutty seven to nine billion semi-intelligent paranoid half apes here.

    “The future is bright for dinoflagellates.” — Jeremy Jackson

  8. 108

    The first organisms that we have evidence of appear relatively quickly in Earth’s history yet are already very complex. There doesn’t seem to be enough time for evolution to play a a major role in the development of the first organisms.

    I don’t think you are adopting a broad enough definition of ‘evolution’ as it pertains to all things physical and chemical. If you accept that most of this was built in before it was ever mixed up in the soup of primordial earth then it shouldn’t take long at all since a variety of energy gradients are in place and the stellar burning and nucleosynthesis have already done most of the work. For instance, electron by themselves aren’t all that interesting and are relatively simple and straightforward, but electrons and atoms give us … life. Two hundred million years is a very long time from the perspective of electrons and atoms in aqueous solution.

  9. 109

    How did we get from simple chemicals in salty hot springs to the level of complexity we see in extant simple organisms and, those we presume existed several billion years ago? We don’t know.

    I’m almost positive it involves the collision and reaction of ions, atoms and molecules in aqueous solution under a gravitational gradient driven by a large variety of readily available long term energy conversion pathways. These particles themselves have a long and rich history before they even get into this long term energy rich aqueous chemical reaction environment with an active air sea land fresh water ice interface and an active cloud and hydrogeological cycle typical of a rotating terrestrial planet in the habatible zone of its common yellow parent star. This is an area I believe we are making great advances in, and is something I happen to know a little bit about. It would be great if you could discuss it at the level befitting the topic of ‘the origin and evolution of life’, as apparently we have reached a point called the present where our understanding indicates some changes need to be made.

    I don’t exactly know what you are trying to say, but ordinary chemistry appears to be quite sufficient to generate living organisms under the conditions we believed have occurred here in this particular universe. Unless you think chemistry itself has some kind of ‘ulterior motive’ in this whole affair. I myself would go with something much much earlier if I were to invoke cosmological conspiracy theories.

  10. 110
    David B. Benson says:

    Since some errors in the timeline appeared in earlier comments, one might care to review
    http://en.wikipedia.org/wiki/Archean
    or more briefly
    http://en.wikipedia.org/wiki/Timeline_of_evolutionary_history_of_life#Archean_Eon

    As I understand it, the evidence for the oldest fossils, at 3.8 bya, has been called into doubt as possibly solely chemical in origin. The later stromatolites are unquestioned.

  11. 111
    EFS_Junior says:

    JCH @ #8 said;

    http://www.realclimate.org/index.php/archives/2013/05/unforced-variations-may-2013/comment-page-1/#comment-336664
    __________________________________________________________________________
    The anthropogenic component of atmospheric CO2 has been doubling in around 30 years. If that rate continues, which is a function of human behavior, we will hit 520 around 2043.

    400 – 280 = 120
    120 x 2 = 240
    240 + 280 = 520

    According to ExxonMobil, growing world demand can be met through 2040, at which time they report that only 1/2 of the world’s liquid fuels will have been burned. If energy companies can meet growing world demand, the 30-year doubling period shrinks.
    __________________________________________________________________________

    Where do your “made up” numbers come from? Links please?

    We will NOT hit 520 ppmv of atmospheric CO2 by the year 2043 (or even sooner as you state with your closing word).

    Not going to happen, not even close to that number.

    Show me some kind, heck any kind, of reasoned scientifically based growth path that gets us to, or above, 520 ppmv atmospheric CO2 by 2043 (or sooner). Seriously.

    Not under any scenario by anyone who even pretends to have a hint of a clue on population growth, per capita fossil fuel growth, total fossil fuel emissions or the global carbon budget.

    We are currently at a rate of growth of ~2 ppmv/yr of atmospheric CO2, so to add 120 ppmv in just 30 years (or 4 ppmv/yr on average over the next 30 years), suggests for even a linearly increasing model (and if you use any non-linearly increasing growth model the end year growth rate would have to be higher) and end year growth rate of 6 ppmv/yr.

    So here’s a suggestion JCH, read the literature, look at the historic CO2 data, look at historic fossil fuel emissions growth, look at projected population growth and the energy growth estimates from the likes of the IEA, EIA, BP, Shell, ExxonMobile and BGR (which all go out to 2030 or 2035 or 2040).

    As to the recent literature see (for instance);

    http://www.nature.com/nature/journal/v488/n7409/full/nature11299.html

    http://people.fas.harvard.edu/~eebutler//Homepage/Plants_and_Climate_files/Ballantyne%202012%20Nature.pdf

    And if anyone tells you that they know all the components of the global carbon budget, with certainty and over time (past/present/future), to two or three or four or five significant digits, then you should know that that someone is outright lying.

    Here’s a clue, we all know less than we think we know. Some more so than others.

  12. 112

    By two hundred million years I mean after gas giant migration driven heavy bombardment ceased. Roughly, give or take. A hundred million here, ten million there. The bombardment distribution probably had a tail as well, and very likely contributed to the final result from what I’m reading lately.

  13. 113
    JCH says:

    Here we show that the anthropogenic component (atmospheric value reduced by the pre-industrial value of 280 ppm) of atmospheric carbon dioxide has been increasing exponentially with a doubling time of about 30 years since the beginning of the industrial revolution (∼1800)

    400 – 280 = 120
    120/2 = 60
    280 + 60 = 340

    ACO2 was 340 in 1981.

    2013 – 1981 = 32 years. 60 ppm, the anthropogenic component, doubled.

    For “business as usual” global CO2 would be expected to double (2 x pre-industrial levels or 560 ppm) in about the year 2050. – David Hofmann

    NOAA Earth System Research Laboratory, 325 Broadway, Boulder, Colorado, 80305
    CIRES, University of Colorado, Boulder, Colorado, 80309

  14. 114
    Pete Dunkelberg says:

    Proof that the space probe speculation is getting out of hand: Thomas writes

    > nutty seven to nine billion semi-intelligent paranoid half apes here

    Half apes? We are 100% ape unless there has been some hybridization I don’t know about. ;)

  15. 115
    Paraquat says:

    I have a question that I hope someone knowledgeable about climate and meteorology can answer for me.

    The UK, Ireland and nearby areas in northwest Europe have been experiencing pretty cold winters over the past couple of years. Colder in normal there, from what I understand. This, of course, is being touted by the UK denialist crowd that global warming is a myth. Now let me be clear that not among those denialists. I fully appreciate that it can be colder in one place while the rest of the world is experiencing above-normal temperatures. I’m just trying to get a handle on what is causing the unusually cold weather in the UK. Looking to google for answers, I see references to the jet stream having moved further south, and talk (but nothing scientific) about the Gulf Stream also being further south. I don’t know if either is true, or why it would be happening. I’m also curious to know if this is expected to be a long-term trend due to climate change, or merely a temporary condition (that is to say, simply “weather” not climate).

    I am aware of what is called the North Atlantic Oscillation, and that could provide an explanation, but not sure if that is what we’re seeing here, or if it is another phenomena.

    I hope that someone who actually has good knowledge (and not mere speculation) can shed some light on this.

    Thank you in advance,
    Paraquat

  16. 116
    Eric Rowland says:

    Revisiting the “Why do we care what the idiots think” meme, we care because there are a wide range of possible outcomes from this point and keeping the “idiots” and their mentors in check is important. I read the latest incarnation of J Curry’s reckless, fake hand wringing this weekend.
    * There is deep uncertainty. The phenomena are only poorly understood.
    * We must delay to reduce uncertainty
    * We must invoke the precautionary principle
    * It’s difficult to untangle the roles of AGM vs. natural variability

    Just a sample of 15 pages of nonsense. The “idiots” are busy digesting and redeploying all of it. If we don’t care, they win.

    http://curryja.files.wordpress.com/2013/04/curry-testimony-2013-il.pdf

  17. 117
    Pete Dunkelberg says:

    Comment/question on David Benson @ 110

    > …the evidence for the oldest fossils, at 3.8 bya, has been called into doubt as possibly solely chemical in origin.

    so far so good. Then:

    > The later stromatolites [presumably from 3.5 Bya] are unquestioned.

    OK, but complex ecosystems don’t pop up over night like mushrooms. When do you suppose life started on earth?

  18. 118
    Chris Korda says:

    Why aren’t the amazing space probes here?
    Who says they aren’t? You?

    It seems RealClimate’s open thread has been colonized. I’m disappointed, because it used to be a terrific climate science resource. With luck the flames will eventually be extinguished by moderation and/or a shortage of tinfoil. I’ll check back in a few months.

  19. 119
    Rafael Molina Navas, Madrid says:

    So called “Fermi Paradox”
    “At any practical pace of interstellar travel, the galaxy can be completely colonized in a few tens of millions of years” (by a civilization like ours, after much much longer development …)
    Does anybody actually think our civilization could carry on with our development model for millions of years?:
    http://www.bbc.co.uk/news/science-environment-22425219
    http://www.bbc.co.uk/news/science-environment-22408341

  20. 120

    Rasmus is engaging at ClimateDialogue in a discussion with Koutsoyiannis and Bunde about long term persistence (LTP) and its relevance for detection of global warming above and beyond what would be expected from internal variability.

    http://www.climatedialogue.org/long-term-persistence-and-trend-significance/

    All three invited participants agree that climate forcings can also contribute to LTP and that forcings are omnipresent in the data. It follows that the presence of LTP by itself does not indicate a dominance of internal variability, despite the (implicit or explicit) claim often made that it does.

    There’s also a (moderated) public discussion. Feel free to chime in.

  21. 121

    From JCH’s source paper (#113): “…anthropogenic atmospheric carbon dioxide and world population have followed a power law relation with an exponent of about 1.35. This is not expected to continue in the future as population is expected to peak at about 9 billion in about 2050 and carbon dioxide emissions are expected to stop increasing.”

    So, BAU gives us 560 ppm or thereabouts at population peak–except, of course, that we don’t really understand the Earth system carbon cycle feedbacks well enough to know what ‘natural’ (or should I say, ‘second-order anthropogenic’) carbon increases may be at that point. It’ll be pretty amazing if there’s much summer ice in the Arctic by then, and a lot of permafrost will be history, too. So one would expect a much heavier methane burden–and that keeps degrading to CO2. So maybe CO2 concentration growth rates will slow after 2050, but surely concentrations will not stabilize?

  22. 122
    Yvan Dutil says:

    Galactic colonization is rather tricky if you first need to survive on your own planet. This would require to shut down the growth, which reduce the need for a galactic colonization. This is a paper that I have written that demonstrated just that.

    http://arxiv.org/abs/0711.1777

  23. 123
  24. 124

    I’ll check back in a few months.

    Thin skin doesn’t work when cutting edge science reveals extremely dire astrophysical, geological and environmental problems that suddenly require our immediate close attention. I have no sympathy for you, sorry.

    If you feel that you can stomach participation in these extraordinary investigations that could possibly enlighten us to possible solutions, your help in these matters would be much appreciated, because the problems of biospheres, astrophysics, widespread surface chemistry, humans, pollutants, overpopulation and close mindedness aren’t just going to suddenly disappear without these kinds of engagements. If you want to just stay focused on your own little world then I guess that’s ok as well.

  25. 125

    Does anybody actually think our civilization could carry on with our development model for millions of years?

    Civilization could, easily. Solar irradiance and solar system resource exploration and exploitation models using reusable chemical (methane and hydrogen) launch vehicles have already been roughly sketched out at the engineering level. That should keep us busy, The question is can our civilization do it, given the damage we have already caused to the biosphere.

  26. 126
    Pete Dunkelberg says:

    Paraquat @ 115 That changes in the Arctic are bound to affect northern hemispheric weather, and are doing so is agreed in reality oriented circles. That ocean warming keeps right on going, even speeding up a bit, is the subject of the previous topic here at RC. 2012 was the warmest La Niña year yet, and warmer than any El Niño before the very big one in 1998. You can always check arguments at http://skepticalscience.com/

    But I think your best source right now may be
    http://data.giss.nasa.gov/gistemp/maps/
    You can make monthly maps, just for winter months if you like, or each individual month all year for a couple years. Rather than the alleged cold winters, you will find surprising regional changes from month to month. Going through the most recent Nov, Dec, Jan, Feb, March you will see a big change right about when the Arctic vortex split into two vortices, allowing more than the usual amount of polar air to spill out. Try it!

  27. 127
    SecularAnimist says:

    David B. Benson wrote: “As I understand it, the evidence for the oldest fossils, at 3.8 bya, has been called into doubt as possibly solely chemical in origin.”

    As I understand it, life is “solely chemical” … isn’t it?

  28. 128
    Rafael Molina Navas, Madrid says:

    #125
    “The question is can our civilization do it, given the damage we have already caused to the biosphere”
    Haven´t you seen that´s my point too? (#119) That´s why I included:
    http://www.bbc.co.uk/news/science-environment-22425219
    http://www.bbc.co.uk/news/science-environment-22408341
    What is happening in the Artic is a very grave sign of our irresponsability, to say the least.

  29. 129
    R. Gates says:

    Pete Dunkelberg said:

    “Going through the most recent Nov, Dec, Jan, Feb, March you will see a big change right about when the Arctic vortex split into two vortices, allowing more than the usual amount of polar air to spill out. Try it!”

    ___

    You are of course referring to the SSW event that took place early in January, altering the entire weather pattern of the NH. These events, especially when large like we had this year, tend to dominate the winter’s weather once they happen, and northern Europe’s weather really changed after that SSW split the vortex.

  30. 130
    Titus says:

    Pete Dunkelberg @98. You comment:

    “I’m not sure what you are thinking but you seem to be thinking”

    Haha – That makes two of us!! If you find out let me know:)

    I’m an average Joe when it comes to scientific matters with a pretty broad reach but not too deep level of knowledge. The input from contributors on this blog has been a great mix of views which have been intelligent and informative and challenge me. That’s been great and I give my thanks.

    My motivation in joining in part is to try and discover if science has diffinitive answer to the old old questions of the origin of life, consciousness etc. To be honest my thoughts right now are that we still are no wiser than the ancient philosophers. I thought the comment by ‘Chris’ who used the word ‘mystery’ is most apt.

    For those familiar with Hitch Hiker Guide and the super computer, Deep Thought, who processed the question of the mearning of life and everything. After millions of years it came up with the answer of 42. I’ll stick with that for now!!!

  31. 131
    Alan Harvey says:

    Rafael Molina Navas @119 A quick back of the envelop calculation assuming an economic growth rate of 1% per annum. This requires the economy (~consumption of materials and energy) to double every seventy years. Over 10 million years this would be ~140000 doublings or about 10^42000 times the size of the current economy.
    ‘ we’re gonna need a bigger universe !’

  32. 132
    Patrick says:

    @ 125 Hear, hear. But is anybody sketching a new aerosols satellite?
    Thank you very much.

  33. 133
    David B. Benson says:

    Pete Dunkelberg @117 — My understanding is that the stromatolites are dated at 3.4 bya but I won’t quibble over a mere 100 million years. :-)

    Presumably those fossils are the remains of proto-cyanobacteria (based solely on modern stromatolites); the modern ones are rather complex, but have experienced an additional 3.4 billion years of evolution. So all the evidence I know about indicates that abiogenesis occurred more than 3.4 bya. Without more knowledge than I have of
    http://www.ucmp.berkeley.edu/precambrian/archean_hadean.php
    eon conditions, I’ll not venture a guess.

  34. 134
    Chris Colose says:

    Moving the discussion of extraterrestrial life back into the realm of science:

    Kepler is already set to put several thousand objects into the exoplanet catalog after just a couple years of being in operation, so we know the availability of planets is not a problem. In fact, there’s planets almost everywhere being looked at within Kepler’s field of view, and the diversity (e.g, orbital period, eccentricities, albedos, planetary size ranges, etc) is incredible…far more than what one could intuit from the small sample size in our own solar system. The next step technologically will be to get spectra of Earth to Neptune sized bodies, something already being done for exoplanetary gas giants. Indications of biomarkers in these atmospheres (e.g., oxygen and ozone signatures) is going to be the way life gets discovered, if we are lucky enough for that to happen anytime soon.

    From a purely climate standpoint, there’s no reason Earth should be exceptionally unique regarding the ability to support life. We have an incredibly small sample size in our own solar system– only a few dozen objects (between planets and moons), and only a handful of rocky objects with a distinct surface. So the argument of lack-of-life elsewhere in our own solar system isn’t very compelling.

    What’s more, I’d argue that observers in other galaxies that were looking at our solar system would be able to reasonably infer that Earth was the best potentially habitable body in our solar system…based only on knowledge of orbital distance from our own Sun, and the conventional ideas that are already developed about how to support liquid water on a planet’s surface. In that sense, the lack of non-Earth life in our own solar system is expected rather than being evidence of uniqueness at the cosmological scale.

    The current models of orbital distances that are compatible with liquid water (which is a function of star type) are pretty wide. Earth is closer to the inner edge of that orbital range, Venus is empirically too close, and actually the outer limit probably extends beyond Mars. The problem with Mars is that it’s too small to have much atmosphere to compensate for the lack of solar heating, but that’s not an issue that should be general to all planets at a Mars-like orbit. If we can find good greenhouse gases that don’t condense easily, the outer edge gets extended even further (this has been thought about for H2, and even having larger atmospheric pressures of N2, etc would help).

    There’s a lot of other issues worth discussing, such a whether tide-locking is a big problem, etc. But right now there’s nothing going on in the exoplanet community that points toward Earth being some sort of 7-card Royal Flush in the universe…maybe a 4-of-a-kind, but that’s still good enough given the number of stars out there.

  35. 135
    EFS_Junior says:

    #113, JCH said;

    http://www.realclimate.org/index.php/archives/2013/05/unforced-variations-may-2013/comment-page-3/#comment-336859
    __________________________________________________________________________

    Links to some person’s paper (who has now gone to the great beyond, RIP) that “curve fits” an exponential to ~50 years of CO2 observational data using a baseline of 280 ppmv (which is valid for all time from the Big Bang to Infinity and Beyond or so JCH would appear to assume).
    __________________________________________________________________________

    Fitting an exponential has got to be the oldest curve fitting trick in the book. But it is not science, it is curve fitting, just as plain and simple as that.

    So, for example, that paper’s equation, gives for 2013, a rate of 2.5 ppmv/yr, but dog gone it, that damn observational CO2 global data is today, in 2013, still bouncing around at 2.0 ppmv/yr, NOT 2.5 ppmv/yr.

    I will go on record as stating that ACO2 in 2043 will be …

    477.5 ppmv (one sigma ~7.5 ppmv)

    I mean, we are, after all, talking about curve fitting, now aren’t we?

    So, 520 ppmv (at least that value in 2043) – 477.5 ppmv = 32.5 ppmv
    32.4 ppmv / 7.5 ppmv ~ 4.5 sigma

    Oh, and here’s a link for you, from a crank even (and it’s NOT behind a paywall, just like the last paper I provided), some, you know, food for thought;

    http://www.sciencedirect.com/science/article/pii/S1352231010001561
    http://88.167.97.19/albums/files/TMTisFree/Documents/Climate/The_estimation_of_historical_CO2_trajectories_is_indeterminate_Comment_on_A_new_look_at_atmospheric_carbon_dioxide_Loehle_2010_AE-1.pdf

    Who will be closer? See you all in 2043, same bat time, same bat channel.

  36. 136
    David B. Benson says:

    SecularAnimist @127 — I should have stated solely geochemical.

    Chris Colose @134 — I suggest taking Ward & Brownlee’s “Rare Earth” arguments more seriously than they do themselves. While there certainly have been some lucky events (lucky for the evolution of Homo sapiens) in Terra’s history, the luckiest of all appears to be abiogenesis. Until the conditions for the creation of life is better understood we can only speculate about planets in similar orbits around other stars.

  37. 137
    Martin Vermeer says:

    Chris Colose #134:

    So the argument of lack-of-life elsewhere in our own solar system isn’t very compelling.

    Actually Titius-Bode’s law already tells us not to expect more than one life-bearing planet per star. Otherwise, bodies of liquid water are found in two places (the other one being Europa, under the surface) and existed earlier in four (also Mars, and Venus apparently had a world ocean), complex carbon chemistry in two places (Titan)…

  38. 138
    David Goldstein says:

    Hey all: Here is my latest climate change article over at Huffington Post. Please give it a look! http://www.huffingtonpost.com/davidgoldstein/burn-baby-burn-a-climate-_b_3224411.html?utm_hp_ref=climate-change

  39. 139
    Patrick says:

    @128 Rafael Molinas Navas. After reading this in the article you cite:

    “Scientists at one time believed their shrinking numbers were caused by an infection, but they couldn’t find the underlying cause.”

    –let me cite this, especially the abstract:

    http://phys.org/news/2013-04-high-fructose-corn-syrup-tied-worldwide.html#jCp

    The fault is not in our stars but in ourselves, as we may see.

  40. 140
    chris says:

    James @104,

    Sharov and Gordon is silly because they use a non-scientific reductio ad absurdum argument (extrapolating molecular genetics in extant organisms back to a single nucleotide as an estimate of the time of life’s origin). Having presented that dull trick they engage in page after page of irrelevant (and rather nasty in my opinion) pub talk.

    Anyway the last two sentences of your post are very relevant to this fascinating problem:

    “There doesn’t seem to be enough time for evolution to play a a major role in the development of the first organisms.”

    Very interesting comment since it suggests we might have some idea or gut-feeling about how long the development of the first living organism should take. I don’t think we do. A million years is a mind-boggling period of time and who’s to say that the development of the first simplest self-replicating simplest organism didn’t take 100 million years or less. What basis do we have for assuming otherwise? After all Stanley Miller who stimulated much of the field of modern abiogenesis considered that the evolution of the first cyanobacteria might have taken 20 million years. [1]

    “So either the first organisms came from somewhere else or something other (and I am not implying supernatural )than evolution was at work.”

    Yes something other than evolution was at work. It’s called chemistry. A major fallacy of Sharov and Gordon is not to recognize that in extrapolating extant molecular genetics back in time, we expect to meet the slope of chemistry going forward. The slope of the chemistry time line from prebiotic soup (!) to first self-replicator might be quite steep indeed as Miller suggested. But since we don’t know what chemistry was involved we are largely guessing. I’m more than comfortable with our lack of knowledge of life’s origins.

    Incidentally Leslie Orgel (like Stanley Miller no slouch on the science of life’s origins) put it rather well [2]:

    “We do not understand how a self replicating system originated on the primitive earth, so it is impossible, on the basis of chemical arguments, to set upper or lower limits on the time that would be required. Hopefully, further research will clarify the nature of the chemical steps involved. Then we might be able to offer some meaningful estimates about the time needed for the transition from an abiotic to a biotic world.”

    [1] A. Lazcano and S. L. Miller. How Long Did It Take for Life to Begin and Evolve to Cyanobacteria? J. Mol. Evol. 39, 546-554 (1994).

    [2] L.E. Orgel. The origin of life: How long did it take? Origins of Life and Evolution of the Biosphere 28: 91–96, 1998

  41. 141
    Salamano says:

    @ #134.

    I’ve found it somewhat humorous that there are people out there that are labeling our future climate as unlivable, or the oft-used “as we know it” being applied to the end of working human civilization…

    …and yet the range for ‘acceptable habitation’ of a Kepler discovered planet is MUCH more forgiving. Even what our future climate has for us via GCMs would be labeled as within the ‘sweet spot’ for a newly discovered distant planet.

  42. 142
    Simon C says:

    Doesn’t the foolishness of releasing self-replicating artificial organisms (“probes”) into the galaxy occur to anyone? Before long they would be competing for resources, developing increasingly lethal defense and attack systems, and be about as interested in the fate of organisms – such as those that produced them – as we would be in slime molds. Unleashing them would be about as daft as a species playing dangerous games with the composition of the atmosphere of its own planet. Hmmm, hang on a minute …

  43. 143
    john mann says:

    General question: one of the debates in climate is the role of DMS in cloud formation. Has any work been done on possible biologic sulphur fractionation and its use in differentiating SO4 production from volcanic sulphur?

    Caveat: it’s come out of OU study, but it’s not in response to any assignment or exam.

  44. 144
    Rafael Molina Navas, Madrid says:

    #131 Alan Harvey: Millions of years of “development” is part of the Fermy paradox hypothesis …
    I wouldnt´ dare to extrapolate curren “growth” …
    I just wanted to express what shown in #128 … Absurd paradox? If our minds also developed … who knows? But in spite of the unbelievable technology development, our minds haven´t improved in millenia …

  45. 145

    #141–”Even what our future climate has for us via GCMs would be labeled as within the ‘sweet spot’ for a newly discovered distant planet.”

    Sure. But I’m rather attached to the civilization and culture into which I was born, so the probability that humans will survive the worst that we can do to our own nest does little to console (much less ‘amuse.’) Mozart deserves to remain ‘immortal’, which would be difficult, to say the least, under 8 C warming by 2100.

  46. 146
    jgnfld says:

    @141
    Personally, I find it equally if not more humorous that you cannot see the difference between building up the resources of a civilization over time starting from scratch (centuries in our own case) in a way adapted to a stable environment on whatever planet versus having to scrap a large portion of the centuries-old investment and start over anew from scratch due to a changed environment.

    You’ll be giggling in your grave over the taxes necessary to accomplish this, but I doubt any of your putative children will be.

  47. 147
    Martin Vermeer says:

    Salamano #134, you cannot quite compare the scope of life’s adaptation over a stellar lifetime with that of humanity’s adaptation over a century. “Orders of magnitude difference” doesn’t begin to capture it. Planets don’t have to appear hospitable to us to be perfectly comfortable to the natives.

  48. 148
    Ray Ladbury says:

    Salamano,
    I’m sure that whatever evolves to take our place will share a giggle with you.

    Meanwhile we’ll just laugh at you silliness.

    You fail at physics. You fail at biology. You fail at astrobiology. You fail at logic. You fail at reading comprehension. Get the drift?

  49. 149
    SecularAnimist says:

    Chris Colose wrote: “… the argument of lack-of-life elsewhere in our own solar system isn’t very compelling”.

    Especially given that there may very well be life elsewhere in our own solar system.

    Chris Colose wrote: “… the conventional ideas that are already developed about how to support liquid water on a planet’s surface …”

    There are, of course, other places where liquid water can exist besides a planet’s surface.

  50. 150
    simon abingdon says:

    The number of stars in the universe has been estimated on the low side of 10^24 which approximates to 2^80. If our own example of intelligent life has had to survive more than 80 potentially negative bifurcations in its Earthly evolution since abiogenesis over maybe 4 billion years ago (that’s an average of just 1 every 50 million years) then it’s unlikely there can be anything comparable elsewhere in the universe, regardless of the availability of suitable planets.


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