I woke up to a very interesting paper by Gibson, Wickramasinghe, and Schild that appeared on the ArXiv last night and suggests that life most likely developed shortly after the big bang and was then spread throughout the universe. They call this the biological big bang. (And at this point I should say that universe here means the "local universe" that was in casual contact between 2-8 million years after the big bang.)I will show some plots and quotes below, but before I do I want to give the main arguments of the paper:
1. Complex life originating on this earth is very improbable and scientists who believe such a thing are dismissing how unlikely it is.
2. However after the big bang there was a brief period, between 2 and 8 million years after the big bang, where the formation of life becomes highly probable for these reasons:
- The entire universe (not just one planet) was the in the critical temperature range (273-647K) for the formation of water and complex organic molecules like RNA.
- The first supernovas had already by this point ejected the necessary elements and chemical compounds needed for the formation of complex organic molecules.
- The elevated pressure and density of the universe at this stage contributed to very high reaction rates such that extremely unlikely molecules form quickly.
- The elevated pressure and density of the universe at this stage further kept the majority of the universes in constant communication such that a survival of the fittest scenario could play out.
4. Life did not originate on earth but came to this sterile earth from another sector of the universe through these comets and meteors.
5. The fundamental building blocks of life might actually be the same throughout the whole universe. (With the reminder that here I mean the local section in causal contact between 2-8 millions years after the big bang.)
6. There is evidence for extra-tereestrial life.
Now, I'm not a bio-physicist so experts can correct me if any of the above is inaccurate, but I'm pretty sure those are the main ideas and conclusions discussed in the paper.
Quotes and plots for more details:
Gibson et al. starts out with the following questions:
Why should Earth be the only planet with life? Astrophysical spectra show dust clouds dominated by polycyclic- aromatic-hydrocarbons (PAH), strongly indicating that biological processes are commonplace in the Galaxy. The theory of cometary panspermia provides the logical mechanism for distribution of the seeds of life, but how are sufficient numbers of comets and meteors formed? How, when, and where did life begin in the first place, how widely is it distributed, and are life forms likely to be similar everywhere?
To which they respond:
In the present paper we explore aspects of this HGD (hydro-gravitational-dynamics) model in greater detail, suggesting that the conditions within ultra-high pressure interiors of primordial planets at 647K provide optimal conditions for life’s first origin. Given the large cosmological volumes available and the numerous panspermial mechanisms for communication of life templates provided by HGD cosmology, first life most plausibly appeared and was scattered among 10^80 available planetary interiors produced by the big bang in the time period t = 2-8 Myr. We term this period the biological big bang.And here are some plots:
In this above plot they show their timeline of the early universe. Life begins at the "Goldilocks" temperatures and conditions and the necessary DNA/RNA molecules are carried away by comets.
This image is given as evidence for extra terrestrial life like ours. It is an image of "Cyanobacteria fossils observed by Richard Hoover in Orgueil and Murchison meteorites." In their paper they give evidence that the Red Rain organism is extra-terrestrial.
One more choice quote:
First life is assumed to have occurred on Earth since we see life everywhere and are taught to believe no convincing evidence exists for extraterrestrial life. Copernicus convinced the scientific community, and finally even the Vatican, that the Earth is not the center of the universe, and has recently been buried in hallowed ground. However, with respect to living organisms the scientific community remains in a pre-Copernican position, fiercely resisting concepts that DNA and many diseases and possibly antigens on Earth are continuously supplied by extraterrestrial sources. Because life exists profusely on Earth it is assumed that the formation of life must be a rather trivial matter, and that possibly life began spontaneously on this planet in several ways since life has existed from its beginning 4.6 Gyr ago. However, all laboratory attempts to create life have consis- tently failed and all serious attempts to model probabilities suggest they will always fail. Life chemistry is too complex to replicate with present technologies on human-life-time scales.
The standard Earth-based models for the origin of life, inspired by early suggestions of Haldane (1929) and Oparin (1957), are all based upon an unprovable article of faith. Faith comes in by pos- iting the existence of complex chemical pathways that are yet to be discovered, reaction networks that are somehow capable of bridging the difficult gap between chemistry and biology... Fred Hoyle in his classic book and lectures “Frontiers of Astronomy”, Maddox (2003), proposed the entire solar system as a better venue than Earth for the origin of life.So again, if the paper is correct, it appears that life may have originated shortly after the big bang in a "biological big bang" and was then distributed throughout an otherwise sterile universe on planets like our own earth.
Carl H. Gibson, N. Chandra Wickramasinghe, & Rudolph E. Schild (2010). First life in primordial-planet oceans: the biological big bang Submitted to International Journal of Astrobiology. arXiv: 1009.1760v1
A very interesting paper indeed! Reading Joseph F. Smith gives the impression that Adam was transported to Earth from another place. I guess a microbe dormant within a comet for 10 billion years and smashing into Earth to get life started works just as well.
ReplyDeleteStan,
ReplyDeleteWell, we are convinced comets brought us water so maybe they brought us the building blocks of life as well. :)
I'm not sure why we have to consider all of these ideas as a 'package'.
ReplyDelete1) The idea that life has (also) originated elsewhere in the universe
2) That life can traverse space
3) That abiogenesis is vanishingly improbable.
It's perfectly reasonable to think that 1 or 2 could be true. It's also fine to consider that IF 3 is true, then it does lend some support to 1 & 2. However, 1 & 2 are still interesting even without 3 being true.
I do note that Wickramsinghe's probabilistic treatment of abiogenesis has a section of the talk/origins FAQ dedicated to it, and it certainly isn't considered the last word on the matter, or the only serious attempt at modeling...
http://www.talkorigins.org/faqs/abioprob/abioprob.html#Intro
sorry, couldn't make the html work...
tbell,
ReplyDeleteThank you for your comment. I was not aware of that above link so thank you for posting and admit I am not an expert regarding Abiogenesis.
But I am sure you are right that all these ideas are not necessarily part of the same "package".
Perhaps I'm missing something here, but 2-8 Myrs after the big bang was around redshifts 200-150. There were no stars around then to create the heavy elements needed for DNA (notably carbon). And, if I remember right, the lifetime of a 30 solar mass star is just barely 2 Myr. So, if we wanted metals from it, we'd need the star to form right at the Big Bang, which isn't happening.
ReplyDeleteHowever, I was shocked when I calculated the MilkyWay crossing time for a meteor moving at 100 km/s -- roughly 120Myrs. There would be plenty of time, then for life to have been formed elsewhere (or multiple elsewheres) in our Galaxy, and then spread across. But, there would have to be a lot of meteors -- the cross section of a meteor aiming for our solar system is pretty darn small. So small, that when the Milky Way and Andromeda galaxy collide in a few Gyrs, there will probably be only 1-5 actual stellar collisions.
So, good idea, but still many rough edges to work out.
So, wow. To analyze this takes some major comment.
ReplyDeleteFirst, let me get the context of my comment down. I'm currently taking a course in astrobiology, I don't think Wickramasinghe's pathway for abiogenesis (first biological population from biochemical populations) is mentioned, it is too oddball and there are very many likely ones. Of course you shouldn't take my word as gospel, for one I don't have the books handy as I write this, but as caution.
Second, let me get the context of Wickramasinghe's abiogenesis research down, as it explains the paper's claims and my treatment of it. He was partnered with Hoyle, which on all accounts became crackpot on his steady state theory in later years (refused falsification) and was creationist.
Hoyle's is the "fame to shame" junkyard creation calculation of "probability of life" which is totally inapplicable to considered pathways (abiogenesis and evolutionary processes), and today can be seen referred to as "Hoyle's Fallacy" - tbell has astutely given an excellent reference to that mess.
Wickramasinghe (and here Gibson) follows in Hoyle's footsteps with theories that glues to any positive observation and, seemingly, refuse to consider negative (falsifying) ones. This is presumably why the paper consists of a Gish gallop of falsified or outright false claims. If this would be taken to the extreme, it would be a sign of pathological science.
Having said that, I will still comment on the paper as a whole before I single out some particular problematic claims out of the plethora which meaningfully no one could answer all.
The paper is a rehash of an earlier arxiv paper. It's terminology of biological "big bang" has already been used by biology luminaries like Koonin for other purposes. To Wickramasinghe's credit he doesn't misunderstand physicist use of big bang and environmental selection however, but points out that it isn't the a priori probability of the pathway that matters but the (accumulated) a posteriori likelihood.
On to the problematic claims. This is already a long comment so I will have to be briefer than I like.
ReplyDeleteFirst, HGD cosmology, which needs to be proven. For example, the "axis of evil" went away with better sampling (later WMAP data), why is it still in the paper and why didn't it oust the cosmology? (See pathological science above.)
Second, the HGD model used for abiogenesis rely on high metallicity already after ~ 1 My. But the surviving pop II stars which followed after the first non-metal stars still have low metallicity.
Third, transpermia, which needs to be proven. For example, interplanetary dust grains, cometary samples and asteroid samples - all loaded with organics, none showing trace life (for example, signs of metabolism).
Fourth, "extra-terrestrial life".
It is of course laughable when a picture is used to identify "cyanobacterial filaments". No self-respecting biologist would claim that from scant data. Hoover, which is again was associated with Hoyle, tries his damnedest to impute extra-terrestrial origins despite much of what he finds is the expected contamination. But extra-ordinary claims need extra-ordinary evidence.
That goes for "red rain" too of course. If they can grow the organism, why can't they sequence the DNA and make sure? The paper and the original papers won't tell. (See pathological science again. Now this seems like a theme...)
Finally, the real elephant in the room, the presumed problems for other pathways. Gibson et al mischaracterizes current research in their attempt to come up with a problem.
What is known is that there existed many likely local pathways, which were attempted simultaneously in competition and sometimes constructively and sometimes destructively interfered.
It isn't that life is profuse today which indicates abiogenesis was easy, but the speed with which it came to be. Trace fossils (photosynthesis) and fossils (photosynthetical bacterial mats) are found in the oldest surviving rocks already < 1 Gy after Earth formation.
Famous biologists like Miller calculates the time to first life < 13 My (because that is the mean time for free floating cells to start divide before the water they inhabit is recirculated into sterilizing heatvents). That is still too much time and too much volume to cover fully in lab experiments. Yet Gibson et al claims this is a problem for abiogenesis pathways - which is yet another false creationist argument!
[As a side note while it isn't relevant, it is interesting to see the dedicated synthetic pathway of Seth Shostak et al. They claim on sound and tested ground that a two-component system is enough to make the first cells, and they think they are mere years from making the first lab demonstration.]
To sum up then, a terrible paper, made out of thin space and wishes. While at the same time with too many attempts of creationist thinking and pathological science to be really funny.
"we are convinced comets brought us water"
ReplyDeleteSurely it is the other way around? It is the D/H isotope ratio (among others) that tells us that comets have contributed at most 10 % of the water, likely less. (What I remember from my 2006 astrobiology text book.)
In fact, there has been some recent progress to predict Earth's neodymium isotope ratio that shored up the evidence that the Earth-Moon system is mainly chondrite in origin.
[And found a predicted early mantle material reservoir as Baffin Island rocks, brought up by the hotspot that now sits under Iceland. Rocks from Earth, original material from likely within 30 My from formation! Um, that rocks...? :-D]
Still, that the bulk of common volatiles come from elsewhere doesn't hinder that the bulk of organics, or even essential ones, came from comets. That is also how our astrobiology course handled it, btw.
AndrewJDavis and Torbjörn Larsson,
ReplyDeleteThank you both very much for your analysis, since, as I admitted I am not an expert but nevertheless found the paper interesting so I am very much in debt to those like you who can elaborate on the more technical details.
AndrewJDavis,
Yeah, redshifts of 150-200 do seem outrageous so I do not understand what is going on there. Second, thank you for working out the MilkyWay crossing time as that is very interesting,
Torbjörn Larsson,
Thank you for taking the time to really dissect the paper and elaborating on the astrobiology details. Bye the way, as someone working on cosmology I can understand that if Hoyle is involved the ideas probably run against the mainstream. :)
Again, thank you both very much.
Well, perhaps life began from abiotic hydrocarbons or in hydrothermal vents.
ReplyDeleteMaybe that Red Rain originated in a volcano?
ReplyDelete