We all know that astronomy is just plain awesome – and pretty much everything that’s interesting in the world links back to astronomy and space science in one way or another. Here I’m thinking gravity, wireless internet and of course ear thermometers. But wouldn’t it be great if we could ascribe the whole origin of life to astronomy as well? Well, apparently we can – and it’s all about cosmic rays.
Three key contenders for how it all started are:
1) Deep ocean vents, with heat, water and lots of chemistry churning away, enabled the random creation of a self-replicating crystalline compound – which, being self-replicating, rapidly came to dominate an environment of limited raw materials. From there, because it was imperfectly self-replicating, particular forms that were slightly more efficient at utilizing those limited resources came to dominate over other forms and yada, yada;
2) Something arrived on a comet or asteroid. This is the panspermia hypothesis, which just pushes the problem one step back, since life still had to start somewhere else. A bit like the whole God hypothesis really. Nonetheless, it’s a valid option; and
3) The Miller-Urey experiment demonstrated that if you zap a simple mix of water, methane, ammonia and hydrogen with an electric spark, roughly equivalent to a lightning bolt in the early Earth’s prebiotic atmosphere, you convert about 15% of the carbon present in that inorganic atmosphere into organic compounds, notably 22 amino acid types. From this base, it’s assumed that a self-replicating molecule came to be and from there… well, see point 1).
Additional support for the Miller-Urey option comes from the analysis of ‘old’ genes, being genes which are common to a wide diversity of different species and are hence likely to have been passed down from a common early ancestor. It’s found that these old genes preferentially code for amino acids that can be produced in the Miller-Urey experiment, being the only amino acids that would have been available to early Earth organisms. Only later did a much larger set of amino acids become available when subsequent generations of organisms began to learn how to synthesize them.
Nonetheless, Elykin and Wolfendale argue that the available spark energy generated in a average lightning storm would not have been sufficient to generate the reactions of the Miller-Urey experiment and that an extra factor is needed to somehow intensify the lightning in early Earth’s atmosphere. This is where cosmic rays come in.
While many cosmic rays are generated by solar activity and most don’t penetrate far into the atmosphere, high energy cosmic ray particles, which generally originate from outside the solar system, can create electron air showers. These arise from a cosmic ray particle colliding with an atmospheric particle producing a cascade of charged pions, which decay into muons and then electrons – resulting in a dense collection of electrons showering down to two kilometers or less above the Earth’s surface.
Such a dense electron air shower could initiate, enhance and sustain a high energy lightning storm and the researchers propose that, perhaps when the early solar system was drifting past some primeval supernova event over four billion years ago, this was what started it all.
Awesome.
Now that’s looking at EU from the ‘far side’?
I am fascinated by ongoing elemental and chemo synthesis generated by high energy particle/waves upon the Earth and elsewhere. A hot topic! Recent discussions about the effects of those charged particles/waves on the moon come to mind.
Discussions concerning these E/M tornadoes (the shape of) as fractal progenitors of Martian Dust Devils and even Terran tornadoes welcome?
There we go again someone mentions electron and charge and the nuts come out.
This article has nothing to do with EU whatsoever.
It is a cosmic ray hitting the atmosphere collide and the explosion created particles including electrons. That is all, nothing exotic.
Just a burst of cosmic rays because some star exploded nearby and temporarily flooded the Earth..
Please see
http://www.nature.com/nature/journal/v465/n7295/edsumm/e100513-10.html
for recent report on a relevant study.
In this connection, very relavant are:
(1) work on so-called “junk” DNA, namely, those parts of the sequence biotechies didn’t (at the time the name was given) know the function or purpose of, especially the work by Prof S Krishnaswamy (of BioInformatics Centre, School of Biotechnology, Madurai Kamaraj University, Madurai, India); and
(2) sampling Earth’s upper atmosphere for bio-materials (micro-organisms, rather than molecules) by Indian Space Research Organization some years back, and results from this. The project was instigated by distinguished emeritus Prof Jayant Vishnu Narlikar (founder director of Inter-University Centre for Astronomy & Astrophysics, Pune, India), probably to test Fred Hoyle’s panspermia hypothesis, which was later taken up by Prof Chandra Wickramasinghe.
[I have not really followed these (1) computational and (2) experimental investigations regularly, and beg pardon of the participants if I may have misrepresented some aspect(s) due mainly to my partial cognizance of methods & results.]
I am struggling to see the relevance of the article to the European Union. Perhaps we should define our acronyms here 🙂
The article was getting a bit long to include this bit – but Elykin and Wolfendale also propose that ongoing cosmic ray induced lightning storms may have influenced evolution. The demonstrable production of nitrogen oxides from lightning are (broadly speaking) beneficial for plant life but potentially poisonous to sensitive animal life. This might have skewed natural selection to some extent.
All interesting ideas – though not sure how we might gain any definitive evidence for them.
Thanks, the evolution of amino acid frequency paper is interesting. There are also papers on the actual phylogenetics of metabolism that this should complement. [Sigh, I know I had the reference handy… oh, well.]
Well, yes and no.
Certainly components of these three are among the old main set of pathways. Modern pathways include ice surface freeze-thaw cycles, vent RNA polymerization cycles, Zn world photosynthesis and hydrogen atmosphere polymerization in the ionosphere (like Titan; Earth could have had enough hydrogen excess in the beginning).
But the main divide is between genetics first theories (Darwin, Miller) and metabolics first theories (Wächtershäuser, Mulkidjanian).
The main problem for genetics first theories is that in the absence of chemical potentials selection will result in environmentally robust but non-varying, non-differentiated systems. Modern genetic machinery uses cell metabolism for producing necessary nucleotides.
The vent RNA polymerization cycle is a viable pathway out of that. (Lipid bubbles isolates RNA so it can copy self with variation, eventually evolving metabolic pathways by adopting metabolic enhancement of function; amino acid coupling results in activation with chemical energy.)
The main problem for metabolics first is that in the absence of hereditary enzymes variation will result in inherent leaky and non-selective, non-specific systems. Modern metabolism uses enzymes for suppressing lethal side reactions.
The Zn world photoselective process is a viable pathway out of that. (vent originated but surface near ZnS crystal photosynthesis of organics results in photoselection of proteins, eventually evolving genetic pathways by adopting genetic enhancement of function; nucleotide coupling results in photodispersion of UV energy.)
But so far there is no suggestion of an actual ancestor. In evolution, “chicken or egg paradoxes” points to such ancestry. The proverbial “chicken or egg first” paradox shows that species evolve and that ancestors combined both adult and egg function, by using cell division instead (bacteria world).
In the same way, the “DNA or protein first” paradox shows that there was an evolutionary ancestor that combined both DNA and protein function, by using RNA instead (RNA world).
Now we need to figure out the “genetics or metabolics first” paradox by finding a suggestion of an ancestor that combined both genetic and metabolic function, by some simpler system. Either of the above suggestions (vent RNA world, vent Zn world) would fit, I believe.
Same as always I think, phylogenetic (cladistic) investigation of top down biological pathways, prediction and testing of bottom up abiogenetic theory.
Mulkidjanian et al actually take their Zn world theory and test it successfully on 6 (!) predictions. It is the first tested abiogenetic theory I know of.
Conveniently it goes all the way from photosynthesis of probiotic compounds through protobiotic systems to a meeting with the previous existing RNA world phylogenetic pathway.
Now such theories like the vent RNA polymerization hypothesis must do some heavy lifting to be a realistic competitor.
Thanks TL. Yes, I glossed over a lot there.
I get the impression primeval Adenosine Triphosphate (i.e. metabolics first thinking) is getting some attention at the moment.
http://www.yorkshireeveningpost.co.uk/news/University-of-Leeds-boffins-uncover.6318587.jp
@ dilip.g.banhatti:
I don’t mean to hog the thread but these are personally interesting matters for now.
Douglas Theobald has an interesting take on evolution, as expressed for example in his “29+ evidences of macroevolution” text (available at the TalkOrigins site). He points out that the permutations of the topology of phylogenetics branching structure makes the resulting small set of possible structures from any large cladistic survey, if not locally resolved very well (recent example: are Nectocarids the long sought Cambrian ancestor of all Cephalopods or not), so in large making uncertainty of topology order of magnitudes lower than in comparable sciences.
So yes, the common genetic code (and other common systems) points unequivocally to a last universal common ancestor. Now we know what small uncertainty there remain after testing that.
I believe you have to expand on your points.
(1) Junk DNA, which is a characteristic of eukaryotes only, doesn’t reach back to the LUCA. I fail to see the relevance.
And junk is still junk: we now know that RNA transcripts out of those regions are noisy artifacts of the genetic machinery. They have no important evolutionary relevance.
(2) IIRC there were no positive sampling results.
[Not that it matters for the field :-D, but I have a very dim view on Wickramasinghe et al’s theories.
Not to poison the well, but to explain history as I understand it: Hoyle become famous for his creationist junkyard argument, “the Hoyle fallacy”, as well as for his steady state position long after big bang rejected his theories. His position on transpermia came out of that, and eventually Wickramasinghe adopted his former coworker’s position with a change of rationale.
That rationale is that there were little or no time for abiogenesis on Earth before seeing first life. Now it seems the first real model of Late Heavy Bombardment (LHB) habitability shows that even potentially mesophiles survives, and no reasonable range of bombardment change changed that prediction. (Though I don’t think they figured in putative “crust busters” boiling of all seas. I’ll have to check eventually.)
And we now know that the first zircons from 4.4 Ga were formed in a crust that had a liquid water environment. So likely life could have started well before LHB, and the speedy easiness with which it did so transfers from potential comet or asteroid environments to Earth. Transpermia rationale is now lacking; one could even say that one of its testable predictions, an assumption in this case (LHB non-habitability), is rejected.
Theobald’s work rejects or at least disfavors a population of independent transpermia seeders hammering Earth, and favors an early Earth UCA single biological population origination.]
As usual an enjoyable and well written article.
Being pedantic again: ‘EU’ is not an acronym, merely initials that don’t form a word. Stretching the imagination they could be pronounced to sound like a donkey braying, which would be appropriate for most of the members of said organisation……
@ AndyIv
Thanks for nice feedback – and yes I recall you have raised this point before. I note the relevant wikipedia article ends up tying itself in knots trying to distinguish between acronyms and ‘initialisms’.
http://en.wikipedia.org/wiki/Acronym_and_initialism
I mean everyone seems to accept that SCUBA is an acronym, but as a word it has no meaning other than as being an initialism for self-contained underwater breathing apparatus.
Acronym just sounds better than initialism.
Steve, thanks for another good link. It will come in handy in the Astrobiology course I’m taking.
It’s an impossible area to cover since it still lack a standard theory. I was glossing over things too, as you point out. The chemical potential considerations of some metabolic thinking is a handle that ties into top down phylogenetics and bottom up theory both.
Top down one can see that the Krebs cycle and ATP was a LUCA mechanism. But AFAIU ATP metabolism relies on the cell membrane to store potential energy in a distributed form, the required potential doesn’t even out between reactions.
Bottom up that sets up a demand for a compartment potential to the environment. I’ve seen papers pointing out that all you need to get potential difference metabolism started is a small inorganic compartment that successively can be closed up by semipermeable lipid analogues; the bottleneck pores makes the potential difference grow.
It’s not a coordinating principle since all you can predict is that eventually there will be a cell. The vent RNA cycle theory makes that prediction too, for reason of copy veracity. (Which prediction I forgot to compare the Zn world predictions with in my earlier comments.)
But the upshot is that metabolism first theories may naturally converge on a cell. Combined with something like ATP. (Especially as some phosphate compounds are natural energy carriers in the environment.) That is a little bit of progress, at least.
@ Torbjorn Larsson OM
It’s good to know we live in a world where there are courses in astrobiology. I am envious.
You mean LUCA being the (ahem) acronym for last universal common ancestor.
As you say, ATP metabolic reactions would seem to pre-date membranes. Perhaps membranes came later to increase the efficiency of one or more chemical reactions that just barely managed to power some primeval ‘link this building block to that building block’ event.
Steve, that was the (ahem) acronym I was going for.
I think your hypothesis makes a lot of sense! I’ll save that one for when we come to “Possible chemical pathways to life” (PCPTL, to coin another handy acronym). I hope I’ll remember to make proper credit though, seems life starts after summer vacations. (Yeah, as if!)
Steve Nerlich, these cosmic rays, in what time frame are we talking?
Cosmic rays can create additional electrons which can trigger a lightning storm, but are these storms a few seconds, hours, days weeks???
And you also need a lot of incoming rays in one time to get one lightning-bolt. So I gather that it is not a continuous process since the electrons have time to.move not creating the lightning bolt.
You might all be interested in these other discoveries about proto-life
http://www.newscientist.com/article/mg20627623.000-dna-replication-without-life.html
@ Olaf
Not sure – the authors do quite a lot of analysis around the frequency of CR-induced electron air showers. e.g page 7, they suggest maybe 60 peaks of CR over 10PeV in a 100My period. But that doesn’t really help with determining how long the storms last.
I found this interesting paper on the theory of lightning initiation, known as the “runaway breakdown theory”, written by Aleksandr V. Gurevich and Kirill P. Zybin at the Lebedev Physical Institute of the
Russian Academy of Sciences in Moscow, which suggests that lightning strikes are triggered by cosmic rays that ionize atoms, releasing electrons that are accelerated by the electric fields, ionizing other air molecules and making the air conductive by a runaway breakdown, then “seeding” a lightning strike:
Runaway Breakdown and the Mysteries of Lightning.
Nuts! Where did that premature line break come from?!
I am thinking, a world wide electric storm for a few days or months cause by flooding of x-rays could increase the chance of creating life dramatically.
I believe that both UV light and hot surfaces were also used in the Miller/Urey experiment and both produced amino acids. It’s my understanding that almost any source of energy can work. Certainly lightning has enough energy. However, there’s a vast difference between organic and biochemicals and we’re still relatively ignorant on how the former can evolve into the latter. I personally like panspermia, but, as mentioned, this only puts off the question. Watch for very primitive life on the icy moons and dwarf planets – especially Titan, but not in my lifetime. They could be the seeds of life on Earth.
Sorry Steve, your very last line needs amendment. It should read FREAKING AWESOME.
@Steve Nerlich: Your comment, “I am struggling to see the relevance of the article to the European Union. Perhaps we should define our acronyms here..” LOL! In this web blog, EU has long been erroneously assigned to any theory even vaguely referring to electricity of any sort i.e. “Electric Universe’ theories as I am sure you are well aware?
My initial comment was indeed a ‘poke’ at those individuals who for one reason or another are in denial that ‘electrical’ activity plays any role in our universe. Clearly this article demonstrates otherwise.
Concerning electron air showers… the 2D model you’ve chosen conveys the basic concept well enough as a schematic diagram but does not portray the actual 3D radial structure(s) very well. The electromagnetic shapes generated by cascading electron showers might more closely be represented by expanding spirals. One visualization is that of a hurricane as viewed from overhead. Imagine a spiraling core surrounded by dozens, hundreds or thousands of tornado’s as they spin off outer perimeter clouds.
oTay.then… read a bit of this?
http://www.peter-thomson.co.uk/tornado/Parameters_for_Vortex_Formation_-_Charge_Sheath.html
I was assuming that induced currents might ‘seed’ vortex generation? I used the ‘hurricane’ model as a simple analogy, not as an actual effect from an electron shower.
My apologies if I overstepped.
As Brian Ventrudo wrote in this blog on June 3rd, 2009 in his article “How magnetic tornadoes Might regenerate Mercury’s atmosphere”
“During its second flyby of the planet on October 6, 2008, MESSENGER discovered that Mercury’s magnetic field can be extremely leaky indeed. The spacecraft encountered magnetic “tornadoes” – twisted bundles of magnetic fields connecting the planetary magnetic field to interplanetary space – that were up to 500 miles wide or a third of the radius of the planet.
“These ‘tornadoes’ form when magnetic fields carried by the solar wind connect to Mercury’s magnetic field,” said Slavin. “As the solar wind blows past Mercury’s field, these joined magnetic fields are carried with it and twist up into vortex-like structures. These twisted magnetic flux tubes, technically known as flux transfer events, form open windows in the planet’s magnetic shield through which the solar wind may enter and directly impact Mercury’s surface.”
Venus, Earth, and even Mars have thick atmospheres compared to Mercury, so the solar wind never makes it to the surface of these planets, even if there is no global magnetic field in the way, as is the case for Venus and Mars. Instead, it hits the upper atmosphere of these worlds, where it has the opposite effect to that on Mercury, gradually stripping away atmospheric gas as it blows by.
The process of linking interplanetary and planetary magnetic fields, called magnetic reconnection, is common throughout the cosmos. It occurs in Earth’s magnetic field, where it generates magnetic tornadoes as well. However, the MESSENGER observations show the reconnection rate is ten times higher at Mercury.”
Wow Aqua, two strawmen and both wet; which effigy will you try to burn next?
First strawman: EU crackpots believes that the universe is basically run by plasma effects.
Second strawman: Those who discuss actual science here does not in general deny that EM is a major interaction in the universe.
Without EM there would be no chemical bonds or van der Waal’s forces so no planets, for example. And there would certainly be no life.
Btw, OT but as it is discussed: your topology suggestion out of and in the blue, why would atmospheric electron showers spiral in the weak gradient of the Earth magnetic field density if they are energetic enough to cross the field lines over long distances?
Aren’t you simply confusing these showers with bubble chamber photographs? References please!
Its obvious you didn’t give that link a read.. why do I bother?
It is my understanding that the Miller-Urey simulation is not regarded as a likely model for the origin on complex molecules. The problem is not so much that electric arcs don’t produce organic compounds, as the Miller-Urey demonstrates, but that conditions on the early Earth probably did not match the experiment. So while it is the case that cosmic rays are the catalytic energy for lightning paths, they may not have been the source of organic chemistry for life.
I think that volcanic vents are now the leading theory for the source of pre-biotic chemistry.
I don’t want to get in the EU (not European Union) debates here. However, electrons in the tertiary shower products do not spiral much. They are in the KeV to MeV range of energy and as such they do not respond much to the Earth’s weak magnetic field. The Lorentz force is F = qvxB, B = magnetic field, v = velocity and q = charge, x = cross product. This is equal to the centripetal force for a circular orbit and by Newton’s second law
mv^2/r = qvxB
which for v and B perpendicular we get mv^2/r = qvB. Well now just compute the radius of the orbit r and you get
r = qB/mv
so as v get big (higher energy) the arc becomes large — and in this case very large. The positron does eventually get annihilated by another electron, and electrons in this intermediate energy range are pretty quickly stopped by atomic scattering. So before electrons execute much of an arcing motion they are stopped. Any suggestion these electrons produce currents that cycle around in the upper atmosphere is preposterous.
LC
As always a nice explanation TL and LBC.
I have a question for you. You guys made me curious enough to get into the formulas of Quantum Field Theory. But something funny is explained in the books that does not male sense to me.
Feynman diagram show an anti particle moving against time a normal particle moves with time. This confuses me a bit. It is hard for me to believe that an anti-particle would move against time for real. Maybe it is just a representation only.
This involves CPT discrete symmetry. The discrete operators C change charge of a field, P changes the parity and T the time direction of the field. The product of these operators is CPT = 1. So let us look at CP = T^{-1}, the inverse of T. These operators are as it turns out idempotent, for the inverse also changes the time and so T^2 = 1. To see this in greater detail does require working with a quantum field explicitly, but I will avoid that for now. So an anti-fermion has the opposite charge, such as the positron relative to an electron, and the handedness of the field (partiy) is changed. So to mathematically define an anti-fermion you apply CP to it and this is equivalent to the application of the T operator. So the positron is equivalent to an electron moving backwards in time.
LC
Thanks LBC, I still have a lot to learn. LOL
I also understand now why none of the relativity and quantum mechanics formulas made sense to me, they were shorthand versions of something more complex. I have a very good book “quantum field theory Demystified” But I really should get the other books, they are great.
Aqua your so called tornado’s has nothing to do with the 2D diagram and cosmic rays you claimed to be wrong!
Also according to the European Union, finding magnetic reconnection would be proof that Europe does not exist.
@ Olaf, Given the recent problems with Greece and now related issues in Spain and Italy, maybe the EU will cease to exist. On the currency markets the Euro has taken a bit of a beating.
Aqua, Please, tornadoes have lightning which is generated in much the same way as in clouds. I am not much of a meteorologist or atmospheric physicist, but while lightning is maybe induced by cosmic ray tertiary particles, they are not currents which are direct products of cosmic rays. The GKZ limit on cosmic rays puts a proton energy limit at 10^6TeV, or about equal to the kinetic energy of a golf ball in flight off the tee. A lightning bolt has a lot more energy than that. So lightning is not due to circulating currents from electron tertiaries from cosmic rays.
LC
@Aqua
Thanks – Electric Universe, huh? Hmmm…
Cosmic rays and their subsequent electron showers may act as ‘seed’ generators/fractal initiators for the likes of Sprites, Jelly’s and Blue energy beams and may also seed lightning, ball lightning and tornadoes.
All of these electrodynamic phenom need to be more fully explored before any definite conclusions are made. Never-the-less, they are all very interesting and controversial topics! Mr. Nerlich is very brave in posting the association with the evolution of life which in itself is a VERY controversial subject! I like!
Detractors to open discussion serve no purpose other than personal gratification but are to be expected given the level of consciousness in general on our planet.
Aqua, your link has nothing to do with your 2D graph claimed to be incomplete.
I see a lack of evidences on that paper, just a lots of hyped words strung together creating an logical sounding theory which would fail dramatically when actually testes for real.
Where are his formulas and where are his numbers?
If his theory is sound then he should submit it as a science paper to be tested by other scientists. Did he do that?
Also if you go to the top page of your link you soon discover stuff like:
“Introduction to Gluten-free diets, lifestyle and the coeliac condition”, ” Introduction to low fat and low sugar diets , lifestyle, discussion “,Is there Life on Mars? – Science and Technology….
Aqua it has nothing to do with your claim that the 2D image is incomplete.