Saturday, March 14, 2015

Letting Go of Abiogenesis

In an earlier post in regards to standard evolutionary synthesis, my point was that simple "natural selection" on "random" mutations fails for the very Darwinian reasons the idea originated from. If it ever was the primary mechanism, it would have died out quite quickly from obviously superior mechanisms (that are, nevertheless adaptive in the same intuitive sense for reproductive success). At least, that is my conclusion and thesis.

Looking at a particular *new* *beneficial* mutation that one time or another has to happen on a path to some species to another more adapted to a particular environment, the probablistic difficulties are similar in scope to what is envisaged in abiogenesis, but of course, having working and sophisticated superior mechanisms already in play is different from something where you really only have the laws of physics, chemistry and probability as envisaged with abiogenesis.

All efforts to demonstrate in principle either backwards from the simplest life we know, or forward from the most complex non-living carbon based systems we can imagine, have come up with a blank. It reminded me of the difficulties and paradoxes with Euclid's fifth Axiom, and also the paradox with measurements of the speed of light being constant at different relative speeds. Most who research abiogenesis in some way or another don't perceive the paradox so much as it being difficult to conceive and not having evidence to lead you in any way or another to point in the right direction.

My idea was to, like mathematicians in their time, presuming Euclids fifth axiom false, or Einstein in his time, presuming the speed of light to be constant at all relative velocities. If one presumes abiogenesis as currently framed to be not just difficult, but actually impossible, where does that leave us with naturalistic possibilities with the origin of life?

My idea was to make this a bold falsifiable theory, and hope that some evidence would actually bear on it to rule it out or not. Certainly it makes perfect sense to me, but I want to give all support and aid anyone who thinks it can be proven wrong by some experiment or new observation.

My alternative to a process of abiogenesis to go from no life to chemical life, is instead that chemical life is designed (in an evolutionary process of design) by a life form which is not directly chemical based. I was thinking along the lines of Hoyle's dust cloud life as something at a similar place in idea space. My other thought was that the proximal antecedent to chemical life would use its own life cycle as a kind of template for the first independent living cell, which would have to be something like an amoeba.

When I first saw the image of Hartley 103P with these abiogenesis ideas in my head, I felt that comets were the only real candidate for life's proximal antecedent. Over spans of thousands to millions of years, they use the interplanetary superhighway to move from orbit to orbit expending very little relative fuel. To reproduce, they expend a great deal of energy speeding up their spin in a controlled way, stretching into a bilobed shape then continuing the spin up and stretch until it is two almost independent bodies tethered by a long skinny neck, which tidal alignment would easily sever "the umbilical cord" and the two separate comets would go their separate ways.

In light of this, for most of their lifespan, comets would be completely "dormant" and essentially invisible. Thus dark "asteroids" like Bennu, which is likely to be visited soon enough should have almost all the same features as comets, bar the outgassing. The distinction between live/dormant comets and 
dead asteroids would come down to colour - the lighter they are, the less likely they are to be just dormant, and features dominated by impacts rather than cometary flaking/stretching/outgassing would be a "dead" giveaway.

Anything opposite to this, I would feel would easily falsify my hypothesis. It being based on assuming abiogenesis as currently framed impossible, and comets being the proximal biological precedent. The former being broadly "M life theory" and the latter "living comet theory"

Quite frankly, I'd be very satisfied if they were falsified - my investment in the theories is based on an unshakeable hunch that they are right. I want to find evidence that they are wrong - please help me.

4 comments:

Chris Fellows said...

They are inanimate lumps of stuff. Splitting is not reproduction, if the segments that are split do not grow. There is no 'cycle' in your postulated life cycle. I am certain comets are good *places* to look for things that might be proximate, or per-per-per-proximate, forms of life not as we know it, especially if they have formed as fragments from a larger body. But to speak of them as M-Life, or X-Life, or Omega-Chi-Delta-Life, or whatever, is simply to drain the word 'life' of any useful meaning. IMHO.

Marco Parigi said...

If you could formulate your response in something close to a statement that falsifies my thesis rather than a quibble that I'm fiddling with the meaning of life. The comet splitting is a tiny part of the life cycle, like the splitting of a seed pod into two pieces. Yes- all the interesting things that are chemically and functionally like LAWKI are protected from space deep inside the comet. We can only know what is in there from inference from the outside. All our inferences are based on what we think ought to be in there. Give me any piece of evidence that they are even "inanimate" however you define that. I see that comets are dynamically altering their rotation state in a way consistent between different comets. Compare that to an asteroid and it doesn't sound inanimate can be proven yet for comets as it can be with asteroids. There ought to be a statement that could falsify "animacy" of comets.

Anonymous said...

If you could formulate your response in something close to a statement that falsifies my thesis

= Splitting is not reproduction, if the segments that are split do not grow. There is no 'cycle' in your postulated life cycle.

Marco Parigi said...

I was thinking more along the lines of a point of data we could point to (or a likely future point of data) that if it was the expected value, would despatch living comet theory to the dustbin. Two came to mind well before Rosetta rendezvoused with 67P, racemic organic molecules on the surface of the comet, and falsification of stretch theory (even falsification of continuing stretch) . Either of these(expected before rendezvous) observations would have me concede that living comet theory was fanciful. However, the opposite does not mean living comet theory is proven, or even likely. Just that chiral comet molecules and continuing stretch would allow me to persist with my hunch and my search on how to disprove it next.
Unfortunately, I cannot think of a bit of data which can categorically disprove a life cycle. Even if we limit ourselves to comets only ever growing(accreting) from a molecular cloud it doesn't falsify a cycle. If comets are still splitting and spreading their smaller seed, they could be waiting for the spread cloud of cometlets to meet up with a new passing molecular cloud so that they could grow again and spread even further, infesting planets as well, panspermia style.