Evolution and abiogenesis

[Emily's Cat]

Evolution, as in "T O E", requires an imperfectly self replicating molecule. In the history of life on earth the initial appearance of that molecule probably does not meet our current definition of life; therefore evolution began at a "bright line", but before recognizable life forms were present. What we understand about biological evolution as it currently occurs requires the imperfect replicator. The "evolution as a concept" you are talking about is not TOE.

You are correct; I am well aware that I'm expanding the process to a larger context.

I note your use of "propagate"; that is replication. If it is perfect there will be no variation. Without variation there can be be no "more fit". Thus, imperfect replication is what you describe.

I disagree. I'm using "propagate" to include both replication, reproduction, and persistence of a thing. In that context, the only time you can get nothing "more fit" is if the environment is static. As long as the environment is dynamic, the definition of "fit" will change over time. Realistically, evolution includes both the mutability of the object in question (due to imperfect replication) and the mutability of a dynamic environment within which the object exists. My thinking is that you can still get the "selection" effect of evolution when you have perfect propagation within a changing environment.

Are you aware of an instance of self propagation with accumulated variation leading to evolution which does not involve life as we know it?

Not under the auspices of biological evolution, no.

I know this is a fuzzy blob . I'm more interested in the process than the theory. The theory of evolution that says "characteristics that allow a thing to survive better are more likely to be passed on through subsequent generations". Within that context, the process is confined to genetic replication and heritability.

But if you lift that constraint, the process still works. It's a universe-sized pachinko machine. It's a probability-based filter. A conformation that is more stable will last longer, until the environment changes... then it lasts depending on how well that conformation "fits" the new environment.

It doesn't assume imperfect replication as the only driver of change - it assumes all sorts of interactions between an environment and an object as potential drivers of change. In increase in solar activity increases the number of photons impacting a molecule, and will effect the combinations of molecules that are more stable. Ones that are stable with fewer photons may be less table than a different combination with many photons. Complex molecules that develop and gain stability under extreme temperatures may not be stable when the temperatures drop, because they're exposed to other interactions (like cold) that affect how chemicals behave and interact.

I know there's more to it, and I know I'm missing things. I have a mental map of a relationship and process, that to me seems to be the same as the process at work in standard evolution, but without the same constraints.

I am well aware that I can't produce any math or anything to support this. It is essentially woo from my mindbrain . But I think there's a functional process that is agnostic of the constraints of heritability and replication.

 

[Hlafordlaes]

<happy scissors> Ultimately, we may be the descendants of a 'mineral defect'!

That explains a lot.

 

[TubbaBlubba]

That covers most of solid state science.

Sword makers have 'tempered steel' for thousands of years. Tempered steel is different from untempered steel only because of the defects. A blacksmith often tempers steel by hitting it very hard with a hammer. This doesn't add any element, but it adds complex defects on an atomic level.

Hmm, I think that's "work hardening", not tempering. Tempering is heating the sword to a particular temperature to break down the brittle Martensite formed during quenching into slightly softer, tougher crystals. When you work harden, you typically work at lower temperatures, and you instead get the required hardness and strength through the shaping of the metal, which does indeed introduce defects reducing softness. However, you get far less toughness.

It is how you make copper into something useful for a weapon, however.

 

[Darwin123]

Hmm, I think that's "work hardening", not tempering. Tempering is heating the sword to a particular temperature to break down the brittle Martensite formed during quenching into slightly softer, tougher crystals. When you work harden, you typically work at lower temperatures, and you instead get the required hardness and strength through the shaping of the metal, which does indeed introduce defects reducing softness. However, you get far less toughness.

It is how you make copper into something useful for a weapon, however.

You are right and I was wrong. Thank you!

Work hardening increases the yield strength of the metal my forming complex defects. The defects duct it out!

https://en.wikipedia.org/wiki/Work_hardening
‘Before work hardening, the lattice of the material exhibits a regular, nearly defect-free pattern (almost no dislocations). The defect-free lattice can be created or restored at any time by annealing. As the material is work hardened it becomes increasingly saturated with new dislocations, and more dislocations are prevented from nucleating (a resistance to dislocation-formation develops). This resistance to dislocation-formation manifests itself as a resistance to plastic deformation; hence, the observed strengthening.
In metallic crystals, irreversible deformation is usually carried out on a microscopic scale by defects called dislocations, which are created by fluctuations in local stress fields within the material culminating in a lattice rearrangement as the dislocations propagate through the lattice. At normal temperatures the dislocations are not annihilated by annealing. Instead, the dislocations accumulate, interact with one another, and serve as pinning points or obstacles that significantly impede their motion. This leads to an increase in the yield strength of the material and a subsequent decrease in ductility.’

 

[Skeptic Ginger]

They only have to accumulate. Accumulation creates a direction.

Then what I said wasn't wrong, was it?

You made a false distinction. If changes accumulate, then the direction is determined by what is accumulating.

No, you are making a baseless semantic argument. What I said might have been redundant but that is different from your baseless nitpick.

Natural selection is determines the direction of biological evolution. The direction is determined by 'survival of the fittest'. 'Survival' means accumulation. The inheritable variations that survive accumulate.

Complexity can result from the accumulation of random variations even in nonbiological systems. Crystal growth (e.g., snowflakes) is the best known example of a nonbiological process that develops complexity through accumulation. However, the annealing of crystal defects may in some ways be a better example where complexity grows. Individual defects are probably irreproducible. There are many variations on the slip plane.

Snow flakes don't replicate.

If a crystal is bombarded with high energy radiation, then it develops point defects on an atomic level. Individual atoms are knocked out of position in the crystal lattice, often leaving nearest neighbors alone. Atomic forces are generally short range compared to the lattice constants. Therefore, a high energy particle can knock two maybe three atoms out of position in the lattice at one time. Hypothetically, the point defect is immortal at absolute zero temperature.

Point defects often form while the crystal is solidifying from a fluid. Note every atom sticks the surface in the exact lattice position. So

Point defects include both vacancies and interstitial atoms. Point defects aren't thermodynamically stable. They represents local valleys in the potential energy of the crystal. However, there is generally a peak in potential that prevents them from recombining right away. Point defects have activation energy that prevents them from instantly disappearing. So point defects have a limited lifetime/

Again, the defects don't in and of themselves replicate and accumulate.

Absolute zero temperature is not achievable by the third law of thermodynamics. Defects move around and interact at finite temperatures. No one has been able to achieve temperatures so low that point defects are stationary. They move around and interact. They destroy each otehr by recombining. They catalyze the destruction of other defects. They combine into extremely complex defects that are often relatively stable.

The result is that crystals anneal. Most of the defects disappear over time. Most are destroyed by other defects. However, some defects combine defects that are more stable than the defects that came before them. Some of the defects are more complex than the ones that came before. In fact, the most stable defects are very complex.

There are many recognizable types of defects. Slip planes look like long lines. Some defects look like long corkscrews, spiraling with an atomic diameter. Some of these defects are stable for temperatures below the temperature at which they formed.

The result is that the crystal anneals at finite temperature. Crystal growers often heat the crystal to reduce the number of defects. However, this never destroys all the defects. The defects that remain become more complex.

The result is that most crystals have complex defects that in quasi equilibrium at some finite temperature. The crystal retains point defects, of course. However, these point defects move around at finite temperatures. Stationary defects tend to be very complex.

Atomic scale defects form at very high temperatures. Vibrations knock atoms out of place. So you can't remove defects entirely by heating them. Cycles of heating and cooling make very complex

Few crystals are perfect at achievable temperatures. A few perfect crystals have been made using very complex technology. However, only crystals made of a single element can be made defect free. For example, perfect crystals of silicon have been manufactured. However, crystals made of more than one element can not be made defect free even with the most elaborate technology.

Minerals (i.e., natural crystals) always have defects. without defects. Defects in a mineral are like fingerprints. Every crystal has its own distinct pattern of defects. Defects on an atomic and molecular scale can be identified by various types of spectroscopy.

Complex defects often determine important properties of that crystal. The tempering process creates very complex defects on a molecular scale. Tempered steel is hard due to its slip plane defects. The hardening due to slip plane defects is comparable to the hardening due to carbon and other elements. Iron crystals without defects and impurities is very soft.

So crystal annealing is a good example of a process where 'random variation' together with 'natural selection' creates unique structures of great complexity. Biological evolution is not the only process that creates complex and irreproducible structures.

Whatever.

I don't see anything here that suggests crystal growth and self replicating molecules such as RNA are either both evolving or neither evolving. Only the self replicating RNA can said to be subject to selection pressure and evolving.

 

[Perpetual Student]

Interesting:

http://phys.org/news/2016-08-scientists-billion-year-old-fossil-oldest.html

 

[Puppycow]

I often see people here and elsewhere who argue that the creationists are not entirely wrong when they think that abiogenesis is a part of evolution.

I agree. I don't think it's a part of evolution. It's more of a prerequisite for evolution.

That said, just because we don't know exactly how it happened doesn't mean that it didn't happen.

Mark Kelly Says This 'Exciting' Scientific Find Raises Questions Of Life Beyond Earth

NASA said the discovery shows such "building blocks" of life are "widespread throughout the solar system."

www.huffpost.com

 

[arthwollipot]

There is a branch of creationism that says that God created life, but it evolved naturally from there. Abiogenesis isn't actually a necessary prerequisite for evolution. Abiogenesis by definition rules out supernatural creation, but evolution doesn't care how life got started, only that it did somehow.

 

[Puppycow]

Sounds dubious, but OK. I could go for a theory that God created the universe and all of the natural laws that govern it, but didn't actively intervene after it was all set in motion at the very beginning. But if he "created life" I think that's how it happened. Not some later supernatural act.

ETA: I should add that such a theory may not be falsifiable, and is thus probably beyond the realm of science. You are free to believe it or not believe it, but you cannot prove it or disprove it, or even gather any evidence for or against it. Because under this theory, God hasn't intervened and probably won't ever intervene, since the creation, and doesn't communicate with us.

 

[arthwollipot]

Because under this theory, God hasn't intervened and probably won't ever intervene, since the creation, and doesn't communicate with us.

Oh, under the evolutionary creationism paradigm I described, God certainly can intervene and communicate. Miracles exist and the Bible describes real events. God just doesn't intervene in the evolution of species.

 

[Puppycow]

Oh, under the evolutionary creationism paradigm I described, God certainly can intervene and communicate. Miracles exist and the Bible describes real events. God just doesn't intervene in the evolution of species.

OK. I'll just say that I think that's a very dubious theory and leave it at that.

 

[arthwollipot]

OK. I'll just say that I think that's a very dubious theory and leave it at that.

I wasn't proposing that it was watertight, just that it was something that some people adhere to. Francis Collins, for example, said that "evolution is real, but that it was set in motion by God".

The idea is that humans evolved naturally, but God created their souls, without which they would have no moral sense and would be little more than advanced monkeys.

 

[EHocking]

Sounds dubious, but OK. I could go for a theory that God created the universe and all of the natural laws that govern it, but didn't actively intervene after it was all set in motion at the very beginning. But if he "created life" I think that's how it happened. Not some later supernatural act.

Yabbut there were numerous supernatural acts post creation. Not the least creation of modern man, as is, no evolution leading to h.sapiens.

ETA: I should add that such a theory may not be falsifiable, and is thus probably beyond the realm of science. You are free to believe it or not believe it, but you cannot prove it or disprove it, or even gather any evidence for or against it. Because under this theory, God hasn't intervened and probably won't ever intervene, since the creation, and doesn't communicate with us.

The pope would tell you otherwise.

It’s a theory not worthy of consideration.

 

[Emily's Cat]

There is a branch of creationism that says that God created life, but it evolved naturally from there. Abiogenesis isn't actually a necessary prerequisite for evolution. Abiogenesis by definition rules out supernatural creation, but evolution doesn't care how life got started, only that it did somehow.

Abiogenesis doesn't necessarily include a deity, it's just the point of transition from non-living to living matter. Probably not a bright line, but still a transition to life. Abiogenesis is actually a prerequisite for evolution - evolution only applies to organisms that have genes, and to date those are all living organisms .