In general I agree 100% with your debunking the idea that (bio-)evolution has a particular direction.
But, here we clearly *require *that chem-evolution drive from the simple towards the complex. That’s how we end up first with methane, then alchohols & simple sugars, and eventually amino acids, proteins, and finally DNA & such. And each of those movements is (AFAIK) energetically disadvantageous.
We *require * this only because in the beginning there were only simple elements. And now there are complex molecules. And time goes only forward.
Clearly the process could have had (and probably did have) hundreds of blind alleys and retreats along the way. And nobody or nothing was directing it. And by this point in time it could have resulted in millions of different configurations other than the one we see today.
But the end result we *do *see today has been a process which *has *climbed up the entropy slope against the brute beast physics of heat & energy.
The “why” can be simply due to random chance. My question is the “how”.
As I read the OP, he assumed the how was immaterial and the why was fore-ordained as “progress”. And that’s what I was objecting to.
Darwin is not the only or last word on evolution, just the first. We’ve discovered a lot more about it since then. Natural selection isn’t the only mechanism for evolution. There’s genetic drift, for example.
If we are going to do without God, we need to explain how life originated whether we call it evolution or not. There was some work I believe in the 60’s where they prepared a likely primordial soup and zapped it. They failed to prove life could have originated that way. That doesn’t prove it couldn’t have or didn’t. Maybe some day a better designed experiment will work.
My personal belief is that Godchoose to create the universe in such a way that does not require divine intervention. He does not want to prove his existence by the changes in the rocks of the earth, but the truly hard places, the human heart.
Let’s keep this discussion in GQ by sticking to the scientific aspects of the question. If you want to discuss your religious opinions, other forums are available for that.
One way you could look at it, is any system which is such that biological evolution can work on it could itself be defined as “alive”, and thus past the point of abiogenesis.
That’s the Miller-Urey experiment cited in entries #6 and #7 above. There’s been much work and speculation since then, mas you can imagine.
My favorite explanation of it is Julia Child Shows You How to Make Proimordial Soup
It really IS Julia Child. and it really is the Uray-Miller experiment:
I think what is wrong is that no one has, so far, proposed a plausible mechanism for the evolution of anything we might call living from a chemical stew. Not saying it can’t be done, I would even suppose it will be, but not in my lifetime.
For every biological system, there are plausible mechanisms by which evolution could take place. Take the eye, for example. Some chemicals are photosensitive. I can certainly imagine that one appeared at some point. It was useful for some purpose, probably unknowable now. But at some point, the organism it was in “discovered” (really some distant descendant discovered) how to use it to detect the presence of light. So a primitive eyespot evolved. Then, some mutation put the eyespot into a concavity in the cell. The detection of light became more sensitive. Then this cavity became more pronounced and covered with a transparent membrane. Lots of detail omitted. But the point is that at each stage the new organ functioned just a bit better than before until we had eyes. I once read that the eye evolved independently between 40 and 60 times.
No such plausible story has been created for the evolution of life in the first place. Until there is one, we do not speak of the evolution of life.
I think this is the most important point. We understand pretty well the mechanisms of how evolution takes place in living organisms, although details remain to be resolved. We don’t have any clear understanding of the processes of biochemical “evolution” that led to the origin of life in the first place.
The fact that life exists here on earth is not evidence that there has to be a step by step chemical process favored by non-living characteristics which impel massively iterative process toward some sort of self regenerating set of life precursors. The coincidence that we happen to live where it happened doesn’t mean it is more likely that it can happen elsewhere, since our existence requires that coincidence as a necessary precondition. Every other environment within our observational capabilities at present does not have life, nor any compelling evidence of ever having had life. (Mars meteors are, in my opinion, far short of compelling evidence.)
Abiogenesis remains a unique case in the universe, by current observation. This fact does not mean it is not possible, or even inevitable under certain key conditions. It simply isn’t evidence either way. Fifty terrestrial planetary environments without life would not be proof that it was not possible. Nor would fifty thousand. One case of life of provable extraterrestrial origin would be strong evidence that such an abiogenesis mechanism does exist.
Unfortunately, for the argument we are not to mention here, it would not be evidence that God did not exist, only that other Gods or other plans by one God might. But I am not saying that. Oh, no, not me.
My point is that evolution is about the diversity of species, not the origin of life. Evolution can be true whether life arose by natural processes or by miracles.
Hell, even abiogenesis isn’t incompatible with the existence of God. If I were omnipotent, I’d create life by expertly setting up initial conditions so that it could generate itself from non-living substances, then go fishing for a few billion years, coming back when there was something interesting going on.
I don’t really see why that matters to the question of whether or not the process occurring can be described as evolution.
Fair enough - although I’m still not sure we’re on the same page - if there were millions of candidate configurations, then the event that caused one of them to prevail is selection (doesn’t matter how insignificant were the selection criteria). Then it’s evolution. If the candidate configurations were self-replicating, then there will be variation, competition, selection.
I’m not really sure why people are hung up on the idea that evolution is a biological process. It just isn’t. It’s a process that happens to manifest in biological systems, but that doesn’t make it an exclusive property.
Any system is likely to exhibit evolution, if it has:
Self-replication of member entities (with inheritance, but with imperfect copying)
Some kind of selective pressure (limited resources, environmental conditions, etc)
That system can be a collection of biological organisms on an island, it can be algorithms in a computer, it can be chemicals (that we do not qualify as living organisms) in a pond.
If you dive down deep enough, biology is chemistry also, though in many aspect the chemistry part is abstracted out to allow us to examine a piece of it. But Watson and Crick’s work was more chemistry than biology.
The crucial question is: what is the simplest self-replicating molecule which we could expect to randomly form given the conditions of the early earth, and the ingredients to be found there? Once we have that, is there a plausible evolutionary path to more complex self-replicating molecules, and eventually to RNA. Clearly this is not what Darwin was thinking of, but if you consider evolution “descent with modifications” paired with some sort of selection, it falls in very nicely. That’s the wonder of evolution - the concept is so simple, yet so powerful that it could be applied to this also.
The Teaching Company has a lecture series on the origins of life that was pretty well done. The lecturer (Hazen, I think his last name was) explained in pretty good detail all of the current theories that people have come up with about the origin of life, complete with a discussion of their strengths, weaknesses, and an assessment of how much or how little experimental evidence there is, and what experiments were being planned. Well worth a listen, if you can get ahold of it.
What it certainly would be fair to say is that the origins of life cannot be explained in terms of the detailed mechanisms (genes, etc) that make biological evolution happen in living systems - because the details are different, even if the principles are the same.
Evolution requires that traits be inherited by offspring. The mechanism for handing down those traits is DNA or RNA molecules, which you don’t have if you don’t already have life.
Actually early spark tube experiments showed that 20 amino acids could be created from inorganic precursors. We also know that comets, which rain down on us quite frequently, have all sorts of organic compounds pre-made.
If evolution is just the creation of traits that encourage survival it should. My understanding of both replicator first and metabolism first origin of life theories is that some replicators and/or metabolisms were better at it than others, and became more prevalent. Dawkins made his intro to his book the selfish gene a story about how he felt this occured in a replicator first model.
But you still have the question about when, where and how the first replicators and metabolisms showed up.
Personally I wonder if both metabolisms and replicators occured simultaneously and just merged together into one organism and eventually became prokaryotes (rather than a replicator inventing a metabolism or vice versa). Eukaryotes are supposedly just independent prokaryotes that merged, and multi-celled organisms are eukaryotes that merged. So I wouldn’t be surprised.
If we’re all just reacting - heck, if our bodies are just nuclear waste - then what? Where’s the original reaction? That’s what Creationists can’t grasp. No one can. It’s called prehistory for a reason. It isn’t even a rational thought, really.
