How complex can a self replicating component within a virus or cell be if initially it is formed by accident?

The crux of the matter is this: How did life happen?

what developed inside of the organism that made it want to replicate — christian2017

Nothing. They don't "want" to reproduce, they just do. For that matter, it isn't entirely clear that the higher animals "want" to reproduce; they just do. Females get pregnant because fucking makes males feels good. It might even make females feel good. Reproduction follows because it does (the machinery kicks in), not because the two agents involved wanted it to happen (at least below the primate level). As far as I know. I could be wrong. Maybe lions, tigers, and bears--vultures, snakes, and lizards-- really do WANT their little offspring running around.

This is also true for single cell plants and single cell animals — christian2017

Many/most single celled creatures in the Archea group (that were neither plants nor animals) didn't even need sunlight. All they needed was a minimal amount of H2O and chemicals from which they can derive energy. There are extremophiles found in very deep rocks that haven't seen the sun for ... hundreds of millions years. There are extremophiles living in very hot ocean floor vents that don't need the sun either.

The blue-green algae that could benefit from sun light and could change CO2 into O and carbohydrates wrecked the stable environment that earth had been perfectly happy with for a very, very long time. The excess O poisoned everything else.

Whether virus-type-structures existed before bacteria is hard to say. Viruses as we know them definitely came later; we know viruses as obligate intracellular parasites--so the bacteria had to come first. But the viruses could have moved in later, even if they existed first.

The viruses we know all have the genetic material to take over the cell, so again, those bacteria definitely didn't come first.


We don't know how life started -- you and I, for two, weren't there when it happened. It all probably began as some sort of crypto-life that just wasn't quite biology yet, but was capable of forming some stable boxy structures. But it's a very long way from stable boxy structures to stable boxes that are able to keep themselves nourished and are able to reproduce -- something they just do, without any desire--as far as I know.

I know intelligent people who managed to reproduce without actually wanting to do so. Fucking felt good, and then there was a baby. "Fuck!" they said.

:rofl:

I understand why larger creatures are driven towards sex and reproduction. However reproduction requires structures with in the cell or virus that makes that cell or virus split itself into two.

When the cell formed randomly, how and why did a separate structure that made the animal (single cell) split or reproduce?

I don't know. The question you are asking goes back to the beginning of life on earth. Once a cell formed, however randomly, accidentally, or purposively that happened, there had to be a way for that cell to make more of itself OR life would have amount to that one, single cell, and that would have been the end of the story.

We could guess that the initial method of reproduction was reproduction through cell division: the cell dust divided itself or got divided and then there were two, then 4, then 8, then 16, then 32, 64, 128, and so on. There was some development over tine: Some sort of genetic pattern developed, and more than one kind of cell came into existence. Prokaryotic cells (E. coli for example) do not have nuclear structures--the chromosomes aren't clustered into a structure (the nucleus). Eukaryotic cells (creatures like you) do have a nuclear structure, and your nucleus divides before the cell divides.

But again, your question goes back to the beginning and nobody was around to observe what (or how) it happened, or nip it in the bud. Nobody was in the lab at that moment to pour the first cell into a bath of acid to make sure nothing like that ever happened again.

The kind of cell division that goes on after an egg is fertilized (mitosis) didn't happen right away. It took millions (billions) of years for that system of reproduction (sperm, egg, union, cell division into new complex organism) to develop.

When you say nuclear, what do you mean by that?

My understanding of nuclear is that all cells consist of nuclear elements (most matter in addition to that).

We could guess that the initial method of reproduction was reproduction through cell division — Bitter Crank

There is an even more basic method of reproduction, and that is what a lot of origin of life research focuses on: self-replicating molecules, which are fascinating yet entirely "mechanical" (or in this case chemical) things. Going up the scale there are more complex self-replicating systems, which still don't require anything as complex and anthropomorphic as desires and intentions to work.

Origin of life (OOL) is a fascinating field of study. If you have an interest, there's lots of material that you can read, from short online articles to entire books.

I don't know if it is possible to explain with words but can you explain the model referred in "There is an even more basic method of reproduction". Or describe that specific model if possible?

"Nuclear" here refers to the "nucleus" of the cell. The nucleus is a sub-cellular structure that contains the organism's genetic information. The genetic information is packed into smaller structures, "chromosomes". The nucleus of a cell and the nucleus of the atom are two altogether different things that just happen to have the same name.

It's been a long time since I had a basic biology class. The structures of the cell, and the DNA, all get very complicated.

What SophistiCat was referencing was this:

About 3.8 billion years ago, the earth solidified into rock. There was water, rock, and a mixture of gases. No life. After about 3.5 billion years ago, there was apparently life of some sort. How did we get from "no life" to "life"? The theory goes that were molecules that could form duplicates of themselves. They could do this because of their natural physical and chemical properties. Self-duplicating molecules doesn't require an outside agent or any "intent" to duplicate. The molecules just did what they could do. The molecules could also link up, which is also natural. Self-copying, linking-up molecules got more complicated. At some point in the long stretch of time, the self-copying, linking-up molecules became something we would call "life"--that is, the life forms were able to become more elaborate, maintain themselves, and duplicate their more complex form.

We don't know where on earth this all happened. It might have been inside rock, in thermal vents, in hot slop--we just don't know. But it did.

"Desire", "intent", "a plan", and so forth just don't figure into life at this point. Chemistry and physics governed life on earth. Whether physics and chemistry still govern life on earth (including us paragons of animals) is the heart of the debate about free-will and determinism. But even if one is an ardent believer in free will, one need not think that single celled life had a will. Will presumably requires a complex brain capable of making independent decisions rather than just being a wet robot.

Some people think we are wet robots; some people think we have free will. Maybe it's a mix -- I don't think there is a definitive answer. Since we are immersed in the problem, we can't give an objective answer.

Here is an article from the New Scientist that talks about self duplicating molecules and life.

Think of self replication as a special event because it causes an infinite chain reaction going forwards in time. Once self replication is established, there is no going back,

if self replication occurs (assuming no god like entity) and it stops then it stops for x amount of time into the future. How a scientist would prove replication can occur naturally is up in the air.

Self-duplicating molecules doesn't require an outside agent or any "intent" to duplicate. — Bitter Crank

that would be hard to prove. The initial self replicating "creature" or cell is a mystery to scientists. Some say cells or single cells are what formed the water on the earth.

Alot of what scientists say about this original self replicating "creature" or cell is conjecture.

that would be hard to prove — christian2017

About as hard to prove as claiming that the cells, molecules, etc. DID have intent.

Some say cells or single cells are what formed the water on the earth. — christian2017

And by what means do those "some say" claim that these cells would have produced all this water?

H2O is native to the pre-earth solar system. The comets, rocks, and icy objects in the Oort cloud (and closer) are as old as the solar system, and they have been out there as ice for 4 to 5 billion+ years. When the solar system was much younger, earth was bombarded by both rocky objects (like the big one that hit the earth and created a liquid rock splash that made the moon) as well as many, many icy objects. The icy objects are probably how we got oceans of water.

Jupiter's large gravitational field probably helped things along by pushing/pulling/throwing a lot more objects into the orbits of the 4 inner planets than would otherwise have been here. Mars seems to have lost a lot of its water (it wasn't quite large enough to hold on to its atmosphere) and I don't know what happened to Venus. Maybe Venus was too hot. Not sure what Mercury's situation was either.

Alot of what scientists say about this original self replicating "creature" or cell is conjecture. — christian2017

Of course it is conjecture -- there were no eye witnesses and there are no fossils from back then. However, the theory does rest on more than blue-sky conjecture.

Of course it is conjecture -- there were no eye witnesses and there are no fossils from back then. However, the theory does rest on more than blue-sky conjecture. — Bitter Crank

I doubt it.

As for the water thing that was verbally told to me. I don't have any evidence at this point and i may never have evidence for that.

As for the water thing that was verbally told to me — christian2017

As the old saying goes, "Don't believe anything you hear and only half of what you see."

You doubt that the theory rests on more than blue sky conjecture? I have no objection to your doubt. It's a free country [so they say]; think what you want! It has nothing to do with the price of tea in China whether the water came from Oort Cloud ice cubes or clever bacteria.

thats fair