The code that is DNA

[Foxaèr]

I think Feynman said something like "I prefer to say that I don't know, than to have answers that might be wrong."

Well, you know me, instead of attempting to search for a quote that someone else stated to express what I already know is not my style.

[Mister Agenda]

I emphasize once mostly because evolution always attempts to trace ancestry to a single common ancestor for all life. Rarely do you hear someone suggest multiple lineages emerging from separate origins of life.

That's because we haven't found any evidence that suggests multiple lineages. It's no problem for the theory of evolution if another lineage were discovered, as long as it follows the same biological rules as the one lineage we know of. Yes, there may be multiple lineages, but that suggestion has little value if we can't find them. It's possible that life started more than once but only one lineage survived the early stages. We just don't have any evidence/observations to support that hypothesis. It's easy to imagine a 'first come, first served' scenario though, where once even microbial life becomes abundant, any life in the early stages is simply devoured unless it's completely isolated from already extant life.

[John 6IX Breezy]

I agree. Although I don't know if I agree with the first come first serve narrative. We, as living beings, are still stumbling across entire species we hadn't discovered yet, billions of years after the fact; we're even finding new isolated tribes of our own kind. Earth is big enough that entire populations can thrive under our noses without being devoured.

If life emerged multiples times, there's enough distance in the world for multiple lineages to have emerged. Even puddles a few inches (centimeters) apart, are a solar system away at the microscopic level. Life is rarely at each others throat. By devouring do you mean in the competition sense, by devouring each others resources? Or do you mean actually devouring, in the carnivore prey/predator sense?

[Peebothuhlu]

I agree. Although I don't know if I agree with the first come first serve narrative. We, as living beings, are still stumbling across entire species we hadn't discovered yet, billions of years after the fact; we're even finding new isolated tribes of our own kind. Earth is big enough that entire populations can thrive under our noses without being devoured.

If life emerged multiples times, there's enough distance in the world for multiple lineages to have emerged. Even puddles a few inches (centimeters) apart, are a solar system away at the microscopic level. By devouring do you mean in the competition sense, indirectly by devouring each others resources? Or do you mean actually devouring, in the carnivore prey/predator sense?

Uhm... the 'Sense of scale' in your comment is just a tad 'Off'.

Everything we're finding/discovering is still all within the same biology.

Also the planet itself has 'Re-mapped' its surface a number of times since life started multiplying. Not counting the events which nearly cleaned life OFF this rock.

So there's almost been a couple of 'Resets' in the millions of years since our oblate sphereoid coalesced, but I digress.

So, speaking as a complete lay-man, once a certain DNA (Three base pairs. Right handed chyralty etc) type became 'The majority'? Then, yes, pretty much everything else became 'Food' for it and was (For want of a better term) eaten to extinction.

Actually... 'If' the "RNA world" hypothesis is correct then, litterally, the DNA world of today made the previous biology 'extinct'.

I remember hearing/reading some where that life derived organic molecules are so ubiquitous/abundant on Earth that major efforts are neded to completely 'Sterilize' basic water etc so as to remove all traces/taints of such things so as to not comtaminate further/new experiments.

One of the reasons for going out and exploring places like Io etc is to see if there might be a biome that's completely alien compared to that of Earth.

Cheers.

Not at work.

[John 6IX Breezy]

Uhm... the 'Sense of scale' in your comment is just a tad 'Off'.

Everything we're finding/discovering is still all within the same biology.

[…]

So, speaking as a complete lay-man, once a certain DNA (Three base pairs. Right handed chyralty etc) type became 'The majority'? Then, yes, pretty much everything else became 'Food' for it and was (For want of a better term) eaten to extinction.

Actually... 'If' the "RNA world" hypothesis is correct then, litterally, the DNA world of today made the previous biology 'extinct'.


Not at work.

Hello, I'm not sure I understand why my sense of scale is off on account of such findings emerging within the same biology. I don't understand why DNA would make RNA go extinct back then, when DNA is currently transcribed to RNA in our cells, and there are still microorganisms in existence with either RNA or DNA genomes.

I'm also not sure that microorganisms, even today, are eating each other in such a way; that's why many bacteria are grown in cultures made of agar, sugar, milk, etc. They mainly derive their energy from other chemicals, or light, etc. So I think the "eating" analogy would need to be better substantiated, or explained better at the least. I haven't looked into the RNA World hypothesis beyond a video someone posted a few weeks ago.

[Peebothuhlu]

Hello, I'm not sure I understand why my sense of scale is off on account of such findings being within the same biology.

I'm also not sure I understand why DNA would make RNA go extinct back then, when DNA is currently transcribed to RNA in our cells, and here are still microorganisms in existence with either RNA or DNA genomes.

So.

Life has been on the planet for an estimated (Outside edge) 4 and a half BILLION years.

That is a 'Long' time. In that time the surface of the planet has, litterally, reshaped itself through continental plate tectonics.

So, pretty much every place on the planet has been every where else.

So, once really basic bio chemistry got started and spread.... It's been spread every where simply due to tectonic plate movements over such a long time. There are no 'Pristine pockets' any more. Everything has been smeared around.

You don't see South American 'Terror birds' any more because land connections changed and new, better competing species arrived and simply, effectivly, 'Ate' them into extinction.

The only reason we have a plethora of marsupials to marvel at is because that continent has remaned geographicaly isolated for such an amount of time.

But, at a fundamental level, everything today is still the same, basic DNA copying around.

The 'RNA world' hypothesis is that, innitally, there was no DNA.

ONLY RNA. a form of RNA did everything/was everything. All the cells (Or what have you) were nothing BUT RNA scrolling about doing its thing. RNA was making the bits that were making the bits that were forming the early 'Cells' etc.

Then... DNA got put together. It was better/quicker/*Insert proper technical term here* at making more DNA and so it simply took over.

Potentially 'Eating' the RNA competitors around it untill all that was left were competing DNA type things.

Now, if you look about, do you see anything to indicate a 'Pocket' of that lost RNA world? No, you don't.

RNA is only found as a.... sub set... of the greater DNA biology of today.

Cheers.

Not at work.

[John 6IX Breezy]

So.

Life has been on the planet for an estimated (Outside edge) 4 and a half BILLION years.

That is a 'Long' time. In that time the surface of the planet has, litterally, reshaped itself through continental plate tectonics.

So, pretty much every place on the planet has been every where else...
Not at work.

Well, I think the fact that there are marsupials in the Americas goes with your point about shifting surfaces. They're not all isolated to Australia, presumably because of those shifts. However, I think this overall idea of spreading goes against your point. Competition, it seems to me, has a greater effect within such pristine pockets. By restricting life to smaller location, resources are limited, and it makes sense for competition to have a more magnified effect. But if life is being spread all over, it allows for greater resources, and less competition.

The idea of DNA eating RNA is still a bit obscure. I've forgotten how DNA replicates; but in terms of doing anything else (primarily building proteins) it needs RNA to do it. Perhaps there is some bacteria that skips RNA and can go from DNA to protein; but in our bodies RNA is equally important to DNA.

[Peebothuhlu]

Well, I think the fact that there are marsupials in the Americas goes with your point about shifting surfaces. They're not all isolated to Australia, presumably because of those shifts. However, I think this overall idea of spreading goes against your point. Competition, it seems to me, has a greater effect within such pristine pockets. By restricting life to smaller location, resources are limited, and it makes sense for competition to have a more magnified effect. But if life is being spread all over, it allows for greater resources, and less competition.

The idea of DNA eating RNA is still a bit obscure. I've forgotten how DNA replicates; but in terms of doing anything else (primarily building proteins) it needs RNA to do it. Perhaps there is some bacteria that skips RNA and can go from DNA to protein; but in our bodies RNA is equally important to DNA.

*Sigh*

Okay.... my point in regards to mentioning the marsupials was as an illustration (Like me mentioning the terror birds) of how one biome over runs and errradicates another biome. Leaving aside that the underlying, fundamental biology is still the same between monotremes, marsupials, mammals etc.

So... how are the monotremes doing in the rest of the world? To highlight an even more obscure lineage that's managed to hang on thanks to continent spereration.

Again, with the DNA/RNA thing 'Hypothesis'.

At one point there was nothing BUT rna. That's all there was floating around. Taking in basic chemistry and converting it into more/further rna.

THEN, some how, DNA came on the scene. Maybe some rna smooshed together in just the right way *Shrug* but there it was.

DNA, being better than RNA at doing the replicating/surviving thing simply became ALL there was in/by way of organic chemstry. With RNA only remaining as a 'Stub' within the chemistry of DNA replication.

Cheers.

Not at work.

[John 6IX Breezy]

@Peebo-Thuhlu

Idk I'll have to look up a paper on it later, your metaphors are throwing me off lol. If RNA smooshed together to create DNA, that's a different idea from DNA emerging separately and eating RNA. I also wouldn't consider RNA a stub within DNA replication, so.

@Mister Agenda

I'm also curious to know if you think evolutionary biology could indeed distinguish separate lineages derived from distinct origins, that have otherwise similar structure? In other words, if two organisms share gene A, is that enough to know they absolutely have a shared origin? There are only so many elements, and perhaps life can only emerge in so many ways. Crystals don't have a shared ancestry, but they all have a shared structure. I would assume that if life emerges multiple times, it does so with rather similar structures. My point is, I think shared origin is an assumption evolution broadly makes. I'm less certain it is a fact that evolution can establish.

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To any moderators reading, is @ enough to tag soneone? Or are they only notified if you go through the reply feature directly?

[Peebothuhlu]

At work.

@Peebo-Thuhlu

Idk I'll have to look up a paper on it later, your metaphors are throwing me off lol. If RNA smooshed together to create DNA, that's a different idea from DNA emerging separately and eating RNA. I also wouldn't consider RNA a stub within DNA replication, so.

@Mister Agenda

I'm also curious to know if you think evolutionary biology could indeed distinguish separate lineages derived from distinct origins, that have otherwise similar structure? In other words, if two organisms share gene A, is that enough to know they absolutely have a shared origin? There are only so many elements, and perhaps life can only emerge in so many ways. Crystals don't have a shared ancestry, but they all have a shared structure. I would assume that if life emerges multiple times, it does so with rather similar structures. My point is, I think shared origin is an assumption evolution broadly makes. I'm less certain it is a fact that evolution can establish.

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To any moderators reading, is @ enough to tag soneone? Or are they only notified if you go through the reply feature directly?

People are only notified if you 'Quote' them.

Yes... I'm kind of deliberately being colloquial on account that I have no real expertise and but the most basic understanding of the subject.

Again.

The first 'Life' is hypothesized as to being RNA.

With our current form of 'Triple base paired DNA' taking over/supplanting the RNA.

However like the scattered remnant examples of monotremes, marsupials, Wolomi pines etc RNA still lingers about.

Another thing. All life on Earth uses a triple bonding pair of genetic molecules.

You could get away with two base pairs. But this would lower/limit the amount of protiens you can create.

Or you could have four or even five base pairs.

Heck, pretty sure if you went up to five you'd be able to create every protien currently known.

Cheers.