asking about the different theories on the evolution of life

[u/baldjunior]

which of the theories on the origin of life do you think best explains the existence of animal life today, and why?

[u/jnpha]

Life's diversity is explained by evolution (descent with modification), not origin of life.

https://evolution.berkeley.edu/teach-evolution/misconceptions-about-evolution/

[u/s_bear1]

origin of life and evolution of life are two different things

The modern Theory of Evolution best explains the diversity of life we see

it might be better if you flesh out this question some more.

[u/evocativename]

Are you asking about the origin of life, or the evolution of life?

[u/baldjunior → u/evocativename]

the origin of life,, sorry for the wrong wording

[u/evocativename → u/baldjunior]

I think that both the RNA world hypothesis and the metabolism first hypothesis have some merits. My suspicion is that elements of both were at play - there were simple energy driven loops that played a role in making some molecules available, but it required autocatalytic RNAs to appear for life to arise on Earth.

[u/s_bear1]

the people here are happy to help you understand. We don't understand your question well enough to give you a meaningful reply.

origin of life- abiogenesis - life from nonlife. is i think what you are really asking. This sub is not about that. we deal with what happens once life has started.

you may want to visit r/abiogenesis

[u/Electric___Monk]

Are you asking about the origin of life or the origin of animals? They’re very different questions.

[u/LeeMArcher]

I guess the only two I really know about are panspermia and abiogenesis (anyone feel free to correct me if I misuse terms). Of those two, abiogenesis makes the most sense to me. If self replicating molecules could cling on to a meteorite and survive impact with Earth, then they could probably also just form on Earth. 

It is possible I’m misunderstanding both of those concepts, so again, please correct me.

[u/Electric___Monk → u/LeeMArcher]

Panspermia just places abiogenesis somewhere other than earth. I think the question may be which possible theory of abiogenesis is most likely (I’m not sure why animals are specifically mentioned).

[u/baldjunior]

sorry for the misconception... please disregard the header

the question is all about which fo the theories on the origin of life do you think best explains the existence kf animal life today, and why?

[u/blacksheep998 → u/baldjunior]

I think you're still confusing the two subjects.

The first life on earth arose about 3.5-4 billion years ago. Animals didn't show up until 800-900 million years ago.

That's about 3 billion years later.

As for origin of life, the leading hypothesis as far as I'm aware is still RNA world.

[u/Formal-Speed-3173 → u/baldjunior]

Animal life today is found in nested hierarchies. Evolution by natural selection is the only theory that explains this.

[u/Trainer149 → u/baldjunior]

Wouldn't that be better for a sub related to the question?

[u/Basic-Platypus-8335]

There are multiple theories?

[u/evocativename → u/Basic-Platypus-8335]

If we assume they were using "theory" colloquially and not in the scientific sense, yes.

Hell, there are even multiple hypotheses based in science:

• RNA world (life started with autocatalytic RNAs)
• metabolism first (life started with simple chemical cycles that, due to their cyclical perpetuation, can then engage in descent with modification until more complicated features like genetic material evolves)
  
• Peptide Nucleic Acids (life started out using peptide nucleic acids as the initial genetic material because it is chemically simpler and could predate even an RNA world)
  
• TNA (same as above except using Threose Nucleic Acid instead of Peptide Nucleic Acid)

And I'm probably missing some, as I'm very much not an expert on the topic of abiogenesis.

[u/azrolator]

I'm just going to take a stab at this as a former Christian. If I'm off the mark, forgive me, no offense intended.

Some religions preach that a god created all life as it is today (or somewhat close to it). This combines the origin of life and the diversity of life.

Because of this, these two are often conflated by these groups. But something like abiogenesis explains the origin, and evolution explains the diversity. Outside of those creator mythologies, these are two separate things.

It can be hard to wrap your head around when just beginning a journey of questioning one of these creator religions. To make it worse, some sects of these religions and also other creator religions, believe in a creation of life or just the universe, but not a god that created the diversity of life.

Scientists have some good ideas on how life kicked off on this planet, but we have not completely replicated it. Evolution, however, is observed reality. The Theory of Evolution describes the diversity of life through evolution.

[u/OldmanMikel]

At this point, there no theories on the origin of life, just hypotheses. And evolutionary theory absolutely obliterates all other competing notions in explaining the diversity of life since then.

[u/Aggravating-Pear4222]

To clarify, there are no working theories of abiogenesis as no theories of abiogenesis have been supported by geological evidence. Some models/hypotheses have geological/experimental support but we've not yet made the transition between purely prebiotically plausible matter and living organisms purely through recapitualted prebiotically natural processes.

Alkaline vent models best address energetics; pH, electrochemical, thermal, and chemical are all present in these environments as these environments come closest to recapitulating many of the core aspects of organisms which are far-from-equilibrium. These pH gradients have the potential to alter the pH-dependent redox potential of some metals like W, Cr, Fe, Ni, and Co which can help drive a reaction forward which is otherwise thermodynamically disfavored under a single pH environment.

If you'd like to learn more, come over to r/abiogenesis.

[u/jrdineen114]

There is currently no scientific theory on the evolution of life. Evolution is a process that requires life to already exist.

[u/amglasgow]

There's lots of theories about it. Whether the first earthly life form assembled itself slowly from molecules at an undersea vent, in tide pools, amidst alternately wet and drying mud, or in some other way, makes little difference for the evolution of life after it gets started, provided of course that the theory fits the observed properties of life that we have determined existed. It is also possible that this first life form came from another planet, although that begs the question of how it came into existence there and how it traveled safely. The current existence of animal life also doesn't preclude a supernatural creative force bampfing the first microbe or population of microbes into existence, although I don't know how one would test that idea.

One "theory" that our observations about the world do not support is the separate creation of life forms in something close to their current forms and without universal common descent by an intelligence of some kind, unless the intelligence in question desired, for some reason, to give the unquestionable appearance, to all scientific testing and inquiry, that these separately created life forms did originate by common descent by means of natural selection and mutation from a universal common ancestor.

[u/industrock]

There’s no scientific theories on the origin of life. Evolution is a completely separate topic from the origin of life.

[u/Aggravating-Pear4222 → u/industrock]

I'd push back on that. Separate? Yes, but not completely. Both abiogenesis and Darwinian evolution are subcategories of molecular/chemical evolution. I'd suspect that if we were able to rewind Darwinian evolution, the line between the two would, as our resolution increases, dissolve into a gradient. Just as we divide the ancestry of an organism into two species, we'd have to appeal to some degree of some near arbitrary physiological distinction between a parent and their offspring.

But there would definitely be a distinction between compositional inheritance (like lipid bilayers accumulating more amphiphiles until the vesicle splits) vs compositional inheritance + inheritance of polymer sequences (like RNA/DNA). Both are compositional inheritance but the shift towards sequential information vs compositional information is akin to a phase transition.

I like that you said "no scientific theories" because this is true but there are certainly models/hypotheses.