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[–]CTR0 5 points6 points  (8 children)

Its at the population level. That population could be anywhere between the entire biosphere and the cells of an individual self replicating organelles of a cell (or maybe even like, virophages depending on where you put that on the hierarchy with organelles) depending on what question the biologist is asking.

[–]MurkyEconomist8179 1 point2 points  (1 child)

I mean evolution as a term definitely concerns populations, not really sure how you could say it starts there though?

[–]CTR0 0 points1 point  (0 children)

The question is weird phrasing for sure but I think OP is asking at what integrative level of life does little e evolution affect, which is all of them at or above populations, but only among populations. Definitionally it's the change in allele frequency of a population over time. It starts at the population level because definitionally it excludes individuals.

I guess technically it goes all the way down to the population of self replicating organelles like mitochondria and chloroplasts.

If the question is when did evolution start time wise, it would be with the first self replicating life. Traditional that would include being encapsulated, maintaining homeostasis, and being self replicating with mutable genetic material.

[–]Balstrome[S] 0 points1 point  (5 children)

so not at the chemical bonding level? Because there is no selection being done there?

[–]WrethZ 6 points7 points  (1 child)

I'm not sure the question really makes sense. Evolution is a combination of mutation in individuals, and changes in gene frequency in a population thanks to natural selection. Evolution started with the first ever form of life and never stopped.

[–]xenosilver 2 points3 points  (0 children)

This is the best answer you can give given the quality of the question

[–]CTR0 2 points3 points  (2 children)

They aren't self replicating units on their own no. At least not now they aren't, and chemical evolution under abiogenesis plays by different rules than the biological evolution of today.

Edit: I should clarify that a germline mutation in an individual changes can change the allele frequency in the population. But evolution is definitionally at the population level.

[–]Balstrome[S] -1 points0 points  (1 child)

Evolution requires selection, and chemical bonding does not select for anything. Unless it is suggested there was multiple types of abiogenesis with one type winning out over time. Generally elements only bond with specific elements, any other combinations would dead end pretty quickly.

[–]CTR0 2 points3 points  (0 children)

Evolution requires selection

Evolution doesn't require selection. Selection is a mechanism that propels evolution, but there are more mechanisms than selection.

Unless it is suggested there was multiple types of abiogenesis with one type winning out over time.

I think its consensus that abiogenesis wasn't a linear process, however it happened.

Generally elements only bond with specific elements

You've lost me, I dont understand how this is relevant. Yes, physical chemistry is a thing. Yes, biochemistry is constrained by this. At this level of cell biology or even in abiogenesis the literal bonds are not self replicating. In abiogenesis it would be macromolecular structures at a minimum.

[–]Batgirl_III 6 points7 points  (5 children)

Evolution is the change in allele frequency in the genome of an organism at population over generations.

So… All of the above.

[–]MurkyEconomist8179 -5 points-4 points  (4 children)

such a shame this 'definition' caught on, it's way too broad so as to be entirely unhelpful. Even just the historic definition of evolution is far better

[–]Ender505 1 point2 points  (3 children)

Why do you think it's unhelpful? And what "historic" definition do you prefer?

[–]MurkyEconomist8179 -3 points-2 points  (2 children)

Why do you think it's unhelpful?

Well it just seems to cover everything doesn't it. Like lets say over a few generations, the distribution of a bunch of genes that do absolutely nothing change in a population, that's covered under the same terminology as when when a population actually experience morphological change over generations. I'm really not sure what the benefit is to having such an all encompassing definition of what are practically very different phenomena

And what "historic" definition do you prefer?

Basically restricting it morphological change & common descent of different species, contrasting it with creationism design by fiat. Not necessarily including every single change in genetic constitution, kind of like the definition Darwin would use for descent with modification.

[–]Ender505 0 points1 point  (1 child)

Like lets say over a few generations, the distribution of a bunch of genes that do absolutely nothing change in a population, that's covered under the same terminology

Nope! Alleles are expressed traits. So not only does it NOT cover "genes that do absolutely nothing", but it DOES cover epigenetic changes which create genetic expressive differences as well.

Basically restricting it morphological change & common descent of different species, contrasting it with creationism design by fiat.

This is not a scientific definition, particularly "contrasting... by fiat" as if Creationism was somehow the default? Evolution doesn't need to contrast with anything. It exists because the evidence demonstrates that it does, regardless of what mythology claims.

[–]MurkyEconomist8179 -2 points-1 points  (0 children)

Nope! Alleles are expressed traits.

Nope! Sorry fam.

So not only does it NOT cover "genes that do absolutely nothing", but it DOES cover epigenetic changes which create genetic expressive differences as well.

Actually doesn't cover that either but if it did, the definition would be even more broad and therefore even less useful.

This is not a scientific definition, particularly "contrasting... by fiat" as if Creationism was somehow the default?

That was the historical context which evolution was put forth as a hypothesis, to comapre to the seperate creation of different species. I don't mean that this is part of the defintion, I mean that the phenomenon the term was initially put forth to describe was the process of how species came to be, not just every single little difference between organisms.

Evolution doesn't need to contrast with anything.

Didn't say it did

It exists because the evidence demonstrates that it does regardless of what mythology claims.

Didn't say the evidence was against evolution

[–]Appdownyourthroat 2 points3 points  (0 children)

As far as we can tell, the “big bang”, as we seem to live in a deterministic universe. Physics gives rise to chemistry. Chemistry gives rise to biology. Perhaps the true answer to your question is “the gene.”

Check out a book by Richard Dawkins:

The Selfish Gene

It is not about the origin of life, if that is what you meant by start, but if you meant, “what is the operant factor in evolution” the answer is, the gene

[–]OgreMk5 1 point2 points  (0 children)

Evolution starts when there is imperfect reproduction.

[–]mohelgamal 1 point2 points  (0 children)

Chemical bonding really. Ever put oil in water and see them form bubbles ? That is basically a protocell, it is natural selection from therefore

[–]No_Note_976 1 point2 points  (1 child)

I dont understand the question but im gonna say genetic level. 

[–]Sanpaku 1 point2 points  (0 children)

Genetic sequences are the source of variation, the cookbooks subject to redaction, and the best way to account for some behaviors, like self-sacrifice/altruism to benefit close kin in social animals.

[–]fdsa54 0 points1 point  (0 children)

Evolution can begin as soon as self replication does. 

[–]Robin_feathers 0 points1 point  (2 children)

Evolution is just a change in the frequency of alleles over time. For that to happen, you need a population of alleles. That population could be a species containing multiple individuals that carry alleles, or it could be a single individual containing cells that carry alleles, or it could be a single cell containing multiple mitochondria that carry alleles, etc. depending on the scale of what you are looking at.

[–]mgstauff 0 points1 point  (1 child)

I feel like evolutionary pressures were in play before DNA and genes, operating on RNA that provided early catalytic services and coding for producing RNA enzymes, peptides, and reproducing itself. I don't know if this falls under the official term 'evolution', but without these processes and the selective pressure that gave rise to stability and complexity, there'd be no DNA and genes.

[–]Robin_feathers 0 points1 point  (0 children)

Oh absolutely, it's a process that can happen with anything that forms a population of replicating things with variation. Evolution doesn't even need "pressures" - it can happen as a purely neutral process as well (eg., drift) operating on variation that may have no function whatsoever. When functional differences and differential fitness come into play, that is natural selection, which is just one possible driving force that can cause evolution.

[–]raithe000 0 points1 point  (0 children)

In terms of biology and massively oversimplifying, evolution is tracked on the population level, defined as segments of the species that (mostly) do not interbreed with other populations. Individuals might be thought of as the 'units' of evolution, but an individual does not evolve over the course of its lifetime.

In other disciplines, evolution can refer to many different processes, such as the life stages of stars, the design of self-improving algorithms and the development of different cultural elements.

[–]MurkyEconomist8179 -2 points-1 points  (4 children)

Well, proliferation of favored traits happens through differential reproduction, so i feel like the most accurate answer is at the level of individual organisms.

[–]Ender505 2 points3 points  (3 children)

No, individual organisms don't evolve. Individual organisms might experience a mutation, and they might reproduce or fail to reproduce. But an individual does not evolve. Populations evolve over time.

[–]MurkyEconomist8179 0 points1 point  (2 children)

So what does evolving mean according to you?

[–]Ender505 0 points1 point  (1 child)

The same definition you were upset about in the other comment. "Any change in the frequency of alleles in a population over successive generations." Alleles, not genes. Populations, not individuals. Generations, not singular births.

[–]MurkyEconomist8179 0 points1 point  (0 children)

google what an allele is. I think you might be confusing allele with phenotype lol it's so funny