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Civil discussion and debate on real world events and issues.


Red Queen's Hypothesis

   
Y'know... WE are eukarya- and many species can reproduce asexually if conditions are right.

I assume you're referring specifically to parthenogenesis. As all other forms of asexual reproduction are pretty much some form of "cloning" or another, with (unless there's a serious flaw in the process) identical DNA to their parent. Cloning's easy. Everything except a virus uses some method of cloning cells. Even some parthenogenesis is still cloning (uses a "fake" sperm cell that will have no influence over the offspring's DNA- it's pretty well identical to mommy). And THAT is weird enough unto itself- since you'd already need to have evolved to the point where you lost the "hermaphrodite" ability to NEED this variant, meaning something lost and re-invented cloning. That doesn't seem too right, either, but hey, if it happened, it would certainly spread to offspring.


The problem, even with parthenogenisis, is thus: first you have one cell. Then it becomes two cells. Then it becomes four "half cells", aka "sex cell" aka "gametes". Then these cells recombine into a new, slightly different, genetic code. That's a lot of things that have to happen where any single failure at any step means the destruction of the new would-be life form and the cessation of that biological process. Because, until it works, it's a mutation that serves no purpose- and takes up considerable organic resources. The recombination process alone is something that only bacterium can perform under anything less than "perfect" scenarios.

Promoting random uncontrolled mutations in a living creature happens sometimes. The common name for it is cancer. So these new parthenogenically born organisms would have to exist with the intent to be a new separate entity. A new form of non-cloning reproduction. But since cloning reproduction would already exist (clearly, if cloning didn't occur, we wouldn't be having this conversation).

Now once we have parthenogenic life- making the rest of the journey isn't so surprising... self fertilization externally leads to spawning, then that leads to "seahorse" carrying the young methods, then that leads to ever increasingly advanced wombs, and there you have it. By getting rid of the clone method you just sped up evolution by tens of thousands of times over regardless. But we're still facing the "deliberate recombination of cellular material" jump. The part from "can't have sex" to "can and will" have sex.

Quote:
Originally Posted by TanaNari View Post
Promoting random uncontrolled mutations in a living creature happens sometimes. The common name for it is cancer.
No, cancer is what happens when cell differentiation breaks down. The DNA need not mutate. The mechanism can break down because of chemicals or viruses.

Quote:
Originally Posted by TanaNari View Post
Now once we have parthenogenic life- making the rest of the journey isn't so surprising. By getting rid of the clone method you just sped up evolution by tens of thousands of times over regardless. But we're still facing the "deliberate recombination of cellular material" jump.
But sexually reproduction is not likely evolve from parthenogenic life. As I said before, it would evolve in single-cell organisms that later evolved to multi-cell.

Quote:
Originally Posted by Tana
I assume you're referring specifically to parthenogenisis.
No. I was referring to the fact that there are large numbers of eukaryotic species that reproduce through both asexual and sexual means. Virtually all fungi, but the buck doesn't stop there. If you're looking for a specific example, see Saccharomyces.

I will ignore your description of parthenogenesis, because it has nothing to do with the conversation of whether or not sexual reproduction can arise from an asexually reproducing population.

Quote:
Originally Posted by Tana
Promoting random uncontrolled mutations in a living creature happens sometimes. The common name for it is cancer.
Well, we weren't talking about uncontrolled mutations. But since you brought it up, no, that's not what cancer is. Cancer is the term given to various diseases characterized by dysregulated cell growth and division. Certain mutations tend to be necessary for the development of cancer. Typically, in the development of cancer, large numbers of mutations occur. But "uncontrolled mutation" is only called "uncontrolled mutation," and is typically met with apoptosis or necrosis, depending on the situation.

Quote:
Originally Posted by Tana
But we're still facing the "deliberate recombination of cellular material" jump.
Nothing about this is deliberate. And recombination of genetic material certainly doesn't require sexual reproduction. Asexually-reproducing bacteria recombine their DNA via conjugation-- and it occurs frequently in homologous sequences of DNA in virtually every variety of cell observed. Recombination is merely a physical property of the DNA molecule.

You're muddling your biological processes, throwing out parthenogenesis and recombination in the discussion when they weren't being discussed. I do believe, good sir, that you are not very biologically knowledgeable. But you know some hotwords that you've been lead you to believe are important for debating evolution. I recommend picking up a genetics text before you continue trying to fight people on this.

Well, if it's a virus, it's probably a genetic alteration. And I didn't say ALL cancer worked that way. Just that when it happens, that's pretty much what occurs.

And single cell organisms CAN NOT reproduce sexually. Certainly a good number can "have sex" in the sense of exchanging DNA from one life to another.

But this doesn't cause reproduction. In fact, it delays it. Given the rate at which bacteria replicate, it's probably the single greatest factor inhibiting bacterial growth (aside being eaten by each other).

No, the steps would be 1- Drop sex. 2- Become multicellular (as opposed to colony). 3- re-invent sex.

Quote:
Originally Posted by Tana
And single cell organisms CAN NOT reproduce sexually. Certainly a good number can "have sex" in the sense of exchanging DNA from one life to another.
Oh, there's one of your problems. You don't understand what sexual reproduction is. You seem to think that it has something to do with a binary sexual species on a multicellular level.

TanaNari, please explain your logic?
premise: I do not understand how it could have happened
conclusion: It cannot have happened.

I see a flaw there.

While I find the discussion interesting, I don't think that's the real issue here. I doubt you are a specialist in the field, and you would have to be one to give your arguments any credibility in such a specialised topic.

I'm gonna pretend I understand what the heck the OP is talking about.

So um... Red queen is a noob? Crap.

I think this article is more interesting.




 

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