Problems with Mutation and the Evolution of the Sexes

I think you can.Sexual reproduction is where two organisms combine forces to produce further organisms sharing a mixture of their genotypes.Sexes is where you have a system of two mating strains, with mating only between the two strains, not within strains, such that one mating strain (males) contributes a smaller gamete.It is reasonable to discuss how to get from one to the other, and I think this is Lyston's question --- at least, he seemed reasonably satisfied with my answer.

Except that it's systemic. Mutation, theory, gender, sexual/asexual, ad nauseum.As Percy pointed out upthread, it is simply not acceptable to use "gender" in a discussion of the origins of sexual reproduction.

Well, Rahvin, I am inclined to agree.It might do Lyston some good to prowl around the other threads, tho, rather than pile all his expectations into this thread.If we accomodate all his intellectual shortcomings here in this thread, then this discussion becomes the Theory-of-Evolution-Origin-of-the-Sexes-What-is-a-Mutation-What-is the-Nature-of-a-Theory-What-is-LaMarckism-thread.

Please keep the focus on the topic of discussion.

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--	Percy
	EvC Forum Director

I luled. Um, maybe you missed the whole "They had to change that" part of my paraphrase. They didn't abandon the theory that everything orbited the Earth, they CHANGED it to everything in our solar system orbits the sun. They didn't abandon the theory that everything was made of four elements, they changed it as the list grew of elements grew. They didn't abandon the theory of atoms when they discovered things inside them, they changed it to electrons (I think...?).And you said "'cos of the facts and evidence that you mentioned". You forget, they had "facts and evidence" for each of the previous theories. It was when they found out more things that they had to change them, not "abandon" them. There's actually TWO reasons I "singled out" evolution. One, the speech I paraphrased was speaking of evolution. Two, this whole forum is about EVOLUTION vs Creation. I could have "singled it out" to the theory of elemental combinations or something about psychology, but that really takes it away from the subject we are talking about.

-.- Yes the title that you changed.

I must say, after finishing all the comments since I've logged off, Rahvin is still the only one with a level head. I haven't seen someone defuse the bomb like that since Arashi Kaze on an Imeem thread.Well, as to not ruin the nicely performed job of Rahvin, let's continue my journey to discovery, shall we? This completely throws me off. You call them asexual, but also say they require host cells. Wouldn't that make them sexual? (I think this might be a harder subject because viruses, like you said, aren't fully defined as "alive"). I call it sexual reproduction because of wiki's theory #2 on origins of sexual reproduction saying that a parasite (and I'm thinking virus when I type this) invades a cell and spreads its DNA (but is actually RNA?). Maybe its not actually a virus though. Like a parasitic bacterium?I know its off topic, but do you guess think that the first organisms were simpler than bacteria, like viruses? Or was bacteria first? Can someone explain what is considered the first organism?

Can't forget "needs-to-learn-science-only-uses-the-term-sexes-not-genders."

The definitions, like the definition of a "species," are fuzzy - it's not black/white, true/false. Yes, a virus requires a host cell...but there isn't really an "exchange" of genetic information. No information from the host cell is passed on to the viral progeny - the virus basically takes over the cell's mechanisms and forces it to make more virus particles.Real sexual reproduction would involve an actual exchange of genetic material, not what amounts to a hostile takeover of a cell and turning it into a sort of biological virus factory. Real, most accurate possible answer? "We don't know." We really have no idea - all we have are "likelihoods." We also have to work at defining exactly what would be considered "life," because if abiogenesis is the origin of life on Earth (again, this is not what the Theory of Evolution says, it's just one of several possible starting points for evolution), we're going to be talking about a progression of pre-cell self-replicating strands of proteins. Are those self-replicating molecules considered alive? They'd be a lot like viruses. Do we not consider it "alive" until it forms something that better resembles a cell? Honestly, we don't know, becasue organisms this small and simple don't fossilize, so we will never find any "record" of their existence.It is likely however, from observing the forms of life currently on Earth, that the "first" life was very simple compared to the variety we see today. What we know is that it had to be self-replicating, and that its copying process must have been imperfect - those are the prerequisites for evolution to start working, and since we see evolution working today (and plenty of evidence of it working in the past), it's most likely the same was the case from the start.I would personally say that it's very likely that the first "life" existed as a very simply self-replicating molecule, something akin to RNA. Given the right environment of organic chemicals (and we know such chemicals exist in an abiotic environment from such examples as Titan), such molecules could reproduce without a cell membrane or any of the other cellular structures we see today. Imperfect replication and environmental differences could allow such molecules to do all sorts of interesting things to make something closer to what we would recognize - conjoining two of the single-helix RNA strands to make the first DNA, for example, or coopting another protein structure as the first cell membrane, etc. A real biologist would be better at speculating in this area and explaining the current model, however.I think it's pretty safe to say that anything from a few billion years ago would be simpler than what we currently define as "bacteria."

It is unlikely that viruses were among the first "organisms" on Earth. Genomic studies have only been able to track their origin back 200 million years. Life arose 3.7 billion years ago.Evidence suggests that one of the first "organisms" to have emerged was an auto catalyzing RNA. Just a moment...There is also strong evidence that these RNAs evolved.---The question of whether or not viruses are alive continues to be a point of contention.They replicate (one of the "requirements" to be considered alive) and they evolve.However, they do not auto catalyze (in order to replicate). They hijack the host cell's machinery instead.But that's a sticking point too. I think it's pretty tough to argue that viruses aren't alive. But there are plenty of folks that would argue with me.

But viral genetic info does sometimes get left behind in the host.

These are three rather different cases, and the change from creationism to evolution is a fourth. I'd be interested to discuss the subject, but it would be wildly off-topic here. Well, I see your point. And yet an argument which can be used against any branch of scientific knowledge with equal force seems to be an ineffective argument against any particular branch of science.If your point might be restated as "since science changes, how can I trust any of it?" then I would reply that by some means or other you do. You are fairly sure of the existence of cells, for example. I suppose in principle tomorrow they could turn out to be a big hoax by biologists, or we could pull our helmets off and discover we've all been living in the matrix ...Of course, some science is solider than other bits. Our knowledge of evolution ranges from the utterly solid to "We don't know, can we have ten million dollars to research that? While you wait, here is a handful of plausible guesses and some light music". To determine which bits are solid and which are not, you have to look at the particular facts that bear on the particular question.---Thought for the day:"When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together." --- Isaac Asimov

What a virus does is force its host to produce copies of the virus. The host's genes don't get passed on the the viruses produced, so the viruses produced by the hose can't be considered the offspring of the host. That's two questions. Simpler, yes. Like viruses, no.

Yes, I know. I was only trying to get you to again consider that the reason you think the title is misrepresentative of your topic is because you are rejecting correct definitions.--PercyEdited by Percy, : Grammar.

Even if you use "correct definitions", it would be "evolution of the sexes" not "sexual reproduction". If they are the same to you, can you please make the name change to "Problems with Mutation and the Evolution of the Sexes"?