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[Neonivek]

Well technically Reelya sexual reproduction is a lot more inefficient and a lot more prone to mistakes then asexual reproduction.

Much more often are you going to create inferior candidates for reproduction from what were stellar ones.

[Reelya]

If they were that stellar, and closely enough related to breed, they should have almost the same genome <_< making that very unlikely.

Recombination is a really efficient way of maintaining data persistency: it's like a RAID array for genomes. Even if every member of the population is heavily mutated, it only takes a few generations to regenerate "ideal" organisms that are at or near the optimal genome.

Muller's Ratchet has been shown to heavily degrade asexual species in the lab. So this idea that they "should" be more persistent doesn't actually work. Asexual species suffer much more from genetic drift in other words. Which pushes them consistently AWAY from the most efficient genome for their niche.

Well technically Reelya sexual reproduction is a lot more inefficient and a lot more prone to mistakes then asexual reproduction.

Much more often are you going to create inferior candidates for reproduction from what were stellar ones.

You forgot about the benefits of paired genes, that redundancy makes it harder for a single gene loss to cause catastrophic failure. Plus, diploid organisms use copy/repair to copy lost good genes onto damaged chromosomes. Back-up copies, in other words. That's something asexual species can't do.

[Neonivek]

That is for another reason Reelya, and that is sexual attraction.

[Reelya]

No, that's just how evolution works. -_-

A population that breeds together converges on an "ideal" genome. You only get significant drift away from that if the groups are separated and do not interbreed often. It's why all humans have 99.999999% identical genes to all other humans.

Well, look up Mullers Rachet. Pure asexual species just don't work according to the theory and labwork. only some form of stealing genes from other organisms even makes them viable. This idea you brought up how asexual organisms have this low rate of genetic defects is plain wrong and at odds with all the research.

[Neonivek]

No, that's just how evolution works. -_-

A population that breeds together converges on an "ideal" genome. You only get significant drift away from that if the groups are separated and do not interbreed often. It's why all humans have 99.999999% identical genes to all other humans.

That is actually because of how genomes work...

.000000000000000001% of a change can just create a pile of mush.

Well ok not REALLY because the genome isn't that large... but still

[Reelya]

What are you even arguing now? I'm just not following how this backs up your idea about sexual vs asexual. show me citations.

The research states that asexual species CANNOT even maintain any form of genetic purity.

Sexual reproduction can recreate the "ideal" form even if all members of the population have copy errors. It would take thousands of years for asexual reproducing entities to re-mutate all the copy-errors they accumulate back to the proper genes. This is something sexual populations can reliable do in a few generations, without needing further mutations.

[Neonivek]

What are you even arguing now? I'm just not following how this backs up your idea about sexual vs asexual. show me citations.

The fittest Reelya, not the strongest.

[Lyeos]

What are you even arguing now? I'm just not following how this backs up your idea about sexual vs asexual. show me citations.

The fittest Reelya, not the strongest.

You're... Literally making no sense, now.
Not trying to be rude, but since I've been watching this thread for a bit...
What you're saying doesn't make much sense. Sorry.

[Reelya]

Neonivek is on drugs it's official.

[GavJ]

Well technically Reelya sexual reproduction is a lot more inefficient and a lot more prone to mistakes then asexual reproduction.

Much more often are you going to create inferior candidates for reproduction from what were stellar ones.

This is evidently false simply from the large number of counterexamples in existence. I.e. ff that were true, then why did anything ever evolve to stop being asexual? It's one thing to say "Oh well, XYZ might be more adaptive, but we just didn't happen to end up with it." But it's quite another to claim "We already HAD the better thing, and then stopped doing it, on a massive scale" That should pretty much never happen in evolution.

Sexual reproduction has a large number of different mechanisms in place to protect the proliferation of the stellar genes if/when they are found.  For example, alpha males fighting each other and the winner being the stud for an entire community of individuals in species like elephant seals.

And as mentioned above, sexual attraction does this as well. Which may sometimes overlap but not always with fighting methods.



Another point to keep in mind is that there IS no such thing as an always and objectively "best" set of genes. You might think "oh that's a really good specimen. ALL of them should be like that" and for the time being, maybe it is the best. But then 10 years later, some new disease pops up, that your "best" specimen turns out to be really weak against, and BAM. All your d00ds are dead all at once. Game over.

(^This is the most glaring and dangerous aspect of big business GMO crops, for example. Not potential danger to your body, but susceptibility to new blights that can wipe out half a country's homogenous food crops. They're extremely fragile compared to natural variety, and several exploited African nations are finding out how true this is already)

Whereas the mix and mash and minced up gene pools of a sexual species may not have full proliferation of the best of the best at all times, but they will be BIASED heavily toward better genes (due to the sexual attraction etc.) and the remaining variability of the rest of them also protects the species by acting as a "gene bank" that provides for unknown future contingencies.

[Neonivek]

Because GavJ everything has a cost.

Sexual reproduction isn't a magic bullet. It actually came at a cost.

Efficiency is not sexual reproduction's advantage.

[GavJ]

I don't disagreeing with you Neonivek in what you just said.

I was arguing why the quoted statement "Asexual is more efficient and less mistakes" is wrong. Saying so does not imply the opposite. I am not claim sexual is always better instead. Only giving counterexamples to the quote.

For MANY situations (not all) and species, sexual reproduction is less error prone and more efficient, as evidenced by the fact that many (not all) species evolved explicitly away from asexual into sexual reproduction. There should be nearly zero examples of any species having done that, if sexual reproduction was less efficient across the board.

[Reelya]

http://en.wikipedia.org/wiki/Muller%27s_ratchet

In evolutionary genetics, Muller's ratchet (named after Hermann Joseph Muller, by analogy with a ratchet effect) is the process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner.

Basically there are many ways to get a bad mutation, but for each bad mutation there's only one possible mutation that "fixes" the problem. Say each base-pair has a 1/10000 mutation rate, and you have 1 million base pairs. Now, *each* offspring of that asexual organism will get on average 100 mutations: there will be no perfect copy, because that is, while not theoretically impossible, less likely than 1 over the number of atoms in the whole planet. So it's practically impossible.

The asexual organism can only "fix" these gene problems by re-mutating the good gene it lost. Since further mutations are always more likely to harm than help, the best they can hope for is to hover around the point where having any worse of a genome will kill the organism: an equilibrium point where each mutation will either make you a little better or kill you outright. That's because you've only got mutations as the mechanism to fix the problems from your last round of mutations.

On the other hand, sexual species still get the mutations: but they have a different mechanism for repairing the damage. Rather than blindly requiring massively unlikely re-mutations of genes that were already developed, they use parallelization to restore good copies of genes. Since its very unlikely that two organisms got negative mutations in exactly the same place, by recombining two genomes and having lots of progeny, that increases the chance of having offspring that maintain a full set of the best genes. Sexual reproduction actually optimizes the gene pool towards the "ideal" form. So it outcompetes the asexual mechanism which is more like "don't become so crappy that further mutations kill you outright".

[GavJ]

Have they ever actually observed any adaptive mutations happening in the laboratory yet and becoming established, by the way?

[Putnam]

Have they ever actually observed any adaptive mutations happening in the laboratory yet and becoming established, by the way?

http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment