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[Reelya]

Well, yeah, for example some lab had Amoebas infected with a bacteria, most died, but a few survived so the researchers nurture them. Later, they found that the ameobas partially recovered, but not completely, and they now required the presence of the bacteria in their cells to function properly.

[GavJ]

Well, yeah, for example some lab had Amoebas infected with a bacteria, most died, but a few survived so the researchers nurture them. Later, they found that the ameobas partially recovered, but not completely, and they now required the presence of the bacteria in their cells to function properly.

Well that's not really evidence of adaptive mutation - it could have been an existing feature that was selected, and stuck in a "flipped on" state by continuous chemical environment passed on through division later, or whatever.

The citrate thing in the E. Coli experiment, however, sounds like a slam dunk, since it sounds like they actually isolated the relevant genes and were much more explicitly controlled about it definitely being a mutation.

[Reelya]

Well, not really for the amoebas: exactly zero amoebas required the presence of the parasitic bacteria before, though a few could tolerate it. Not being able to live without the bacteria was a novel adaptation.

Also, they removed the nucleus of these amoebas, and replaced the nucleus of other amoebas cells with them. The new cells died, but when they added the bacteria to those cells, they recovered. So they can categorically state it's a genetic change, not chemical cell environment. This is how they were able to claim that they "required" the presence of the bacteria, and it excludes cell chemistry.

[Putnam]

Mitochondria are believed to have evolved the same way, to the level that we now have mitochondria pegged to a taxonomical group that tends to make similar symbiotic relationships with creatures.

Also, for a laugh, see the Lenski affair, in which Andrew Schlafly (the founder and proprietor of Conservapedia) disputed the E. Coli claims on the grounds that he doesn't believe them and that he "needs the data".

[GavJ]

That's impossible to say just from crude observation (i.e. not actually looking into their genes).

(edited to give only the better of my two examples:)

For example, you could imagine something like a special gut microbe that wiped out all the other gut populations competitively in somebody who consumes it, and then takes over all microbial metabolism roles. If so, that person would now be dependent on the new microbe for life (let's say, for sake of argument, it leaves behind some toxin that inhibits new microbes from thriving even if re-introduced later), whereas he'she was not beforehand. That would obviously not be an example of genetic mutation, since it also happens in a single generation.

That gut microbe could then be passed to a child via breast milk, for example. And so on,, and you would incorrectly identify it by the above logic as an evolutionary mutation adaptation.




if you were to make a clone of one of those people though, and raise it in a different surrogate that wasn't exposed, it would now be able to live without the aforementioned microbe again.

[Putnam]

That's impossible to say just from crude observation (i.e. not actually looking into their genes).

I never said anyone says it, only that it's believed. That's certainly not confidence.

[GavJ]

Was referring to the amoeba thing, not the mitochondria, sorry for not posting the quote at the top.
(with breast milk being replaced with "contamination of cytoplasm full of said bacteria and/or byproducts or toxins or who knows during cell division" as a non-genetic possible mechanism of heredity of the dependence)

[Putnam]

Was referring to the amoeba thing, not the mitochondria, sorry for not posting the quote at the top.

i regret nothing

[Reelya]

That gut microbe could then be passed to a child via breast milk, for example. And so on,, and you would incorrectly identify it by the above logic as an evolutionary mutation adaptation.

that's a flawed analogy. Because we need gut microbes now. So if its one lot of microbes or another you can't prove anything. These bacteria we're talking about didn't "replace" anything, thus making your entire example void.

They took Amoebas that did not require any symbiotic bacteria in the first place, and created a strain which required the presence of the bacteria.

They could tell this by removing the cell nucleus from the "new" amoebas: put them in an uncontaminated cell, the cell dies. If they did not have adaptations, they should have survived this step. Then, transplant the bacteria - which was previously an unwanted invader, into the "new" cell, and it bursts back to life. This bacteria still kills regular amoebas that haven't been exposed, but you replace their nucleus with the "new" type cell nucleus and they survive. So, whatever allows the amoeba to survive the presence of the bacteria is determined to be in the nucleus, hence genetic.

It's not a case of "well it could be bacteria A or bacteria B, what's the difference?" as in the "gut microbes" story, because there was NO "bacteria A" to start with.

[Neonivek]

Ever thought that the Amoeba took something from that bacteria?

For example our organelles are required for our cells... and many of them are other organisms, at least in design.

As well "we need gut microbes" can easily be explained by us losing a useless function (the gut microbes do it for us)

[GavJ]

These bacteria we're talking about didn't "replace" anything

And you know that... how?

Sure, they didn't replace another whole population of bacteria.  That's not the same as saying "They didn't replace anything"

The amoeba could have any number of functions that were physically or chemically inhibited, shut down, or flat out destroyed and replaced by the bacteria or byproducts of the bacteria in a way that is too slow or difficult or impossible to reverse when the bacteria are gone, leading to death before any recovery is possible, without genes necessarily being involved at all.

I'm not saying it's impossible to find out, either. It's a question that has an answer, and further scientific inquiry could resolve those ambiguities, but from what you've told me so far, I don't know that the necessary further investigation has been done yet.

They could tell this by removing the cell nucleus from the "new" amoebas: put them in an uncontaminated cell, the cell dies.

Cell nuclei can carry toxins and bacterial RNA and such inside of them, potentially. You don't know that the new cells weren't contaminated.

[Samarkand]

These bacteria we're talking about didn't "replace" anything

And you know that... how?

Sure, they didn't replace another whole population of bacteria.  That's not the same as saying "They didn't replace anything"

The amoeba could have any number of functions that were physically or chemically inhibited, shut down, or flat out destroyed and replaced by the bacteria or byproducts of the bacteria in a way that is too slow or difficult or impossible to reverse when the bacteria are gone, leading to death before any recovery is possible, without genes necessarily being involved at all.

I'm not saying it's impossible to find out, either. It's a question that has an answer, and further scientific inquiry could resolve those ambiguities, but from what you've told me so far, I don't know that the necessary further investigation has been done yet.

They could tell this by removing the cell nucleus from the "new" amoebas: put them in an uncontaminated cell, the cell dies.

Cell nuclei can carry toxins and bacterial RNA and such inside of them, potentially. You don't know that the new cells weren't contaminated.

This is an interesting, if somewhat unlikely, explanation for this phenomena. Few bacteria rely on excreting RNA, that's mostly a viral thing. On top of this, RNA is not terribly long-lived in vivo. Maintenance of RNA usually requires regular transcription inside of the cell. For this reason the RNA would likely be degraded in the new amoeba before they would die out completely. And as far as I know there is no evidence for reverse transcription occurring from bacterial DNA. Can't speak to toxins, gene regulation is more my thing.

[Tiruin]

O__O

Erm, could we segue back into a more related kind of imagery regarding the topic at hand? I got particularly lost when we began discussing microorganisms
^{And my studies on them ._. It seems like we're using it as a general analogy in the most recent posts. Which could be fallacious in that a small part missed on these tiny creatures are that they need a desired environment to live and thrive...less so causing the harmful effects towards the human body and stuff.}
By which I mean, some of the analogies present would be too general (and probably silly but its for giving ideas and whatnot anyway) if we use general terms of microorganisms to represent an idea.

...Unless that is part of the topic.

Edit: Oh hey new page. 

[GavJ]

This is an interesting, if somewhat unlikely, explanation for this phenomena. Few bacteria rely on excreting RNA, that's mostly a viral thing. On top of this, RNA is not terribly long-lived in vivo. Maintenance of RNA usually requires regular transcription inside of the cell. For this reason the RNA would likely be degraded in the new amoeba before they would die out completely. And as far as I know there is no evidence for reverse transcription occurring from bacterial DNA. Can't speak to toxins, gene regulation is more my thing.

Well toxins seemed more likely anyway. Example: bacteria releases one small mobile toxin that can pass into the nucleas and hang out. This toxin inhibits, let's say, sodium channels in the cell membrane. Bacteria also emits some protein or whatever that inhibits that toxin and allows sodium channels to work anyway (quite reasonable. After all, it may need to do this just to protect its own sodium pumps from its own waste product toxins!!), but it's too big to get into the nucleus.  Thus, when nucleus is transplanted, the toxin that hitched a ride migrates back out in a little while, shuts down the sodium pumps, nothing is there to stop it anymore, new amoeba dies.

Erm, could we segue back into a more related kind of imagery regarding the topic at hand?

Sorry, I brought it up as a complete derail, because it comes up in creationism debates and one of the comments reminded me that I was never able to cite explicit evidence.  But now that you (sort of) mention it or lead me there, it is a pretty interesting topic incidentally to ask "What do sexual versus asexual micro organisms have to teach us about gender roles, if anything?"

[Flarp]

Well, I have no idea how the thread ended up talking about mitochondria, but I'm gonna try and answer the original question.

Needless to say, gender roles are culturally-bound, relative, etc. Various disclaimers about how my views are not indicative or representative of the majority's views, or reality.

I'm a guy who likes guys. Femininity doesn't hold much appeal for me, on basically any level. Moreover, femininity, as a concept, seems to be fairly consistently built around the aesthetics that men find attractive on women, not what women actually want to look like - a completely spurious claim that I can't really back up, aside from the fact that traditional femininity has existed basically since the days of Ur, and women had very little ability to influence it (or any other aspect of culture, really) for most of the intervening time.

Aesthetically speaking, since I'm not sure how else you could deal with gender roles, I argue it would be a fundamentally good idea - but obviously a totally impossible one - to abolish femininity as a concept, because if nothing else, many peoples' personal ideas of femininity seem to include aspects of oppression of women's sociopolitical freedom (the whole "stay in the kitchen" is an extreme and oft-parodied example, but you can't deny that a lot of people still view politics, engineering, and business as "improper" careers for a womanly woman).

I can feel the Benadryl starting to kick in, so no guarantees the rest of this will make sense, but:

How implausible would it be to enforce masculinity as the appealing aesthetic on both biological genders? Obviously, for people currently attracted to women/femininity, this is probably kind of undesirable, but the internet has already shown its infatuation with capital-A Awesome, best exemplified in a certain shirtless Australian businessman. What if we just simplified everything and made Awesome - which is practically synonymous with a lot of people's ideas of "manliness" - the platonic ideal of sexiness?