Long thought to be among the most deterministic of animals, Ants have now been found to display infidelity...cheating. According to researchers Hughes and Boomsa, some male ant's genes are more dominant and are found in neighboring populations of ants as well as at home with momma. Hughes claims that if that were found out amongst the general male ant population, the equivalent of an ant revolt would break out against the philandering ants. So the cheaters do it on the QT, sneaking out the back way as it were. Sounds like non-determinism to me.
So what we always knew, is now wrong.
Full story is at the 3/10 issue of the Proceedings of the National Academy of Sciences.
3 comments:
So the cheaters do it on the QT, sneaking out the back way as it were. Sounds like non-determinism to me.
What? These are ants, not independent actors in a touring production of 'Les Liasons Dangereuse'. You've misread the research, Stan. Determinism (?) is not what this is about. The ant male's behavior is still stereotypically hard-wired; what you see here is the perpetuation of a variation in the 'hard-wiring' of the population such that a certain percentage of ants have post-zygotic developmental variation that increases the chances of their genes being passed on to the next generation. In other words, a typical consequence of natural selection.
So what we always knew, is now wrong.
Come again? I assure you, as a devotee of E.O. Wilson, this is not a fundamental breakthrough or a paradigm-smashing event. Here's the abstract, with a few key phrases highlighted:
Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical. All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities of the former. The most significant potential conflict in social insect colonies is over which individuals become reproductive queens rather than sterile workers. This reproductive division of labor is a defining characteristic of eusocial societies, but individual larvae will maximize their fitness by becoming queens whereas their nestmates will generally maximize fitness by forcing larvae to become workers. However, evolutionary constraints are thought to prevent cheating by removing genetic variation in caste propensity. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their nestmates by biasing their larval development toward becoming queens rather than workers. Two distinct mechanisms appear to be involved, one most probably involving a general tendency to become a larger adult and the other relating specifically to the queen–worker developmental switch. Just as evolutionary theory predicts, these "royal" genotypes are rare both in the population and within individual colonies. The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression by cooperative genotypes, the efficiency of which is frequency-dependent. The results demonstrate that cheating can be widespread in even the most cooperative of societies and illustrate that identical principles govern social evolution in highly diverse systems.
To summarize: this is a classic case of a testable prediction generated by TENS leading to exciting new findings which are (unsurprisingly) consistent with the model that inspired it. This has no bearing on the philosophical question of whether or not big complex organisms like ourselves are truly free agents. None whatsoever.
ummm, you are right Scott, in that I got it from the MSNBC news release, and I probably shouldn't comment on news releases...I don't subscribe to NAS.
However, in your excerpt, I find the following qualifications:
"evolutionary constraints are thought to..."
"mechanisms appear to be..."
"most probably..."
Then the conclusion is drawn that the theory predicted it all. Well, sure it did. Or at least it is thought to appear that it probably did.
And this:
"Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical.
Not identical? Then they have individual tastes? No, that can't be, everything is under the control of "social evolution" here, so the tastes are genetically determined. And in that case it can't be cheating, either.
All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities of the former.
Let's put this into English: Some of the guys are gonna cheat, some aren't so we say it's in the genes; and also the non-cheaters suppress the cheaters; but then there is this convolution:
"The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression (huh?) by cooperative genotypes, the efficiency of which is frequency-dependent.
This best explanation is no more than a jump to conclusion. The phrase beginning at "avoid suppression..." is so vague that it has no empirical meaning. Now is suppression the act of tweaking your next larvae to be queen-size, or is that cheating?
The results demonstrate that cheating can be widespread in even the most cooperative of societies and illustrate that identical principles govern social evolution in highly diverse systems."
But, above that it said cheating was rare and suppressed by cooperative genotypes! Or maybe that's just amongst the royal set? Maybe the commoners are trickier or more libertine, or given to genetic manipulation behind the back.
So the empirical data given proves, beyond refutation, that 'social evolution - not just gentetic - controls all sorts of behavior, because it fits all sorts of data?? Or is it that all sorts of data can be fit to the theory?
The test of this is whether it is falsifiable. What would falsify it? (Or conclusively confirm it?). I'm sure I don't know, and I don't think they do either. It appears that maybe it was past time for them to get a paper out, and so this was the result.
This turns out to be muddy and gibberish ridden. The news release was way more fun. This is just depressingly obtuse. Of course it is just the abstract.
You are right Scott, lesson learned.
At the risk of sounding like a know-it-all, the reason it sounds like it's gibberish (or, even worse, like a bunch of hedged bets) is because you're probably not familiar with the theoretical context in which this experiment occurs:
http://en.wikipedia.org/wiki/Haplodiploidy
It turns out that ants have a different reproductive system, which leads to the interesting situation that all of the high-caste females share fifty percent of the same genes. This high degree of shared fitness is what drives the apparent 'selflessness' of individual ants who forego their own reproduction to advance the survival of the queen and her offspring.
It was considering this situation that led Hamilton to propose his famous kin selection model, and it was assumed that the dominance of the high-caste females (who are all sisters) would act to 'suppress' selfish behavior. However, in this case we see that males (who do not have the same degree of relatedness to each other) will sometimes effectively defect by deliberately biasing their genetic contribution to promote the reproductive success (fitness) of their male progeny.
So one sex pursues one reproductive strategy, and the other pursues another. That's pretty much mainstream theory. The only surprise is that individual males are able to make a detectable genetic dent in the promotion of future colonies in which the hierarchy is entirely female.
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