Comments on: Does Infidelity Pay Off (For Sparrows)? http://popsych.org/does-infidelity-pay-off-for-sparrows/ The Internet's Best Evolutionary Psycholo-guy Wed, 03 Jan 2018 01:05:13 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Jesse Marczyk http://popsych.org/does-infidelity-pay-off-for-sparrows/#comment-193 Jesse Marczyk Mon, 11 Jun 2012 00:53:13 +0000 http://popsych.org/?p=346#comment-193 For the within-brood measures, the extra-pair young were proportionately and ultimately more likely to survive to the recruitment phase. Both findings could support the good genes theory (though they may also be confounded somewhat with levels of parental investment - potentially in both directions - which wasn't reported on in the current paper). Concerning the non-mixed paternity broods, they can come about through two means: (1) the females don't engage in affairs because they don't feel particularly inclined, or (2) they engage (or attempt to engage) in affairs, but fail to conceive as a result of them, and the two cases would need to be examined separately. Some broods might have escaped extra-pair offspring simply by virtue of successful mate guarding or sperm competition outcomes on the part of the resident male. I would imagine the non-mixed broods that are the outcome of the former would tend to be higher-quality than the non-mixed broods resulting from the latter path. Though the authors don't touch on the point, there are three competing possibilities, concerning these affairs: females are having affairs with higher-quality males, females are having affairs with lower-quality males, or females are having affairs randomly, with respect to quality relative to their current mate. I feel it should be obvious at this point which of the three is the most plausible. For the within-brood measures, the extra-pair young were proportionately and ultimately more likely to survive to the recruitment phase. Both findings could support the good genes theory (though they may also be confounded somewhat with levels of parental investment – potentially in both directions – which wasn’t reported on in the current paper).

Concerning the non-mixed paternity broods, they can come about through two means: (1) the females don’t engage in affairs because they don’t feel particularly inclined, or (2) they engage (or attempt to engage) in affairs, but fail to conceive as a result of them, and the two cases would need to be examined separately. Some broods might have escaped extra-pair offspring simply by virtue of successful mate guarding or sperm competition outcomes on the part of the resident male. I would imagine the non-mixed broods that are the outcome of the former would tend to be higher-quality than the non-mixed broods resulting from the latter path.

Though the authors don’t touch on the point, there are three competing possibilities, concerning these affairs: females are having affairs with higher-quality males, females are having affairs with lower-quality males, or females are having affairs randomly, with respect to quality relative to their current mate. I feel it should be obvious at this point which of the three is the most plausible.

]]> By: Ruben http://popsych.org/does-infidelity-pay-off-for-sparrows/#comment-191 Ruben Sun, 10 Jun 2012 12:49:35 +0000 http://popsych.org/?p=346#comment-191 I thought it would have been a good test of the good genes theory, hadn't it been for the strategy, which you correctly admonish to simply count the hatched grandchildren. I think it's great that they analyzed within-brood, but it'd still be interesting to see how fitness panned out for the non-mixed brood. For the within-pair broods one might think that they landed both good genes and investment and could maybe show this by counting the extrapair paternities of the male, but that introduces some circular reasoning I'm afraid. But I'd reckon the extra-pair broods can't be interpreted straightforwardly, because the male's investment may destroy the supposed good genes advantage (or not). I thought it would have been a good test of the good genes theory, hadn’t it been for the strategy, which you correctly admonish to simply count the hatched grandchildren. I think it’s great that they analyzed within-brood, but it’d still be interesting to see how fitness panned out for the non-mixed brood. For the within-pair broods one might think that they landed both good genes and investment and could maybe show this by counting the extrapair paternities of the male, but that introduces some circular reasoning I’m afraid. But I’d reckon the extra-pair broods can’t be interpreted straightforwardly, because the male’s investment may destroy the supposed good genes advantage (or not).

]]> By: Jesse Marczyk http://popsych.org/does-infidelity-pay-off-for-sparrows/#comment-187 Jesse Marczyk Sun, 10 Jun 2012 01:08:49 +0000 http://popsych.org/?p=346#comment-187 I wouldn't really know what to do for non-mixed broods; I'm not sure there's a quick or easy solution to the problem. That said, I'm not sure that counting offspring is going to be the best use of time when it comes to understanding behavior in the first place. I wouldn’t really know what to do for non-mixed broods; I’m not sure there’s a quick or easy solution to the problem. That said, I’m not sure that counting offspring is going to be the best use of time when it comes to understanding behavior in the first place.

]]> By: Ruben http://popsych.org/does-infidelity-pay-off-for-sparrows/#comment-186 Ruben Sun, 10 Jun 2012 00:03:00 +0000 http://popsych.org/?p=346#comment-186 Good rundown! What would you have done with the non mixed broods? What about statistical control for parental fitness? Good rundown! What would you have done with the non mixed broods? What about statistical control for parental fitness?

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