Posted: Mar 23, 2011 9:18 am
Mr.Samsa wrote:sprite wrote:So to go back to the antler analogy, while the differences in the existence/physical structure of the antlers will affect the behaviour of the sexes, these behavioural differences would then be a product of learning? The females don't compete for males because they don't have antlers and learn that they don't so don't try to fight. The males learn they have antlers and that they can use them in competition with other males. Ummm....
Or we could say that the ancestor had males that competed by knocking heads. Some genetic variation occurred where some individuals developed hard growths on the head. This would initially have occurred in both sexes. Sexual selection and the action of establshed mechanisms to sexually limit the expression of genes that are adaptive in one sex but not the other leads to gradual increase over time of the evolution of the male antlers and the absence in the female.
I.e the behaviour of male-male competition shaped the selection of the genes for antlers in males while females did not have the same behaviour so the antler development was selected against.
Indeed - so we would have two equally plausible hypotheses. We would need to test them to figure out which is which.
You really think we need to test whether male deer evolved antlers and then started using them in competition with males? Why did they not continue to develop in females if they had no costs? And this would, of course, be going back to the first ancestor where the antlers evolved, not the current species where the sex-limited mecahnisms are already in force.
You think only male deer ancestor evolved the antlers first from the start and then it was case of 'uh, what shall I do with these?'
A lot of resources go into building antlers.
The novel trait would have been in both sexes to start with.
It would have been selected against in both sexes if it had no advantage to either.
It was selected against in females.
It was selected for in males.
It was therefore connected to the differences in behaviour of the two sexes that were there at the start.
The antlers are regrown for each mating/rutting season - again, clearly connected to male-male competition.
In caribou both sexes have antlers though the males have theirs for the rutting season and the females have theirs for the winter.
They were selected for in males due to their advantage in male-male competition, something which existed before the antlers evolved.
They were not selected against in females - or they may have been in the ancestor but again appeared in the caribou female and were then selected for in the females but with a quite different ontology than in the male, again no doubt connected to sex-limitation mechanisms - the female advantage was experienced in the winter months in competition with males over food.
Mr.Samsa wrote:The orgasm is not a behavior, so even if you could find evidence that the evolutionary path of the orgasm was different and that adaptations produced changes in males and females, this does not show that the behavior preceding the orgasm (the behavior that is rewarded) is an adaptation.
To claim that it is is a severe misunderstanding of evolutionary and behavioral theory.
So transporting sperm to eggs is not an adaptation??????????????
When eggs and sperm evolved from a one-size sex cell with one becoming large and full of cytoplasm, organelles, nutritients etc and the other reduced to just the DNA plus mobility to find the egg, these were achieved by selection and adaptive advantage. The adaptive advantage of being either one or the other but not in between. The traits that were successively selected by which sperm, or the bodies producing them, out-reproduced others of the same (males), and those successively selected by which eggs, and the bodies that produced them, out-reproduced others of the same (females) (and plays a large part in the diversity of species).
I've never come across anything but adaptive explanations for this in all the literature on the subject.
Mr.Samsa wrote:sprite wrote:What you really mean is how do we distinguish between behaviours due to interactions between adaptations and the environment and behaviours due to interactions between non-adaptive biology and the environment.
Normally this is just asked in the form of 'how do we know if this is an adaptation or not'.
That was my original question but given your failure to answer it or even support it, I had to simplify the question for you.
From a search of this thread this is the first time you have never used the words 'adaptive' or 'adaptation' so
We have this rather obscure nature of your use of 'biology' and 'evolved' which is far from clear and 'adaptation' is never used.
Mr.Samsa wrote:sprite wrote:So the female damselflies do not have a mating adaptation regarding what the male looks like in terms of the dark colour of the wings in these two species. There is also female preference for darker wings but the darkest wings belong to the other species.
So what do we actually have going on here with this 'learning'? We have a damselfly female with a mating preference for darker wings. If she is just with her own males, no problem. But when in an area with another species that is externally much the same as her own she mates with them too. Then his genitals do not match her evolved preference in her species. She can now distinguish between her own and the other species.
There was no overall preference for darker wings - the preference changed depending on their learning histories.
No. From the paper:
This suggests that the allopatric C. splendens females perceived these conspecific males with enlarged wing patches as extra attractive mates............
The strong positive female responses in allopatry suggest that female preferences are open-ended in favor of an exaggerated version of the basic male signaling trait in C. splendens, that is, the dark wing patch. Sexual selection will not conflict with
species recognition in these allopatric populations, because of the absence of heterospecific C. virgo males. Allopatric C. splendens females can and do thus show an increased preference for large dark wing patches, because they do not run any risk of mating with a heterospecific males. Although one might expect a conflict between species recognition and sexual selection in sympatry (Fig. 2B), such a conflict would not exist in allopatry at all, because there are no C. virgo males. This is the most likely explanation for the open-ended preferences in allopatry in which females clearly preferred males with entirely melanized wings.
Mr.Samsa wrote:sprite wrote:Yes, she has learned which is the correct mate but only because her evolved preference applies to the genitals and only through mating can this be known. Genitals that have evolved through sexual selection. Genitals that evolve rapidly through sexual selection and that lead to speciation too.
She has evolved to accept males with the correct genitalia and genital stimulation.
You might think that because 'learning' is involved that mate choice is not an evolved, adaptive behaviour in this species. But of course it is. It's just that the evolved adaptation concerns the genitals with copulation needing to be in progress for female choice to act.
Here we have something which on the surface looks like 'learning' but these species have always and still are making mate choices through evolved preferences for particular male genitalia.
Insane reinterpretation of the data... You're completely misunderstanding what learning and behavioral adaptations are.
Really??????????
Again from the paper:
The mechanisms for such aversive learning are still unknown, but they might have their origin in the physical interactions the males during the cage exposure experiments. For instance, heterospecific males might clasp females differently than conspecific males, or there might be a poor mechanical fit between the genitalia of males and females in the heterospecific couples (McPeek et al. 2008). Slight interspecific differences in fine-scale genital morphology (McPeek et al. 2008), might be perceived as tactical cues by females. There might also be behavioral differences between the species in how the different male types interacted with the females. These factors could provide the negative feedbacks that shape the final mate preferences in females, and the result might be an increased aversion against heterospecific males in sympatry.
So the very extensive and widely documented incredibly diverse genitalia in insects - when the bodies are otherwise indistinguishable - and the connection between this and the females choice of the sperm used, and between this and speciation etc etc plus this clearly happening here is to your mind 'insane'.
