rationalskepticism.org

Mr.Samsa wrote: For example, we'd need to figure out whether antlers developed as a result of this behavior

Physical traits can't evolve because of a behaviour.

Mr.Samsa wrote: or whether this behavior co-opted horn-like growths on the head to produce antlers.

Some initial horn like growth would start with some new genes

Mr.Samsa wrote: And even if we could figure out the two, we'd still need to establish whether the "knocking heads" behavior is something which has evolved, or whether it is a learnt behavior - i.e. just because the antlers have been selected as an adaptive trait, does not mean that the behavior has equally been selected.

Well, if it were learnt the females would have the same antlers but just not the behaviour.

Mr.Samsa wrote:

sprite wrote: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.

Interestingly, you'll note that none of this suggests that there is an innate "knocking heads" behavior, which is supposed to be the point of the example.

The point is that if only the males have antlers they have evolved because of some previous male-male behaviour where the gradual increase in the size of horn growth on the head was advantageous.
Whether this is head-knocking or scraping pretty designs in tree trunks is hardly the point. But head-knocking would seem somewhat closer to the mark being such a widespread behaviour across many species.

Mr.Samsa wrote:

sprite wrote:

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.To claim that it is is a severe misunderstanding of evolutionary and behavioral theory.

So transporting sperm to eggs is not an adaptation??????????????

How the fuck do you keep reaching these conclusions?

So you are saying that when the sex cells were the same and some became smaller and mobile this was not an adaptive advantage at the time? And the various chemicals and signalling mechanisms between eggs and sperm were not selected because they were advantageous?
And when organisms became mobile that a male better able at seeking out and perhaps mate-guarding a fertile female was not an advantageous adaptation.
You think that olfactory and visual signalling that elicit behaviours from the other are adaptive physical and chemical traits that are adaptive independently of the mating behaviour they have evolved to elicit?
And that males depositing or expelling or ejaculating sperm (perhaps rewarded with an orgasm)in the vicinity of ripe eggs is not an adaptation?

Mr.Samsa wrote:I'm using their standard usage in reference to behavior. "Biology" refers to the general bodily functions, "evolved" refers to behaviors that have specifically come about as a result of evolutionary processes, and "adaptive" refers to those behaviors which have evolved as a result of natural selection.

So which evolutionary processes other than natural selction (including, of course, sexual selection) to you consider important? Of course drift comes into it, founder effects etc. Anything else in your mind?

Mr.Samsa wrote:

sprite wrote:

Mr.Samsa wrote:

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.

And immediately before that:

In sympatric populations,
C. splendens females respond negatively against large dark wing
patches typical of C. virgo males (Figs. 2B and 3). Presumably,
these sympatric females perceived males with entirely dark wings
as being heterospecific (C. virgo) males and therefore rejected
them (Figs. 1A and 3). These results are entirely in line with our
previous study from a single sympatric population and confirms
that the dark wings function as a sexual isolation character between
these species (Svensson et al. 2007). Here we extended
this experiment and found that the same pattern of strong female
species discrimination holds true across three different C.
splendens populations that are sympatric with C. virgo (Figs. 2B
and 3).
In striking contrast to this strong sexual isolation in sympatry,
allopatric females do instead show a positive preference
for males with entirely dark wings (Figs. 2A and 3). Females
from allopatric populations respond significantly more positively
to such males than they do toward the normal (conspecific) male
phenotype which carries only a small wing patch (Figs. 1–3).

There was no overall preference for dark wings.

The colour of the wings distinguishes the two species in sympatric populations so C splendens females in sympatric populations discriminate against their own males with the larger dark patches ie that look most like C virgo
When in allopatric populations the preference for dark wings can be expressed.
The size of the black wing patches is correlated with male immunological condition because of the connection of the melanin producing enzyme with the immune system. So darker colour is preferred but the presence of C virgo males who have black wings means the females mate preference is countered by hybridization risk.
Also in sympatric populations the C splendens males with the darker wings are attacked more by C virgo males.

(There are also other features involved in mate choice including mate choices expressed by males.)

Mr.Samsa wrote:

sprite wrote:

Mr.Samsa wrote:

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'.

Indeed, and the quote you presented contradicts your interpretation - they do not suggest that this form of discrimination learning is a result of an evolved behavior.

Female mate choice is evolved behaviour.
Female preferences for particular male genitalia and stimulation from them are inherited. Sexualy selected behaviours.
If the males wore their different genitalia on their heads for the females to see then they would not have to mate before finding out what was actually there.


There are quite a few papers on this species eg:
Molecular population divergence and sexual selection on morphology in the banded demoiselle (Calopteryx splendens)
Gender Differences in Species Recognition and the Evolution of Asymmetric Sexual Isolation