Is there empirical evidence that giraffes with longer necks have a better chance of reproducing? A better chance of obtaining food? And, if so, what is the statistical benefit per extra centimeter of neck length?
That would be science.
But evolutionists rarely test these things.
Do you know what happens when you remove a peacocks feathers? He gets just as much peahen action as any other peacock. The peahens couldn’t care less. This entire idea of tail feathers (or necks) lengthening as it confers a slight reproductive advantage is nonsense.
I have no clue how these are and would be studied and proven, as a dude that just casually reads stuff on the webs and comes to my own hair-brained ideas; it seems completely possible that the necks originally evolved for a condition that could not be observed in the current world. Hypothetically, the high leaves theory could be based on a plant/tree that has since gone extinct. How would we know? We know the earth/climate and terrain where giraffes live now has changed significantly on evolutionary time scales.
The mating example could also evolve. Using the peacock example you mention, the feathers are a result of past mating preferences and behaviors. It's possible that the current state of affairs is a preference for song/dance/etc, so the males will become good at that. If the feathers get the way and are not important for mating, they will likely go away or change in time. My point being, mating behaviors evolve too and they must change first in order for the natural selection to occur over generations and thus change the anatomy. We can't assume every species is at some resting or steady state of evolution just because we humans decided to start studying everything, I'd completely expect that some species anatomically do not represent the current state of their mating preferences and are thus are initiating a fork in their code.
I'm always reluctant to assume a particular selective pressure for every biological trait[1], but for a species that puts up a large feather train and does an elaborate dance with it to attract a mate, my prior would be really really low on that just being a coincidence. In the case of the 2008 study the parent poster linked, they got null results but it appears based on more recent research they just weren't investigating the relevant parameters, which was improved later on the field with a better understanding of peahen vision and the biomechanics of the feather shaking dance.
Agree I'm pretty reluctant too in a case as pronounced as peacocks but wanted to take the research at face value and can still find a way to devil's advocate my away around it a plausible way [to layman me] without doing any research at all
There's no reason to expect that in modern giraffes, increased neck length would lead to increased opportunities to reproduce. Or even a better chance of obtaining food. Nature is full of trade-offs. There's a balance between how much advantage you get from an extra inch of neck length and the extra calories and increased stress on the body from that extra inch.
Giraffes aren't just going to keep getting taller until they have to bend over to eat leaves.
Astute point. Similarly in pools of high level athletes you can't find correlations between sports success and certain traits that are well understood to promote performance.
It would be too expensive to maintain many generations of giraffes with less sexual selection pressure to breed the equivalent of couch potato average Joes to test, but that's what model organisms are for.
In the study reported on in the article you cite, they do no such thing. Rather, they fail to find a statistical correlation between display size and mating success.
The people doing the study, incidentally, are also 'evolutionists'.
That would be science.
But evolutionists rarely test these things.
Do you know what happens when you remove a peacocks feathers? He gets just as much peahen action as any other peacock. The peahens couldn’t care less. This entire idea of tail feathers (or necks) lengthening as it confers a slight reproductive advantage is nonsense.
https://www.abc.net.au/science/articles/2008/03/27/2200822.h...