Folks may be wondering why Darwin was so obsessed with sexual 'selection' that he devoted more chapters to it than he did to his antihistory about humans in the book entitled Descent of Man. I came across an interesting portion of Darwin's writing, which may prove insightful.

http://www.literature.org/authors/darwin-charles/the-origin-of-species-6th-edition/chapter-06.html
Quote
UTILITARIAN DOCTRINE, HOW FAR TRUE: BEAUTY, HOW ACQUIRED.

Quote
The foregoing remarks lead me to say a few words on the protest lately made by some naturalists against the utilitarian doctrine that every detail of structure has been produced for the good of its possessor. They believe that many structures have been created for the sake of beauty, to delight man or the Creator (but this latter point is beyond the scope of scientific discussion), or for the sake of mere variety, a view already discussed. Such doctrines, if true, would be absolutely fatal to my theory.


It's worth a careful read. Beauty, if it exists for its own sake, is absolutely fatal to Darwinism. Not only Darwinism, but the very foundational philosophy on which it is based! This means that no amount of tinkering or revision could salvage his "theory".

I wonder that this issue has received such little attention. I think we may profit by considering it.

Darwin, in the very next sentence, disavows the burden of proof.
Quote

I fully admit that many structures are now of no direct use to their possessors, and may never have been of any use to their progenitors; but this does not prove that they were formed solely for beauty or variety.


One has to wonder what would prove something was formed solely for beauty! Is Darwin serious? Why does he bring up the issue in the first place, let alone ramble about it for so many paragraphs if his argument is merely "you can't prove it"? Surely he must've realized that his own standard-of-proof differded from others.

I suspect he knew better. Beauty for its own sake is what we observe. He who would explain it away has the burden of proof, it seems to me. Before proceeding further, I suggest we pause so that everyone can determine for themselves where the burden of proof lies. Does it lie with those who acknowledge what they observe, or does it lie with those who wish to disregard/dismiss/ignore observations?


Dark Matter + Dark Energy = Dark Truth

"We find that such evidence demonstrates that the ID argument is dependent upon setting a scientifically unreasonable burden of proof for the theory of evolution." - Judge Jones Kitzmiller case
http://www.talkreason.org/articles/Falsify.cfm

"To Compel A Man To Furnish Funds For The Propagation Of Ideas He Disbelieves And Abhors Is Sinful And Tyrannical." - Thomas Jefferson

"And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are the gift of God? That they are not to be violated but with his wrath?" - Thomas Jefferson