In a nice illustration of how science works, there had been conflicting explanations for how the Giraffe evolved its long neck, but before creationists get over-excited neither of them were alternatives to evolution; the debate was about the precise drivers of evolution. That the giraffe's neck evolved from a shorter neck of a common ancestor with the related okapi was never in dispute.
One school of thought was the standard Darwinian view that it was the result of an arms race between giraffes and their preferred food plants; the other was slightly more complex, involving female sex selection and the way male giraffes use their necks against rival males with longer neck being a distinct advantage and the winner winning the favours of the females. Since the length of the neck is not strictly sex-linked, meaning it is mostly coded for by genes located on autosomes, rather than on the Y sex chromosome, both males and females benefit from this sex-selection, or so the second school of thought ran.
Now, a team of scientists led by Penn State biologists believe they have resolved this dispute buy, in the time-honoured scientific way, by examining the evidence and letting it speak for itself. What they found was that females actually have proportionately longer necks than males, so sex selection is unlikely to be the driver. However, what they observed was that females are better able to reach leaves in the crowns of trees and so get the more nutritious food, with obvious benefits for their offspring
The team have published their work, another incidental refutation of creationism that comes from revealing scientific facts, open access, in the journal Mammalian Biology. It is also explained in a Penn State University News release:
