A different hypothesis, which Haselton and Gildersleeve also find plausible, proposes that shifts in women's mate preferences across the menstrual cycle were adaptive in a now - extinct species that predated humans and are vestigial in humans — that is, like the coccyx, or tail bone, that remains at the end of the human spine, they persist in modern humans despite serving no apparent function. (sciencedaily.com)
In 2000, when scientists of the Human Genome Project presented the first rough draft of the sequence of bases, or code letters, in human DNA, the initial results appeared to confirm that the vast majority of the sequence — perhaps 97 percent of its 3.2 billion bases — had no apparent function. (scientificamerican.com)
That said, this still leaves a majority of our genome with no apparent function. (slu.edu)