Face Development in the Womb - Inside the Human Body: Creation - BBC

I have not been able to find any studies that look specifically at the genetic mechanism for nose development. I certainly do not know but I'll offer up two hypotheses. My first hypothesis is that the elongated nose is a remnant of the elongated lower face of our ancestral species, as you note in your answer. Take a look at link to this video (1:17 long, the part relevant to this answer begins at 33 seconds) of a time-lapse composite showing the develop of the human face. Our face develops as two separate halves that meet together in the middle. That's what creates the philtrum under our nose. Watch the especially carefully from the 54 second mark to 1 minute mark. Note that our nostrils are poin…

Short version The paper has nothing to do with punctuated equilibrum vs. gradualism (see also here), which was published a few years earlier. This debate is much different (but equally important, I think). The authors of the Spandrels paper criticized evolutionary biologists of taking a very narrow view of the evolutionary process. They claiming (wrongly) that evolutionary biologists believed that every single trait on an organism was an adaptation that resulted from natural selection. The trait would not be present unless it was an adaptation. The authors claimed (rightly) that traits could not be considered independently. Instead, the traits had to be considered in light of the evolu…