Elbmis

  Working scribels Emergence Spandrels pre-adaptations Epiphenomena might start out as spandrels but develop into vital features. Eg. Gills might develop into food capture webs in say, barnacles, or into jaws, as in vertebrates, or into wings, as in insects. None of these were part of the original function of gills, and they might remain vitally important even after the gills totlly lose their original functions, but they piggy-backed onto the original function, at first as minor functions, or even minor impositions -- major impositions would generally cause rapid extinction -- then as vital functions, or even as barely recognisable functions while the original function vanished. Mutualistic associations with functions such as mycorrhizae and root nodules arose from counterfunctional parasitic growths that originally were irrelevant or actively harmful epiphenomena. There is a lot of mindless quibbling about what is or is not a biological spandrel as opposed to architectu...