spandrel
UK[ˈspændrəl]US[ˈspændrəl]
n
A roughly triangular space between the curve of an arch and the surrounding rectangular molding or framework.
n
A space between two adjoining arches and the structure or molding above them.
n
(Biology, Evolutionary Theory) A phenotypic characteristic that is a byproduct of the evolution of some other characteristic, rather than a direct product of adaptive selection.
Etymology
The architectural term 'spandrel' has a journey rooted in the concept of expansion. It entered Middle English from the Anglo-French 'spaundre' or 'spaundrel', which was a diminutive form related to the Old French verb 'espandre', meaning "to spread out." This Old French term descended directly from the Latin 'expandere', composed of 'ex-' (out) and 'pandere' (to spread). The original logic connects to the idea of a space that is "spread out" or extended between structural elements like an arch and its frame. In the late 20th century, evolutionary biologists Stephen Jay Gould and Richard Lewontin co-opted the term, drawing an elegant analogy: just as an architectural spandrel is an inevitable, non-adaptive byproduct of mounting a dome on arches, certain biological traits are non-adaptive side effects of the evolution of other features, rather than direct results of natural selection.
Analysis
The word 'spandrel' is a simplex noun borrowed into English. Its spelling and form were adapted as a whole from the Old French 'espandre' (to spread out, expand), which itself derives from the Latin 'expandere' (to spread out, extend). The '-rel' suffix is a diminutive or nominalizing ending common in Old French.
Examples
The intricate mosaics filled the spandrels of the cathedral's great arches.
The architect designed decorative carvings for each spandrel in the arcade.
The evolutionary biologist argued that the human chin might be a spandrel, a simple consequence of other facial bone reductions.