Homeotic transformations suggest mechanisms for rapid evolution diversification in sex combs.

Evolutionary innovations refer to the emergence of new traits, functions, or behaviors in organisms and lineages over time. Although research has demonstrated that such innovations can arise gradually or through small steps (Chouard 2010), the mechanisms by which rapid morphological diversification takes place remain poorly understood (Bailey 2019). To explore this question, we used the evolution of sex combs, as a system (Ho 2018).

Dynamics of changes in apical cell area during sex comb rotation in .

Epithelia are highly dynamic tissues displaying various types of tissue rearrangements (Weliky and Oster, 1990; Taylor and Adler, 2008; Harris and Tepass, 2010; Lee , 2013; Firmino , 2016; Rupprecht , 2017). Here, we describe the dynamics of changes in apical cell area (ACA) in an epithelial system displaying tissue rearrangement resulting in sex comb rotation on the forelegs of male . The sex comb is a row of leg bristles which rotates during morphogenesis (Atallah, 2008; Atallah , 2009; Malagon, 2013).