SIC TRANSIT GLORIA MUNDI: WHEN BAD THINGS HAPPEN TO GOOD BUGS

Origination and extinction, the Alpha and Omega of Evolution, are the principal factors shaping biological diversity through time and yet the latter is often ignored in phylogenetic studies of insects. Extinct lineages play a dramatic role in revising our concepts of genealogical relationships and the evolution of major biological phenomena. These forgotten extinct clades or grades often rewrite our understanding of biogeographic patterns, timing of episodes of diversification, correlated biological/geological events, and other macroevolutionary trends. Here I present three examples from studies of insect phylogeny, one from each of the eras in hexapod evolution, that highlight the need for a truly holistic (neontological and paleontological) perspective toward the study of insect phylogeny and evolution. From the Paleozoic, the earliest evidence for insect origins and their initial diversification is discussed in the light of recent discoveries pushing back the principal clades of Hexapoda and re-dating the timing of the rise of powered flight. From the Mesozoic, an example from termite (Isoptera) diversification emphasizes the futility of dating divergence events in the absence of integrated paleontological data (i.e., molecular-only estimates). Lastly, from the Cenozoic, the phylogeny of eusocial corbiculate bees (Hymenoptera: Apidae) has been debated for decades along with its associated implications for the numbers of origins for this complex suite of behaviors. Yet, paleontological evidence serves to brush aside many competing hypotheses and resolves a single evolutionary narrative for this group of familiar bees. In each example, the need for further integration of paleontological evidence into modern phylogenetic research on insects is emphasized.