Dynamic interplay between niche variation and flight adaptability drove a hundred million years' dispersion in iconic lacewings.

The form and change of animal biogeography reflects the long-term interplay between organisms and their environment, involving physiological limitation, dispersal capability, and adaptive evolution versus plate tectonics, global climatic shifts, and changing landscapes. This is especially manifest for lineages with extended geological histories, which, therefore, evokes questions as to the associated processes producing such patterns. Insects, as the earliest flying animals, have exceptional abilities for expanding their range and habitats and to avoid detrimental conditions. They are ideal for exploring historical biogeography augmented via adaptation. Here, we employ beaded lacewings as a model to explore such patterns and likely processes, particularly given that they differ notably from the commonly observed pattern of a latitudinal diversity gradient. Furthermore, owing to their good fossil record it can be observed that their distributions varied remarkably through time. Ecological niche modeling and evaluation demonstrate their niche variation and niche breadth expansion intermittently accompanying global climate change. However, different niche relevant variables changed under patterns of either phylogenetic conservatism or evolutionary lability. By assessing wing morphological disparity and modeling flight aerodynamics, we uncovered a continuous improvement of flight efficiency through beaded-lacewing history as well as a Paleogene divergence in strategy, which reveals a long-term associated path with the niche variation. Our results unveil the adaptive evolution and dispersal history of beaded lacewings through 170 My, achieved by dynamic strategies in niche shift and flight adaptation as responses to a changing planet.