“Birds fly, whales swim, cheetahs run, and amoebae ooze (not very fast)”

You have to love a scientific paper where the Introduction starts: “Birds fly, whales swim, cheetahs run, and amoebae ooze (not very fast) via cellular extension.” This paper newly out in American Naturalist comes from work that Lab postdoc Eliot Miller and Lab scientist Sarah Wagner did in Australia in their years before heading to Cornell, and it includes several other familiar names as authors:

Miller, Eliot T., Sarah K. Wagner, Luke J. Harmon, and Robert E. Ricklefs. 2017. Radiating despite a Lack of Character: Ecological Divergence among Closely Related, Morphologically Similar Honeyeaters (Aves: Meliphagidae) Co-occurring in Arid Australian Environments. American Naturalist 189. fig2

Abstract: Quantifying the relationship between form and function can inform use of morphology as a surrogate for ecology. How the strength of this relationship varies continentally can inform understanding of evolutionary radiations; for example, does the relationship break down when certain lineages invade and diversify in novel habitats? The 75 species of Australian honeyeaters (Meliphagidae) are morphologically and ecologically diverse, with species feeding on nectar, insects, fruit, and other resources. We investigated Meliphagidae ecomorphology and community structure by (1) quantifying the concordance between morphology and ecology (foraging behavior), (2) estimating rates of trait evolution in relation to the packing of ecological space, and (3) comparing phylogenetic and trait community structure across the broad environmental gradients of the continent. We found that morphology explained 37% of the variance in ecology (and 62% vice versa), and we uncovered well-known bivariate relationships among the multivariate ecomorphological data. Ecological trait diversity declined less rapidly than phylogenetic diversity along a gradient of decreasing precipitation. We employ a new method (trait fields) and extend another (phylogenetic fields) to show that while species in phylogenetically clustered, arid-environment assemblages are similar morphologically, they are as varied in foraging behavior as those from more diverse assemblages. Thus, although closely related and similar morphologically, these arid-adapted species have diverged in ecological space to a similar degree as their mesic counterparts.

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