title: An ordination of life histories using morphological proxies: capital vs. income breeding in insects.
abstract: Predictive classifications of life histories are essential for evolutionary ecology. While attempts to apply a single approach to all organisms may be overambitious, recent advances suggest that more narrow ordination schemes can be useful. However, these schemes mostly lack easily observable proxies of the position of a species on respective axes. It has been proposed that, in insects, the degree of capital (vs. income) breeding, reflecting the importance of adult feeding for reproduction, correlates with various ecological traits at the level of among-species comparison. We sought to prove these ideas via rigorous phylogenetic comparative analyses. We used experimentally derived life-history data for 57 species of European Geometridae (Lepidoptera), and an original phylogenetic reconstruction. The degree of capital breeding was estimated based on morphological proxies, including relative abdomen size of females. Applying Brownian-motion-based comparative analyses (with an original update to include error estimates), we demonstrated the associations between the degree of capital breeding and larval diet breadth, sexual size dimorphism, and reproductive season. Ornstein-Uhlenbeck model based phylogenetic analysis suggested a causal relationship between the degree of capital breeding and diet breadth. Our study indicates that the gradation from capital to income breeding is an informative axis to ordinate life-history strategies in flying insects which are affected by the fecundity vs. mobility trade off, with the availability of easy to record proxies contributing to its predictive power in practical contexts.
authors.affiliation: Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014, Tartu, Estonia.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Davis
authors.affiliation: Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014, Tartu, Estonia.
authors.forename: Juhan
authors.initials: J
authors.lastname: Javoiš
authors.affiliation: Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014, Tartu, Estonia.
authors.forename: Ants
authors.initials: A
authors.lastname: Kaasik
authors.affiliation: Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014, Tartu, Estonia.|Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, EE-51014, Tartu, Estonia.
authors.forename: Erki
authors.initials: E
authors.lastname: Õunap
authors.affiliation: Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014, Tartu, Estonia.
authors.forename: Toomas
authors.initials: T
authors.lastname: Tammaru
mesh_terms: D000818:Animals; D001947:Breeding; D004463:Ecology; D005260:Female; D007313:Insecta / Q000502:physiology*; D010802:Phylogeny; D012098:Reproduction; D012621:Seasons
keywords: CSR classification; Lepidoptera; capital breeding; income breeding; insect ecology; insect life history; phylogenetic comparative methods; phylogenetic generalized least squares; polyphagy; r- and K-strategies