+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Rensch's rule crosses the line: convergent allometry of sexual size dimorphism in hummingbirds and flower mites

, : Rensch's rule crosses the line: convergent allometry of sexual size dimorphism in hummingbirds and flower mites. American Naturalist 156(5): 495-510

Hummingbirds demonstrate the full scope of Rensch's rule (females larger than males in small species, males larger than females in large species). The phoretic flower mites that hummingbirds compete with for nectar show the same pattern. An analysis of phylogenetically independent contrasts for 154 hummingbird and 37 mite species confirmed that both small (female-larger) and large (male-larger) species contribute to this result. I propose a common cause for this convergent pattern of sexual size dimorphism, with support from ecological and behavioral data for both groups. When morphology or behavior constrains each species to a limited range of resource densities, natural selection tends to diversify body size among species. If mating is promiscuous or polygynous, sexual selection favors larger males when resources are sufficient. But if male reproductive behavior is energetically costly, smaller males may have an advantage when resources are limiting, producing a pattern of allometry for sexual size dimorphism that conforms with Rensch's rule. Stabilizing selection on female size, if it occurs, amplifies this pattern. When the resource-density spectrum is broad enough, both female-larger and male-larger size dimorphism should occur within the same clade.


DOI: 10.1086/303406

Other references

Lai, D.; Yang, X., 2014: BMP4 is a novel transcriptional target and mediator of mammary cell migration downstream of the Hippo pathway component TAZ. Since the metastatic progression of cancers is often fatal with limited treatment options, understanding the mechanism of metastasis is imperative for designing novel and targeted therapies. TAZ has been identified as a novel oncogene in both brea...

Anan'eva, NB., 1972: New data on the distribution of two species of lizard in Kazakhstan. Izvestiya Akad Nauk Kazakh SSR (Biol): 1: 50-52

Ewan, P.W.; Clark, A.T., 2005: Efficacy of a management plan based on severity assessment in longitudinal and case-controlled studies of 747 children with nut allergy: proposal for good practice. Background: There are few data on the long-term management of children with peanut/nut allergy. Advice is variable and often inadequate; further reactions are common. There is no consensus on the criteria for prescription of rescue medication, par...

Foerch, C.; Kessler, K.R.; Sitzer, M., 2003: Cerebrovascular stroke caused by paradoxical embolism during long-distance flights. History and admission findings: Over the period of one year three long-distance airline passengers (aged 21, 63, and 64 years) were admitted to our department because of a first-time acute neurological deficit having occurred during their long-dis...

Stephens, G., 1987: The effective use of ORNAC recommended standards. Canadian Operating Room Nursing Journal 5(3): 22-26

Hanlin, R.T., 1978: Revision of the Index of Plant Diseases in the United States - a feasibility study. Results are presented of a study to determine the feasibility of updating the index [RAM 40: 511] and to investigate methods of compiling and handling the data collected. An updated index for maize was compiled as a model for the possible revision...

Chen, B.A.; Creinin, M.D., 2007: Contemporary management of early pregnancy failure. Early pregnancy failure is a common pregnancy complication. This paper reviews the terminology, diagnosis, and treatment of early pregnancy failure. Although surgical curettage has been the standard of care for more than 50 years, additional treat...

Seiner, M.; Klein, E.; Klein, G., 1975: Antinuclear reactivity of sera in patients with leukemia and other neoplastic diseases. Clinical Immunology and Immunopathology 4(3): 374-381

Monk, R.W.; Wiebe, H.H., 1960: Growth and survival of some ornamental plants on salinized soils and substrates and the resistance of their protoplasm as related to salt tolerance. A comparison was made of 2 methods of testing the resistance of plant tissues to salt. These were the plasmolytic method and a new 2, 3, 5-triphenyl tetrazolium chloride method. Both were equally reliable but the TTC method was easier to apply and...

Stelmach P.; Wait J.L., 1990: Ultrasound measurement of human diaphragmatic thickness in relationship to transdiaphragmatic pressure. Clinical Research 38(1): 20A