NARROW HYBRID ZONE BETWEEN TWO SUBSPECIES OF BIG SAGEBRUSH (ARTEMISIA TRIDENTATA: ASTERACEAE). IV. RECIPROCAL TRANSPLANT EXPERIMENTS

Han Wang; E Durant McArthur; Stewart C Sanderson; John H Graham; D Carl Freeman

doi:10.1111/j.1558-5646.1997.tb02391.x

NARROW HYBRID ZONE BETWEEN TWO SUBSPECIES OF BIG SAGEBRUSH (ARTEMISIA TRIDENTATA: ASTERACEAE). IV. RECIPROCAL TRANSPLANT EXPERIMENTS

Evolution. 1997 Feb;51(1):95-102. doi: 10.1111/j.1558-5646.1997.tb02391.x.

Authors

Han Wang¹, E Durant McArthur², Stewart C Sanderson², John H Graham³, D Carl Freeman¹

Affiliations

¹ Department of Biological Sciences, Wayne State University, Detroit, Michigan, 48202.
² USDA Forest Service, Intermountain Research Station, Shrub Sciences Laboratory, 735 North 500 East, Provo, Utah, 84606.
³ Department of Biology, Berry College, Mount Berry, Georgia, 30149.

PMID: 28568779
DOI: 10.1111/j.1558-5646.1997.tb02391.x

Abstract

Does endogenous or exogenous selection stabilize the big sagebrush (Artemisia tridentata) hybrid zone? After two years of study, our reciprocal transplant experiments showed significant genotype by environment interactions for a number of fitness components, including germination, growth, and reproduction. Hybrids were the most fit within the hybrid garden. In the parental gardens, the native parental taxon was more fit than either the alien parental or hybrids. These results are consistent with the bounded hybrid superiority model, which assumes exogenous selection, but are clearly at odds with the dynamic equilibrium model, which assumes endogenous selection and universal hybrid unfitness.

Keywords: Big sagebrush; fitness; hybrid zones; reciprocal transplant experiments; selection.