Learn More
The role of natural hybridization in the evolutionary history of numerous species is well recognized. The impact of introgressive hybridization and hybrid speciation has been documented especially in plant and animal assemblages. However, there remain certain areas of investigation for which natural hybridization and its consequences remain under-studied(More)
The process of natural hybridization may produce genotypes that establish new evolutionary lineages. However, many authors have concluded that natural hybridization is of little evolutionary importance because hybrids, in general, are unfit relative to their progenitors. Deciding between these alternative conclusions requires that fitness be measured for(More)
Populations of the "Louisiana iris" species Iris fulva, I. hexagona, and I. nelsonii were examined genetically to test for interspecific gene flow between I. fulva and I. hexagona, for pollen- versus seed-mediated introgression between these species, and for the presumed hybrid origin of I. nelsonii. Genetic markers were identified by using both a(More)
Genetic mapping studies provide insight into the pattern and extent of genetic incompatibilities affecting hybridization between closely related species. Genetic maps of two species of Louisiana Irises, Iris fulva and I. brevicaulis, were constructed from transposon-based molecular markers segregating in reciprocal backcross (BC1) interspecific hybrids and(More)
Over the years, the evolutionary importance of natural hybridization has been a contentious issue. At one extreme is the relatively common view of hybridization as an evolutionarily unimportant process. A less common perspective, but one that has gained support over the past decade, is that of hybridization as a relatively widespread and potentially(More)
The formation of hybrid zones between nascent species is a widespread phenomenon. The evolutionary consequences of hybridization are influenced by numerous factors, including the action of natural selection on quantitative trait variation. Here we examine how the genetic basis of floral traits of two species of Louisiana Irises affects the extent of(More)
Several models of hybrid zone evolution predict the same spatial patterns of genotypic distribution whether or not structuring is due to environment-dependent or -independent selection. In this study, we tested for evidence of environment-dependent selection in an Iris fulva x Iris brevicaulis hybrid population by examining the distribution of genotypes in(More)
Chloroplast DNA (cpDNA) markers and 12 nuclear (random amplified polymorphic DNA, or RAPD) markers were used to examine the distribution of genetic variation among individuals and the genetic and ecological associations in a hybrid iris population. Plants in the population occurred at various distances from the edge of a bayou in a relatively undisturbed(More)
The role and importance of natural hybridization in the evolutionary histories of animal taxa is still debated. This results largely from a history of zoological investigations that assumed, rather than documented, a limited evolutionary role for this process. However, it is now becoming apparent that, just as for plants, the creative effects of reticulate(More)
The idea that natural hybridization has served as an important force in evolutionary and adaptive diversification has gained considerable momentum in recent years. By combining genome analyses with a highly selective field experiment, we provide evidence for adaptive trait introgression between two naturally hybridizing Louisiana Iris species,(More)