Premium
HYBRID FITNESS IN THE LOUISIANA IRISES: ANALYSIS OF PARENTAL AND F 1 PERFORMANCE
Author(s) -
Burke John M.,
Carney Shanna E.,
Arnold Michael L.
Publication year - 1998
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1998.tb05136.x
Subject(s) - biology , hybrid , hybrid zone , evolutionary biology , heterosis , ecology , selection (genetic algorithm) , reciprocal , natural selection , germination , zoology , genetics , botany , genetic variation , gene , machine learning , gene flow , computer science , linguistics , philosophy
The assumption of hybrid inferiority is central to the two models most widely applied to the prediction of hybrid zone evolution. Both the tension zone and mosaic models assume that natural selection acts against hybrids regardless of the environment in which they occur. To test this assumption, we investigated components of fitness in Iris fulva, I. hexagona and their reciprocal F 1 hybrids under greenhouse conditions. The four cross types were compared on the basis of seed germination, vegetative and clonal growth, and sexual reproduction. In all cases, the hybrids performed as well as, or significantly better than, both of their parents. These results suggest that F 1 hybrids between I. fulva and I . hexagona are at least as fit as their parents. The results of this study are therefore inconsistent with the assumptions of both the tension zone and mosaic models of hybrid zone evolution.