Natural hybridization: how low can you go and still be important?

This paper examines two assumptions that have formed the basis for much of the past and present work on hybrid zones. These assumptions derive from the observation that crosses between genetically divergent individuals (e.g., from different subspecies, species, etc.) often give rise to genotypes tha...

Full description

Saved in:
Bibliographic Details
Published in:Ecology (Durham) 1999-03, Vol.80 (2), p.371-381
Main Authors: Arnold, Michael L., Bulger, Mark R., Burke, John M., Hempel, Alice L., Williams, Joseph H.
Format: Article
Language:English
Subjects:
Adaptation
Adaptation (Biology)
Ecological competition
Ecological genetics
Evolution
Evolutionary genetics
evolutionary innovations
Genetic hybridization
Genetics
Genotypes
Habitats
hybrid fitness
hybrid zones
Hybridity
Hybridization
Mitochondrial DNA
natural hybridization
Natural selection
Plants
Special Feature: Hybridization and Resistance to Parasites
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper examines two assumptions that have formed the basis for much of the past and present work on hybrid zones. These assumptions derive from the observation that crosses between genetically divergent individuals (e.g., from different subspecies, species, etc.) often give rise to genotypes that are less fertile or less viable than those produced from crosses between genetically similar individuals. The first assumption is that natural hybridization will not affect the evolutionary history of the hybridizing forms because there is a low probability of producing novel genotypes with higher relative fitness. The second viewpoint is more extreme in that it assumes that all hybrid genotypes will be less fit. Even if rare gene flow does occur it will thus not contribute to patterns of diversification or adaptation because the hybrids will always be selected against. Examples from both plant and animal hybridization are discussed that are not consistent with these assumptions. Numerous instances of natural hybridization are used to demonstrate that extremely low fertility or viability of early-generation hybrids (e.g. F1, F2, B1) does not necessarily prevent extensive gene flow and the establishment of new evolutionary lineages. In addition, it is demonstrated that various hybrid genotypes have equivalent or higher fitness than their parents in certain habitats.
ISSN:0012-9658
1939-9170
DOI:10.1890/0012-9658(1999)080[0371:NHHLCY]2.0.CO;2