allopolyploidy

Meimberg H, Rice KJ, Milan NF, Njoku CC & McKay JK 2009 Multiple origins promote the ecological amplitude of allopolyploid Aegilops (Poaceae). Am J Bot 96:1262-1273.

• polyploid species can exhibit higher ecological tolerance than their progenitor species
• for allotetraploid species, this higher tolerance is often attributed to the existence of heterosis resulting from entire genome duplication
• multiple origins of allopolyploid species may further promote their ecological success by providing genetic variability in ecological traits underlying local adaptation and range expansion
• we show in a group of allopolyploid species in the genus Aegilops that range size and abundance are correlated with the number of inferred origins
• allopolyploid Aegilops spp. contain multiple chloroplast haplotypes, each identical to haplotypes of the diploid progenitor species, indicating multiple origins as the major source of variation
• the number of inferred origins in each allopolyploid species was correlated to the total area occupied by the allopolyploid and the tendency for the species to be common
• the introduction of genetic variability by multiple origins can increase the ecological amplitude and evolutionary success of allopolyploid species