Hybridization and speciation in angiosperms: a role for pollinator shifts?

Mark W Chase,Ovidiu Paun,Michael F Fay

doi:10.1186/1741-7007-8-45

Abstract

The majority of convincingly documented cases of hybridization in angiosperms has involved genetic introgression between the parental species or formation of a hybrid species with increased ploidy; however, homoploid (diploid) hybridization may be just as common. Recent studies, including one in BMC Evolutionary Biology, show that pollinator shifts can play a role in both mechanisms of hybrid speciation.See research article http://www.biomedcentral.com/1471-2148/10/103

Highlights

The majority of convincingly documented cases of hybridization in angiosperms has involved genetic introgression between the parental species or formation of a hybrid species with increased ploidy; homoploid hybridization may be just as common
There appear to be genetic limits having to do with physical rearrangements of parental chromosomes that make polyploidy more likely when the parental species are distantly related
Docu menting allopolyploidy is relatively easy and involves demonstrating that the hybrids have twice as many chromosomes as the parental species and that they retain fixed polymorphisms at protein-coding loci as documented by either protein studies, which were common in the 1980 and 1990s, or DNA sequencing/ fingerprinting, which are the current methods of choice

Summary

Introduction

The majority of convincingly documented cases of hybridization in angiosperms has involved genetic introgression between the parental species or formation of a hybrid species with increased ploidy; homoploid (diploid) hybridization may be just as common. The second method, which relies upon the assumption that hybrid speciation involves recombination [6] and homogeniza tion of parental homologues, is by far the most powerful, but it requires DNA sequences from a large number of loci and knowledge of their chromosome positions.

Results

Conclusion