Title of article :
Polyploidy and Diversification: A Phylogenetic Investigation in Rosaceae
Author/Authors :
Jana C. Vamosi and Timothy A. Dickinson، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Abstract :
Polyploidy has been described both as an evolutionary dead end and as a major engine of diversification for
angiosperms. Two recent studies have found that genera with higher proportions of polyploid species are more
species rich. Here, we investigate patterns of diversification and polyploidy by performing traditional and
phylogenetically corrected analyses within the Rosaceae. We find that polyploidy is associated with increased
species richness and then differentiate between three alternative hypotheses for this pattern: (1) that polyploidy
is associated with herbaceous growth habit, a trait that is in turn associated with increased species richness; (2)
that polyploid clades are more evolutionarily successful (i.e., experience increased speciation and/or fewer
extinction events) than diploid clades, perhaps because of the increase in genomic content or the increase in
plant/flower size that often accompanies polyploidization; and (3) that the polyploidization events themselves,
along with the reproductive isolation from the parental clade(s) that follows polyploidization, are responsible
for the increased species richness observed in clades with a high proportion of polyploids. There is no evidence
that polyploidy and herbaceous growth habit were correlated or that polyploid clades are more species rich
than their diploid sister groups. We posit that the third hypothesis has the greatest potential for explaining the
pattern of higher species richness of polyploid clades.
Keywords :
diversification , Extinction , Phylogenetic analysis , speciation. , Rosaceae
Journal title :
International Journal of Plant Sciences
Journal title :
International Journal of Plant Sciences