Data from: Contrasting diversity and demographic signals in sympatric narrow range endemic shrubs of the southwest Western Australian semi-arid zone

Comparative studies of sympatric species that integrate both
phylogeographical and population genetic approaches provide insight into
how demographic events and life history traits shape adaptive potential
and drive species persistence. Such studies are rare for species-rich and
strongly structured environments, especially those of the southern
hemisphere. For two sympatric, perennial shrubs of the south-west Western
Australian semi-arid zone, Grevillea globosa and Mirbelia sp.
Bursarioides, we assessed historical and contemporary genetic diversity
and structure, demographic processes and ratios of pollen to seed
dispersal. Phylogeographical structure was not detected and haplotype
networks were star-like. Number of haplotypes, nucleotide diversity,
haplotype diversity, and allelic diversity were statistically
significantly lower for G. globosa than for M. sp. Bursarioides. Levels of
haplotype divergence and more contemporary genetic divergence and expected
heterozygosity were lower for G. globosa than for M. sp. Bursarioides, but
differences were not statistically significant. Both species exhibited
signals of isolation by distance and low pollen to seed dispersal ratios
(5.26:1 and 6.88:1). Grevillea globosa displayed signals of historical and
contemporary demographic expansion. Results imply an important role for
aspects of seed ecology that impact population demography, as well as
direct dispersal and a significant contribution of seed dispersal to
genetic connectivity in a semi-arid landscape.