Data from: Comparative analysis indicates historical persistence and contrasting contemporary structure in sympatric woody perennials of semi-arid south-west Western Australia

We used a comparative approach to assess congruence of phylogeographic and
genetic structure and diversity, demographic signals, and ratios of pollen
to seed dispersal, in the context of species-specific life-history traits,
for two widespread sympatric perennial plant species. We sampled Grevillea
paradoxa and Melaleuca nematophylla across the species’ ranges throughout
the Transitional Rainfall Zone and extending slightly into the Arid Zone
of south-west Western Australia. Both species exhibited range-wide
phylogeographic and contemporary genetic structure. Moderate haplotype
diversity centred in populations on Banded Ironstone Formation (BIF)
outcrops and within the Murchison River gorge supports a hypothesis of
historical persistence and evolution in these mesic refugia. These
features are likely to play important roles in evolutionary persistence
with ongoing climate change. There was little evidence of particularly
complex demographic histories for the region. More limited haplotype
diversity, as well as more limited nuclear genetic diversity and
connectivity, in G. paradoxa was consistent with predictions from
life-history traits of shorter lifespan, lower fecundity, more limited
seed dispersal, and shorter plants, but inconsistent with a prediction of
greater pollen dispersal by bird pollinators. Low pollen to seed dispersal
ratios suggest seed dispersal plays a greater than expected role in
maintaining connectivity in this semi-arid landscape. The study highlights
a need for research that integrates aspects of seed ecology and seed and
pollen dispersal as well as phylogeographic and genetic patterns in
Gondwanan shrublands and other semi-arid landscapes globally.