Data from: Multiple continental radiations and correlates of diversification in Lupinus (Leguminosae): testing for key innovation with incomplete taxon sampling

Replicate radiations provide powerful comparative systems to address
questions about the interplay between opportunity and innovation in
driving episodes of diversification and the factors limiting their
subsequent progression. However, such systems have been rarely documented
at intercontinental scales. Here, we evaluate the hypothesis of multiple
radiations in the genus Lupinus (Leguminosae), which exhibits some of the
highest known rates of net diversification in plants. Given that
incomplete taxon sampling, background extinction, and lineage-specific
variation in diversification rates can confound macroevolutionary
inferences regarding the timing and mechanisms of cladogenesis, we used
Bayesian relaxed clock phylogenetic analyses as well as MEDUSA and BiSSE
birth–death likelihood models of diversification, to evaluate the
evolutionary patterns of lineage accumulation in Lupinus. We identified 3
significant shifts to increased rates of net diversification (r) relative
to background levels in the genus (r = 0.18–0.48 lineages/myr). The
primary shift occurred approximately 4.6 Ma (r = 0.48–1.76) in the montane
regions of western North America, followed by a secondary shift
approximately 2.7 Ma (r = 0.89–3.33) associated with range expansion and
diversification of allopatrically distributed sister clades in the Mexican
highlands and Andes. We also recovered evidence for a third independent
shift approximately 6.5 Ma at the base of a lower elevation eastern South
American grassland and campo rupestre clade (r = 0.36–1.33). Bayesian
ancestral state reconstructions and BiSSE likelihood analyses of
correlated diversification indicated that increased rates of speciation
are strongly associated with the derived evolution of perennial life
history and invasion of montane ecosystems. Although we currently lack
hard evidence for “replicate adaptive radiations” in the sense of
convergent morphological and ecological trajectories among species in
different clades, these results are consistent with the hypothesis that
iteroparity functioned as an adaptive key innovation, providing a
mechanism for range expansion and rapid divergence in upper elevation
regions across much of the New World.