AimExceptions to the quasi‐ubiquitous latitudinal diversity gradient (LDG) have been poorly studied. A reverse LDG, when species richness (SR) increases away from the Equator, has been suggested for several taxa and entire biomes. The Neotropical seasonally dry tropical forests (SDTF) are a well‐known example of a reverse LDG that could be caused by the climatic stability of Pleistocene Refugia and dispersion from distinct source areas. Here, we test these predictions under a spatial and phylogenetic framework.LocationNeotropics.TaxonWoody plants.MethodsWe used a recent species‐level seed plant phylogeny and the DRYFLOR dataset to evaluate the geographic patterns of phylogenetic diversity (PD) and structure of woody plant assemblages associated with the Neotropical SDTFs. We conducted spatial regressions to test the effect of climatic instability since the Last Glacial Maximum (LGM) on assemblages’ residual PD (controlling for SR) and null model analysis to evaluate their phylogenetic structure using the Net Relatedness Index.ResultsPhylogenetic diversity of the Neotropical SDTFs increased away from the Equator, likely driven by SR. This pattern was not related to climatic instability since the LGM. Phylogenetic structure of SDTF assemblages showed considerable spatial patterning, with significant phylogenetic clustering in the Mesoamerica and Caatinga regions.Main conclusionThe reverse latitudinal SR gradient of the Neotropical SDTF assemblages is mirrored by their PD. Phylogenetic history seems to have influenced such patterns differently across the Neotropics with no relationship to climatic stability since the LGM, where particular SDTF nuclei previously suggested as Pleistocene refugia served as cradles and source areas for the current diversity pattern of the biome.

Measuring the dispersal ability of birds is particularly challenging and thus researchers have relied on the extended use of morphological proxies as surrogates for such ability. However, few studies have tested the relationship between morphological proxies and other dispersal-related traits. In this study, we test the relationship of the most commonly used morphological proxy for dispersal—the Hand-Wing Index (HWI)—with traits highly associated with dispersal abilities, such as geographic range size, migratory behaviour and migratory distances. We used the Emberizoidea superfamily to evaluate these relationships and measured the HWI of 2520 individuals from 431 species (almost half of all the species in the superfamily). We first estimated the phylogenetic signal of HWI and searched for the best evolutionary model to explain its variation. We then performed PGLS analyses to assess the relationships between HWI and dispersal abilities. Our results showed that HWI has a strong phylogenetic signal and is positively related to dispersal abilities. Our findings support the use of HWI as a viable morphological proxy for dispersal in birds.