Phylogeny of Neotropical Sicarius sand spiders suggests frequent transitions from deserts to dry forests despite antique, broad-scale niche conservatism

• Published in: Molecular phylogenetics and evolution 2019-11, Vol.140, p.106569-106569, Article 106569
• Main Authors: Magalhaes, I.L.F., Neves, D.M., Santos, F.R., Vidigal, T.H.D.A., Brescovit, A.D., Santos, A.J.
• Format: Article
• Language: English
• Subjects: Africa; Animals; Atacama; Biodiversity; Desert Climate; Dry diagonal; Ecosystem; Forests; Geography; Phylogenetic niche conservatism; Phylogeny; Pleistocene arc hypothesis; Seasonally dry tropical forests; Sicariidae; Spiders - classification; Tropical Climate
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2019.106569

[Display omitted] •Sand spiders are mostly restricted to African and Neotropical dry forests and xeric scrublands.•Divergence between African and Neotropical forms occurred during the Cretaceous.•Speciation events of taxa from Neotropical dry biomes took place in the Miocene.•Lineages from deserts invaded dry forest habitats 2–3 times in their history.•Niches are conserved in broad scale (dry vs. mesic) but labile in small scale (dry vs. dry). Phylogenetic niche conservatism (PNC) shapes the distribution of organisms by constraining lineages to particular climatic conditions. Conversely, if areas with similar climates are geographically isolated, diversification may also be limited by dispersal. Neotropical xeric habitats provide an ideal system to test the relative roles of climate and geography on diversification, as they occur in disjunct areas with similar biotas. Sicariinae sand spiders are intimately associated with these xeric environments, particularly seasonally dry tropical forests (SDTFs) and subtropical deserts/scrublands in Africa (Hexophthalma) and the Neotropics (Sicarius). We explore the role of PNC, geography and biome shifts in their evolution and timing of diversification. We estimated a time-calibrated, total-evidence phylogeny of Sicariinae, and used published distribution records to estimate climatic niche and biome occupancy. Topologies were used for estimating ancestral niches and biome shifts. We used variation partitioning methods to test the relative importance of climate and spatially autocorrelated factors in explaining the spatial variation in phylogenetic structure of Sicarius across the Neotropics. Neotropical Sicarius are ancient and split from their African sister-group around 90 (57–131) million years ago. Most speciation events took place in the Miocene. Sicariinae records can be separated in two groups corresponding to temperate/dry and tropical/seasonally dry climates. The ancestral climatic niche of Sicariinae are temperate/dry areas, with 2–3 shifts to tropical/seasonally dry areas in Sicarius. Similarly, ancestral biomes occupied by the group are temperate and dry (deserts, Mediterranean scrub, temperate grasslands), with 2–3 shifts to tropical, seasonally dry forests and grasslands. Most of the variation in phylogenetic structure is explained by long-distance dispersal limitation that is independent of the measured climatic conditions. Sicariinae have an ancient association to arid lands, suggesting that PNC preven