We explored macroevolutionary trends and factors influencing heterogeneity in species diversity within golden orbweaver spiders. Heterogeneity in speciation and extinction was detected across the phylogenetic tree, including accelerated extinction rates in the extremely sexually size dimorphic genus Nephila. We then tested several organismal (phenotypic extremeness and dispersal propensity) and environmental factors (climate type and landmass type) for their influence on diversification, however, multiple analyses suggested these factors play little to no role in the process. We concluded that diversification in these spiders might not be influenced by a specific factor, but instead follows the recently proposed hypothesis of universal diversification dynamics across the tree of life.
Macroevolutionary rate inference using two methods. BAMM phylorate plots show speciation and extinction rate dynamics in the nephilid phylogeny. Colours denote relative intensity of speciation and extinction along branches. Grey dots signify the location of a shift in diversification rate, inferred by MEDUSA. It detected increased diversification in the genus Herennia (visually presented by H. eva; own photograph) relative to the rest of the phylogeny.