Historical biogeographical analysis of the Udoteaceae (Bryopsidales, Chlorophyta) elucidates origins of high species diversity in the Central Indo-Pacific, Western Indian Ocean and Greater Caribbean regions

Ancient Tethyan Vicariance and Long-Distance Dispersal Drive Global Diversification and Cryptic Speciation in the Red Seaweed Pterocladiella

“…As reported in other marine animals and seaweeds ( Williams and Duda, 2008 ; Leliaert et al, 2018 ), early divergence in Pterocladiella preceded the barriers separating the Atlantic and Indo-Pacific (EPB, OWB, and IOP); these major geological events do not appear to have affected diversification rates in Pterocladiella . Diversification of Pterocladiella occurred relatively consistent over ~100 million years from the Early Cretaceous to the present, as has been found in other seaweeds ( Vieira et al, 2017 ; Leliaert et al, 2018 ; Lagourgue et al, 2022 ). In contrast, for some groups of corals, fishes, and gastropods, increased diversification rates have been inferred in the Late Cretaceous or in the Oligo-Miocene, likely due to geographical complexity caused by tectonic changes ( Williams and Duda, 2008 ; Leprieur et al, 2016 ).…”

“…Age estimates indicate that the Indo-Pacific species arose during the Eocene to Miocene. The emergence of various shallow-water habitats in the Tethys Sea during these periods likely provided opportunities for diversification and the long-term persistence of species, as has also been suggested for other seaweeds such as Portieria , Lobophora , and Udoteaceae ( Vieira et al, 2017 ; Leliaert et al, 2018 ; Lagourgue et al, 2022 ).…”

“…Recent global historical biogeographical studies of representative seaweeds have highlighted some commonalities and differences in patterns of species ranges, origin, and diversification. Benthic marine algae are typically genus rich in temperate seas ( Kerswell, 2006 ), while species richness is high in the tropics, especially in the Central Indo-Pacific such as for the red seaweed Portieria , brown seaweed Lobophora and Sargassum , and green seaweed Udoteaceae ( Vieira et al, 2017 ; Leliaert et al, 2018 ; Yip et al, 2020 ; Lagourgue et al, 2022 ). Although there are few genus-level studies, some are originated during the Cretaceous period from various regions, such as Australasia, Eastern Asia, or broad range in the Tethys Sea; their diversification occurred relatively constantly over time and long-distance dispersal event are more important mode of speciation than vicariance ( Hommersand, 1990 ; Vieira et al, 2017 ; Leliaert et al, 2018 ; Xu et al, 2018 ).…”