Palaearctic origin and repeated dispersal over the world shaped the biogeographic history of the saprophytic genus Coprinopsis (Psathyrellaceae, Basidiomycota)

Aim: The biogeographic history of most fungi is still poorly known, as
well as the patterns and processes responsible for their diversification.
Recent studies uncovered that most fungi have originated and present
higher diversification rates in the temperate zone. The distributional
pattern known for fungi is also different from many plants, animals and
microbes. Using the most comprehensive phylogeny of the saprotrophic genus
Coprinopsis, we aim to infer the biogeographic history and test
evolutionary hypotheses in the genus. Location: Worldwide Taxon: Fungi,
Basidiomycota, Psathyrellaceae, Coprinopsis Methods: We used a four-gene
alignment with 100 species to estimate divergence times using two fossil
calibrations within Agaricales. The chronograms were used to estimate
diversification rates and geographic state-dependent models were applied.
We further reconstructed the ancestral range history of the genus.
Results: Molecular dating estimated that the genus has diverged ca. 41 Ma
(Eocene) and originated in the Palaearctic region. Diversification rates
showed a decreasing pattern towards the present across Coprinopsis,
especially after the Miocene (ca. 14 Ma). The diversification models
dependent on distribution showed cosmopolitan lineages with higher
net-diversification rates. When we compared temperate and tropical
regions, we found that temperate lineages have higher net-diversification
rates. The biogeographic history of Coprinopsis estimated different routes
of dispersal. The most common dispersal route was from the Palaearctic to
the Nearctic (15 times), followed by the Palaeartic to the Neotropics (14
times). Main Conclusions: The study is the first to estimate the
diversification rates and the historical biogeography of the coprinoid
genus Coprinopsis. The diversification dynamics estimates in Coprinopsis
are in agreement with the “generalized diversification rates model”, where
we found higher diversification rates in temperate regions compared to
tropical regions. In general, the ancestral area and major dispersal
routes recovered in the genus are similar to findings in other groups of
fungi.