High speciation rate at temperate latitudes explains unusual diversity gradients in a clade of ectomycorrhizal fungi

Santiago Sánchez-Ramírez, Rampal S Etienne, Jean-Marc Moncalvo

Research output: Contribution to journalArticleAcademicpeer-review

18 Citations (Scopus)

Abstract

Understanding the patterns of biodiversity through time and space is a challenging task. However, phylogeny-based macroevolutionary models allow us to account and measure many of the processes responsible for diversity build-up, namely speciation and extinction. The general latitudinal diversity gradient (LDG) is a well-recognized pattern describing a decline in species richness from the equator pole-wards. Recent macroecological studies in ectomycorrhizal (EM) fungi have shown that their LDG is shifted, peaking at temperate rather than tropical latitudes. Here we investigate this phenomenon from a macroevolutionary perspective, focusing on a well-sampled group of edible EM edible mushrooms from the genus Amanita -the Caesar's mushrooms, which follow similar diversity patterns. Our approach consisted in applying a suite of models including: (1) non-trait-dependent time-varying diversification (BAMM), (2) continuous trait-dependent diversification (QuaSSE), and (3) diversity-dependent diversification (DDD). In short, results give strong support for high speciation rates at temperate latitudes (BAMM and QuaSSE). We also find some evidence for different diversity-dependence thresholds in 'temperate' and 'tropical' subclades, and little differences in diversity due to extinction. We conclude that our analyses on the Caesar's mushrooms give further evidence of a temperate-peaking LDG in EM fungi, highlighting the importance and the implications of macroevolutionary processes in explaining diversity gradients in microorganisms. This article is protected by copyright. All rights reserved.

Original languageEnglish
Pages (from-to)2196-2209
JournalEvolution
Volume69
Issue number8
DOIs
Publication statusPublished - 14-Jul-2015

Keywords

  • MOLECULAR PHYLOGENIES
  • HISTORICAL BIOGEOGRAPHY
  • SPECIES-DIVERSITY
  • FOSSIL RECORD
  • TRICHOLOMA-SCALPTURATUM
  • ECOLOGICAL LIMITS
  • EXTINCTION RATES
  • AMANITA-MUSCARIA
  • GLOBAL PATTERNS
  • DIVERSIFICATION

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