Paleobiome dynamics shaped a large Gondwanan plant radiation

Area of Science:

• Ecology
• Evolutionary Biology
• Paleoclimatology

Background:

• Adaptive radiation theory suggests rapid diversity accumulation in new environments, slowing as competition increases.
• Understanding historical environmental changes is crucial for explaining current biodiversity patterns, but this is challenging.

Purpose of the Study:

• To investigate how paleobiome dynamics influenced the diversification of Proteaceae (Grevilleoideae) over 120 million years.
• To determine the relative importance of historical ecological opportunity versus current environmental factors in shaping plant diversity.

Main Methods:

• Modeled paleobiome dynamics over a 120 million-year period.
• Generated a nuclear phylogenomic dataset for approximately 700 species (74% of the clade).
• Analyzed diversification rates in relation to biome expansion and contraction.

Main Results:

• Diversification rates in Grevilleoideae were strongly linked to ecological opportunities from emerging and expanding biomes.
• Rapid diversification occurred in newly emerging and expanding biomes.
• Long-established biomes showed higher species richness but lower diversification rates, nearing equilibrium.

Conclusions:

• Past climatic and geological history significantly and heterogeneously impacts current plant diversity.
• Biodiversity patterns are a legacy of historical diversification, often decoupled from present-day biome characteristics.