An inordinate fondness for eukaryotic diversity

Area of Science:

• Evolutionary Biology
• Biodiversity Science
• Phylogenetics

Background:

• Understanding the drivers of species diversity is a fundamental question in evolutionary biology.
• Previous studies suggest significant variation in speciation and extinction rates across the tree of life.

Purpose of the Study:

• To investigate the variation in species diversity across major clades of multicellular eukaryotes.
• To determine if clade age predicts species richness.

Main Methods:

• Compilation of a large dataset encompassing all known living species of plants, animals, and fungi.
• Analysis of 1,397 clades, representing over 1.2 million species.
• Examination of species diversity patterns in relation to clade age and diversification history.

Main Results:

• Demonstrated tremendous variation in species diversity across eukaryotic clades.
• Observed that neither old clades necessarily have many species nor young clades necessarily have few species.
• Found it difficult to predict species richness within a clade based solely on its diversification time.

Conclusions:

• The patterns of species diversity suggest complex and unpredictable speciation and extinction dynamics throughout eukaryotic history.
• This study provides a broad-scale perspective on the factors influencing Earth's biodiversity.