Assessing the causes of diversification slowdowns: temperature-dependent and diversity-dependent models receive...

Area of Science:

• Evolutionary Biology
• Phylogenetics
• Paleoclimatology

Background:

• Diversification rates fluctuate over geological time, but the drivers of these changes are debated.
• Previous research often emphasized biotic factors like diversity dependence, with limited testing of abiotic influences like climate change on diversification.
• Understanding these dynamics is crucial for reconstructing evolutionary history and predicting future biodiversity.

Discussion:

• This study applies advanced phylogenetic models to 218 tetrapod families to investigate diversification patterns.
• Both diversity-dependent and temperature-dependent models were tested, alongside constant and time-dependent models.
• The analysis confirms widespread diversification slowdowns across tetrapod families.

Key Insights:

• Phylogenetic analyses reveal that temperature-dependent diversification models are as strongly supported as diversity-dependent models.
• This suggests that climatic shifts, such as Cenozoic cooling, may have significantly impacted speciation rates.
• The findings challenge the sole emphasis on biotic factors and highlight the role of abiotic influences.

Outlook:

• Future research should integrate both biotic and abiotic factors to achieve a more comprehensive understanding of diversification dynamics.
• Further studies can explore specific climatic events and their differential impacts across various taxa.
• This integrated approach will refine our models of macroevolutionary processes.