Pleistocene climatic changes drive diversification across a tropical savanna

Area of Science:

• Ecology
• Evolutionary Biology
• Genomics

Background:

• Species' responses to climate change are shaped by their traits and landscape-level climate variability.
• Advancements in population genomics and spatial modeling enable inference of past climate impacts on populations and communities.

Purpose of the Study:

• To investigate how climatic tolerances and regional climate history interact to shape lizard responses to late Pleistocene climate change.
• To compare spatial structuring and demographic histories of four lizard species across different climatic regions in the Australian Monsoonal Tropics.

Main Methods:

• Analysis of population genomic data from four codistributed lizard species.
• Spatial modeling to infer lineage diversity and demographic responses.
• Comparison of responses between the Kimberley and Top End regions.

Main Results:

• Divergent spatial structuring and demographic responses were observed in the drier Kimberley region compared to the more mesic Top End.
• Regional climate history and species' climatic tolerances influenced population-level responses to past climate change.

Conclusions:

• The effects of species' traits on climate fluctuation sensitivity are more apparent in climatically marginal regions.
• Conservation strategies for future climate change must consider species-specific or trait-specific approaches, particularly in marginal areas.