Synchronous diversification of parachuting frogs (Genus Rhacophorus) on Sumatra and Java

Area of Science:

• Evolutionary biology
• Geology
• Ecology

Background:

• Synchronous diversification in co-distributed species can be influenced by geological and climatological processes.
• Sumatra and Java exhibit complex geological and climatological histories, including significant sea-level fluctuations and mountain range formations.
• These environmental factors may have promoted the diversification of resident species on these islands.

Purpose of the Study:

• To investigate the diversification of the parachuting frog genus Rhacophorus on Sumatra and Java.
• To test for synchronous diversification events driven by geological and climatological changes.
• To determine the role of sea-level fluctuations and allopatric isolation in species divergence.

Main Methods:

• Phylogenetic analysis using mitochondrial and nuclear DNA sequence data.
• Genome-wide single nucleotide polymorphisms (SNPs) for phylogenetic structure and divergence time estimation.
• Comparative analysis of co-distributed taxa to identify synchronous diversification.

Main Results:

• Evidence supporting synchronous divergence between sister-species pairs from Sumatra and Java approximately 9 million years ago.
• Identification of synchronous population divergence in four co-distributed taxa on Sumatra around 5.6 million years ago.
• Confirmation that sister species diverged in allopatry on Sumatra.

Conclusions:

• Sea-level fluctuations significantly impacted species divergence on Sumatra and Java.
• Geological and climatological processes, particularly sea-level changes, promoted allopatric isolation and subsequent divergence in Rhacophorus frogs.
• The findings highlight the role of environmental dynamics in shaping amphibian biodiversity in island ecosystems.