Phylogenomic data resolve higher-level relationships within South American Liolaemus lizards

Area of Science:

• Herpetology
• Evolutionary Biology
• Genomics

Background:

• The South American lizard genus Liolaemus is the most species-rich vertebrate radiation in temperate zones, with over 265 species.
• Higher-level phylogenetic relationships within Liolaemus are poorly resolved, hindering evolutionary studies.

Purpose of the Study:

• To resolve the phylogenetic relationships among major clades within the Liolaemus genus using phylogenomic data.
• To provide a robust evolutionary framework for the Liolaemus radiation and test macroevolutionary hypotheses.

Main Methods:

• Utilized 584 nuclear loci obtained via targeted sequence capture for phylogenetic analysis.
• Employed Bayesian divergence dating with 44 protein-coding genes to estimate divergence times.
• Conducted phylogenetic network analyses on SNP data to detect hybridization.

Main Results:

• The study supports the division of Liolaemus into two subgenera and resolves many major clade relationships within Eulaemus with strong support.
• Estimated the split of the two Liolaemus subgenera at approximately 19.7 million years ago (mya).
• Diversification within Eulaemus initiated around 15.05 mya during the Mid-Miocene, with evidence of two hybridizing events.

Conclusions:

• The phylogenomic approach successfully resolved complex evolutionary relationships within the Liolaemus genus.
• The established phylogenetic hypothesis provides a foundation for investigating macroevolutionary patterns in this species-rich radiation.
• Identification of hybridization events adds complexity to the understanding of Liolaemus evolution.