Baboon phylogeny as inferred from complete mitochondrial genomes

Area of Science:

• Primatology
• Evolutionary Biology
• Genomics

Background:

• Baboons (genus Papio) are crucial models for understanding savanna species evolution.
• Previous studies using partial mitochondrial DNA (mtDNA) revealed complex baboon species relationships and unresolved basal divergences.
• Large credibility intervals in divergence time estimates hindered precise evolutionary insights.

Purpose of the Study:

• To reconstruct a robust baboon phylogeny using complete mitochondrial genome sequences.
• To re-estimate divergence times with improved precision.
• To resolve the most basal splits within baboon lineages.

Main Methods:

• Sequencing of complete mitochondrial genomes from ten baboon specimens representing major lineages.
• Phylogenetic analysis to reconstruct evolutionary relationships.
• Divergence time estimation using molecular clock methods.

Main Results:

• Confirmed para- and polyphyletic relationships among most baboon species, consistent with earlier findings.
• Provided younger divergence time estimates with significantly narrowed credibility intervals, enhancing precision.
• Failed to resolve the earliest divergences, leaving ambiguity between a southern population split or a major southern-northern clade split.

Conclusions:

• Complete mitochondrial genome sequencing significantly improves phylogenetic robustness and divergence time accuracy compared to partial sequences.
• Despite advancements, resolving the deepest baboon evolutionary splits requires further investigation.
• The study highlights the utility and limitations of whole mitochondrial genomes in primate phylogenetics.