Relative tooth size, Bayesian inference, and Homo naledi.

Area of Science:

• Paleoanthropology
• Evolutionary Biology
• Dental Morphology

Background:

• Homo naledi fossils were dated to ~335-236 ka.
• Understanding Homo naledi's evolutionary position is crucial for human origins research.

Purpose of the Study:

• To estimate phenetic affinities of Homo naledi using size-corrected tooth crown measurements.
• To identify dental evolutionary trends in Homo naledi and related hominins.

Main Methods:

• Tooth crown dimensions were scaled by their geometric mean for size-independent comparison.
• Bayesian inference and gap-weighting were employed for phylogenetic analysis.

Main Results:

• Homo naledi was placed as a sister taxon to Homo habilis based on relative tooth size.
• Phylogenetic analysis nested Homo naledi within the Homo genus, showing affinities with early Homo and australopiths.

Conclusions:

• Relative tooth size analysis provides insights into hominin dental evolution.
• Findings support an earlier origin for Homo naledi than previously suggested by its discovery context.