Comparative perspective on antemortem tooth loss in Neandertals

Area of Science:

• Paleoanthropology
• Evolutionary Biology
• Primate Anatomy

Background:

• Antemortem tooth loss (AMTL) in Neandertals is debated as evidence for human-like behaviors.
• Previous interpretations lack comparative data on AMTL frequencies across Neandertals, recent humans, and non-human primates.
• Understanding AMTL variation is crucial for inferring Neandertal life history and behaviors.

Purpose of the Study:

• To quantitatively compare antemortem tooth loss (AMTL) frequencies in Neandertals with recent human hunter-gatherers and non-human primates.
• To assess whether Neandertal AMTL rates are comparable to modern humans or exceed those of non-human primates.
• To explore the implications of AMTL frequencies for understanding Neandertal life history and behaviors.

Main Methods:

• Binomial-normal regression models were applied within a Bayesian framework.
• Data included 25 Neandertal specimens, 310 recent human hunter-gatherers, 61 chimpanzees, 38 orangutans, and 75 baboons.
• Models considered tooth type, taxon, and estimated age at death to predict the probability of AMTL.

Main Results:

• Neandertals exhibited higher odds of AMTL than orangutans and baboons, similar to or lower than chimpanzees.
• Neandertal AMTL frequencies were lower than recent humans, assuming human-like senescence rates.
• Neandertal AMTL rates were intermediate between chimpanzees and recent humans if faster senescence was assumed.

Conclusions:

• Neandertal AMTL frequencies are only above non-human primates if they possessed more rapid life histories than modern humans.
• The observed AMTL frequencies in Neandertals suggest either non-human-like life histories or AMTL patterns.
• The behavioral significance of Neandertal AMTL is ambiguous due to low frequencies and substantial variation within recent human populations.