Neanderthals (Homo neanderthalensis): An adaptive paradox

Abstract

Neanderthals are widely believed to be a cold-adapted species due its unique craniofacial and postcranial characteristics (Harvati 2003), however in recent years this theory has come in to question (Churchill 1998; Holton and Fransiscus 2008; Rae et al. 2011). This essay reviews arguments that the morphology of Neanderthals are adaptations to a cold environment, and critically examines their validity. This essay begins by outlining the distribution and environment of Neanderthals from 300,000 to 30,000 years ago, provide an overview of Neanderthal derived morphological traits and discuss alternative arguments to the cold-adaptation hypotheses for these traits. The increased pneumatisation, prognathism, and the dolichocephalic cranium found in Neanderthals are unlikely to be a direct adaptation to cold climates. These findings are consistent with Neanderthal postcranial morphology, where body size and shape cannot solely be explained by adaptation to the cold. Instead, other theories are explored, such as increased mobility and activity, anterior dental loading, and hormonal anomalies. Evidence reviewed in this article indicates that the unique morphological characteristics of Neanderthals are likely to be the result of a combination of factors, and are not solely due to cold adaptation.