Neanderthal language revisited: not only us

Abstract

Here we re-evaluate our 2013 paper on the antiquity of language (Dediu and Levinson, 2013) in the light of a surge of new information on human evolution in the last half million years. Although new genetic data suggest the existence of some cognitive differences between Neanderthals and modern humans -fully expected after hundreds of thousands of years of partially separate evolution, overall our claims that Neanderthals were fully articulate beings and that language evolution was gradual are further substantiated by the wealth of new genetic, paleontological and archeological evidence briefly reviewed here. IntroductionIn 2013 we published a paper [1] arguing that vocal language has had a long and gradual evolution in the 1.5 my since Homo erectus, and that Neanderthals were articulate humans, not very different from us. We marshaled paleontological, archeological and genetic evidence against the saltationist view that language evolved abruptly within the last 100 ky (e.g. [2]). Since then there has been a flurry of new evidence from paleontology, archeology and ancient DNA that, we argue here, largely supports our views of a much deeper antiquity and gradualism. The human treeOne striking finding is that many human lineages were coexisting just 300 kya (including Homo naledi, Homo floresiensis, Denisovans, Neanderthals and even anatomically modern humans [3 ]), another being the degree of reticulation in the human tree evidenced by genetics. Recent data suggests that at least 50 ky of interactions on a vast geographic scale from the Levant to Siberia and Western Europe gave plenty of scope for interbreeding; Figure 1 shows some of the gene flow across the Neanderthals, Denisovans and ourselves.The ancestors of Neanderthals and Denisovans left Africa c. 650 kya, and by 450 kya had diverged into these two lineages, and there are indications of early Neanderthal and Denisovan interbreeding [4], and of interbreeding between Denisovans and yet another archaic hominin. The Neanderthals then interbred with anatomically modern humans (AMH) on at least three occasions, likely when AMH first came into the Levant 100-120 kya [5 ,6], and also during AMH's move into glacial Europe (c. 50 kya [7]). For example, a Siberian Neanderthal has AMH genes introgressed c. 110 kya [7], and an early AMH with Neanderthal anatomical features c. 40 kya from Romania [8] had Neanderthal ancestry just 4-6 generations before [9]. Recent data suggests that while Neanderthals and Denisovans clearly form a clade, the mtDNA groups the former with AMH due to their original mtDNA being replaced by an AMH-like lineage probably through interbreeding before c. 270 kya [10]. It is now clear that such interbreeding did leave traces in contemporary modern humans outside Africa at the level of a few percent of the genome, with regional and inter-individual variation probably due to repeated interbreeding with Neanderthals and Denisovans [5 ,11 ,12 ]. Contact between human lineages is also revealed by other lines of evidence including the oral commen...

A catalog of single nucleotide changes distinguishing modern humans from archaic hominins

“…. 1995), for which the ancestral Neanderthal-like allele has not been observed in 1,000s of modern human genomes and which has been pointed out before as under positive selection (Castellano et al 2014;Racimo et al 2014;Racimo 2016;Peyrégne et al 2017) We know that archaic hominins likely had certain language-like abilities (Dediu and Levinson 2013;Dediu and Levinson 2018), and hybrids of modern and archaic humans must have survived in their communities , underlining the large overall similarity of these populations.…”

Molecular archaeology of the human brain

“…Furthermore, this indicates that verbal communication evolved in the LCA to all three hominin species (i.e. Homo erectus) several hundred thousand years ago, adding critical insights to a longstanding debate about the timing and origin of human language (47). Surprisingly, the transition to AMHs further accelerated evolution of reward-related decision making and strategic thought as those features most prominently separating us from archaic hominins.…”

Evolutionary Dynamics Do Not Motivate a Single-Mutant Theory of Human Language

“…By diffusing the proposed evolutionary rationale for a single, undecomposable computational innovation, we challenge one of the central theory-external motivations for Merge. Combined with mounting evidence from the archeological record that goes against a very recent 'great leap forward' (25,26) and that indicates that the ability for language is older and evolved over a longer time than hitherto thought (27)(28)(29), as well as the rarity of truly fixed mutations in the modern human lineage (30)(31)(32), we are inclined to argue that evidence favors the view that gene-culture co-evolution is a more compelling approach to the human language faculty. This view predicts that any innate predispositions for language amount to defeasible inductive biases, each of which weakly constrains behavior on its own, but makes a significant contribution thanks to the intervention of culture (33,34), and therefore re-frames the evolutionary explanandum to include the social and cognitive conditions that facilitate culture (35,36).…”