A crucial design feature of language useful for determining when grammatical language evolved in the human lineage is our ability to combine meaningless units to form a new unit with meaning (combinatoriality) and to further combine these meaningful units into a larger unit with a novel meaning (compositionality). There is overlap between neural bases that underlie hierarchical cognitive functions required for compositionality in both linguistic and nonlinguistic contexts (e.g., tool use). Therefore, evidence of compositional tool use in the archaeological record (...) should signify, at the very least, the cognitive capacity for grammatical language by that point in time. We devise a novel system to evaluate the level of hierarchical nesting of tool components in single tool use activities. In the application of this system, we demonstrate that nonhuman primates, and by extension, the last common ancestor shared by Pan and Homo, are capable of basic combinatoriality; however, their technology does not approach the compositionality observable in modern human tool use. The prehistoric archaeological record supports a continuous evolution of combinatorial tool use into compositional tool use, with evidence for human-like levels of by 0.93 million years ago (Ma), or possibly as early as 1.7 Ma. While compositional language could have lagged behind compositional tool use, if language and technology coevolved according to the Technological Origin for Language hypothesis, which proposes a feedback system between the two, then evidence for hierarchical tool use structures implies a similar level of complexity in linguistic structures. (shrink)

It is commonly argued that the rules of language, as distinct from its semantic features, are the characteristics which most clearly distinguish language from the communication systems of other species. A number of linguists (e.g., Chomsky 1972, 1980; Pinker 1994) have suggested that the universal features of grammar (UG) are unique human adaptations showing no evolutionary continuities with any other species. However, recent summaries of the substantive features of UG are quite remarkable in the very general nature of the features (...) proposed. While the syntax of any given language can be quite complex, the specific rules vary so much between languages that the truly universal (i.e. innate) aspects of grammar are not complex at all. In fact, these features most closely resemble a set of general descriptions of our richly complex semantic cognition, and not a list of specific rules. General principles of the evolutionary process suggest that syntax is more properly understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution. It is argued that grammatical rules used in given languages are likely to be simply conventionalized, invented features of language, and not the result of an innate, grammar-specific module. The grammatical and syntactic regularities that are found across languages occur simply because all languages attempt to communicate the same sorts of semantic information. (shrink)

We present a new road map for research on “How the Brain Got Language” that adopts an EvoDevoSocio perspective and highlights comparative neuroprimatology – the comparative study of brain, behavior and communication in extant monkeys and great apes – as providing a key grounding for hypotheses on the last common ancestor of humans and monkeys and chimpanzees and the processes which guided the evolution LCA-m → LCA-c → protohumans → H. sapiens. Such research constrains and is constrained by analysis of (...) the subsequent, primarily cultural, evolution of H. sapiens which yielded cultures involving the rich use of language. (shrink)

Evolutionary change occurs most often through the modification of pre-existing structures. What were the pre-existing circuits in our primate ancestors that paved the way for human language, and how did they change in the lineages leading to our present condition? Among the neural modifications that were critical for human language, there are two of special interest: The origin and evolution of the remarkably rich conceptual world that humans share to the exclusion of other primates, and the origin of neural circuitry (...) that underlies various sequential and hierarchical aspects of language, as utilized for example in syntax and word morphology. The fossil record of brain evolution and the archaeological record provide intriguing clues about these processes. (shrink)

We discuss two problems for a general scientific understanding of language, sequences and synergies: how language is an intricately sequenced behavior and how language is manifested as a multidimensionally structured behavior. Though both are central in our understanding, we observe that the former tends to be studied more than the latter. We consider very general conditions that hold in human brain evolution and its computational implications, and identify multimodal and multiscale organization as two key characteristics of emerging cognitive function in (...) our species. This suggests that human brains, and cognitive function specifically, became more adept at integrating diverse information sources and operating at multiple levels for linguistic performance. We argue that framing language evolution, learning, and use in terms of synergies suggests new research questions, and it may be a fruitful direction for new developments in theory and modeling of language as an integrated system. (shrink)

The belief that syntax is an innate, autonomous, species-specific module is highly questionable. Syntax demonstrates the mosaic nature of evolutionary change, in that it made use of (and led to the enhancement of) numerous preexisting neurocognitive features. It is best understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution.

We present a new road map for research on “How the Brain Got Language” that adopts an EvoDevoSocio perspective and highlights comparative neuroprimatology – the comparative study of brain, behavior and communication in extant monkeys and great apes – as providing a key grounding for hypotheses on the last common ancestor of humans and monkeys and chimpanzees and the processes which guided the evolution LCA-m → LCA-c → protohumans → H. sapiens. Such research constrains and is constrained by analysis of (...) the subsequent, primarily cultural, evolution of H. sapiens which yielded cultures involving the rich use of language. (shrink)

The existence of linked regularities in size among brain components across species is, by itself, not a strong argument against the importance of behavioral selection in brain evolution. A careful consideration of hominid brain evolution suggests that brain components can change their scaling relationships over time, and that behavioral selection was likely crucial. The best neuroanatomical index of a given behavioral ability can only be determined empirically, not through comparative analysis of brain anatomy alone.

Reconstructing the evolution of cognition requires maximal extraction of information from very sparse data. The role that archaeology plays in this process is important, but strong empirical tests of plausible hypotheses are absolutely critical. Quantitative measures of symmetry must be devised, a much deeper understanding of nonhuman primate spatial cognition is needed, and a better understanding of brain/behavior relationships across species is necessary to properly ground these hypotheses.