Language evolution resulted from changes in our biology, behavior, and culture. One source of these changes might be human self-domestication. Williams syndrome (WS) is a clinical condition with a clearly defined genetic basis which results in a distinctive behavioral and cognitive profile, including enhanced sociability. In this paper we show evidence that the WS phenotype can be satisfactorily construed as a hyper-domesticated human phenotype, plausibly resulting from the effect of the WS hemideletion on selected candidates for domestication and neural crest (NC) function. Specifically, we show that genes involved in animal domestication and NC development and function are significantly dysregulated in the blood of subjects with WS. We also discuss the consequences of this link between domestication and WS for our current understanding of language evolution.

Language evolution resulted from changes in our biology, behavior, and culture. One source of these changes might be human self-domestication. Williams syndrome (WS) is a clinical condition with a clearly defined genetic basis and resulting in a distinctive behavioral and cognitive profile, including enhanced sociability. In this paper we show evidence that the WS phenotype can be satisfactorily construed as a hyper-domesticated human phenotype, plausibly resulting from the effect of the WS hemydeletion on several candidates for domestication and neural crest function. We also discuss the consequences of this link between domestication and WS for our current understanding of language evolution.

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Autism spectrum disorders and Williams syndrome exhibit quite opposite features in the social domain, but also share some common underlying behavioral and cognitive deficits. It is not clear, however, which genes account for the attested differences (and similarities) in the socio-cognitive domain. In this article, we adopted a comparative molecular approach and looked for genes that might be differentially (or similarly) regulated in the blood of subjects with these two conditions. We found a significant overlap between differentially expressed genes compared to neurotypical controls, with most of them exhibiting a similar trend in both conditions, but with genes being more dysregulated in Williams syndrome than in autism spectrum disorders. These genes are involved in aspects of brain development and function (particularly dendritogenesis) and are expressed in brain areas (particularly the cerebellum, the thalamus, and the striatum) of relevance for the autism spectrum disorder and the Williams syndrome etiopathogenesis. Lay abstract Autism spectrum disorders and Williams syndrome are complex cognitive conditions exhibiting quite opposite features in the social domain: whereas people with autism spectrum disorders are mostly hyposocial, subjects with Williams syndrome are usually reported as hypersocial. At the same time, autism spectrum disorders and Williams syndrome share some common underlying behavioral and cognitive deficits. It is not clear, however, which genes account for the attested differences (and similarities) in the socio-cognitive domain. In this article, we adopted a comparative molecular approach and looked for genes that might be differentially (or similarly) regulated in the blood of people with these conditions. We found a significant overlap between genes dysregulated in the blood of patients compared to neurotypical controls, with most of them being upregulated or, in some cases, downregulated. Still, genes with similar expression trends can exhibit quantitative differences between conditions, with most of them being more dysregulated in Williams syndrome than in autism spectrum disorders. Differentially expressed genes are involved in aspects of brain development and function (particularly dendritogenesis) and are expressed in brain areas (particularly the cerebellum, the thalamus, and the striatum) of relevance for the autism spectrum disorder and the Williams syndrome etiopathogenesis. Overall, these genes emerge as promising candidates for the similarities and differences between the autism spectrum disorder and the Williams syndrome socio-cognitive profiles.

Feralization is the process by which a once-domesticated animal returns to a wild-like state due to desocialization from humans. Whether feralization results from a true reversion of the physiological and genetic mechanisms underlying domestication or whether it involves a return to a wild state by other means is still a controversial issue. In this paper we provide a comparative account of both processes. We highlight the physical, behavioral, and neurobiological traits of domesticated animals that appear to be reversible, as well as those others that are resistant to change in cases of feralization. Additionally, we compare the genetic signatures of domestication and feralization, and identify a core set of genes involved in both process that could account for the reversion of selected traits in feralized animals. We conclude with a discussion regarding the ultimate reasons for the differences and overlaps attested between feralization and domestication.