There is substantial variation in language experience, yet there is surprising similarity in the language structure acquired. Constraints on language structure may be external modulators that result in this canalization of language structure, or else they may derive from the broader, communicative environment in which language is acquired. In this paper, the latter perspective is tested for its adequacy in explaining robustness of language learning to environmental variation. A computational model of word learning from cross-situational, multimodal information was constructed and (...) tested. Key to the model's robustness was the presence of multiple, individually unreliable information sources to support learning. This “degeneracy” in the language system has a detrimental effect on learning, compared to a noise-free environment, but has a critically important effect on acquisition of a canalized system that is resistant to environmental noise in communication. (shrink)

This article reviews the edited volume “Evolvability: A Unifying Concept in Evolutionary Biology?” through biological and philosophical lenses. The book provides diverse angles on evolvability, which is affected by various hierarchical levels, timescales, and types of variation, thus moving beyond a purely genomics perspective. Evolvability is important to biosemiotics because understanding the dynamics of topological genotype spaces could help one better comprehend the phenotypic spaces of meaning, as developmental codes and interrelations can influence the emergence of biological novelty over time. (...) This book is successful in provoking thought on evolvability's role as both a product and a driver of evolutionary innovations and explores the philosophical implications of how evolution has the capacity to generate novel forms of meaning. (shrink)

Degeneracy is ubiquitous across biological systems where structurally different elements can yield a similar outcome. Degeneracy is of particular interest in neuroscience too. On the one hand, degeneracy confers robustness to the nervous system and facilitates evolvability: Different elements provide a backup plan for the system in response to any perturbation or disturbance. On the other, a difficulty in the treatment of some neurological disorders such as chronic pain is explained in light of different elements all of which contribute to (...) the pathological behavior of the system. Under these circumstances, targeting a specific element is ineffective because other elements can compensate for this modulation. Understanding degeneracy in the physiological context explains its beneficial role in the robustness of neural circuits. Likewise, understanding degeneracy in the pathological context opens new avenues of discovery to find more effective therapies. (shrink)