Three possible determinants of graded structure (typicality) were observed in common taxonomic categories and goal-derived categories: (1) an exemplar's similarity to ideals associated with goals its category serves; (2) an exemplar's similarity to the central tendency of its category (family resemblance); and (3) an exemplar's frequency of instantiation (people's subjective estimates of how of...

It is thought that semantic memory represents taxonomic information differently from thematic information. This study investigated the neural basis for the taxonomic-thematic distinction in a unique way. We gathered picture-naming errors from 86 individuals with poststroke language impairment (aphasia). Error rates were determined separately for taxonomic errors ("pear" in response to apple) an...

Species numbers are increasing rapidly. This is due mostly to taxonomic inflation, where known subspecies are raised to species as a result in a change in species concept, rather than to new discoveries. Yet macroecologists and conservation biologists depend heavily on species lists, treating them as accurate and stable measures of biodiversity. Deciding on a standardized, universal species lis...

Climate warming is predicted to alter species interactions, which could potentially lead to extinction events. However, there is an ongoing debate whether the effects of warming on biodiversity may be moderated by biodiversity itself. We tested warming effects on soil nematodes, one of the most diverse and abundant metazoans in terrestrial ecosystems, along a gradient of environmental complexit...

Microbial communities can display large variation in taxonomic composition, yet this variation can coincide with stable metabolic functional structure and performance. The mechanisms driving the taxonomic variation within functional groups remain largely unknown. Biotic interactions, such as predation by phages, have been suggested as potential cause of taxonomic turnover, but the conditions fo...

Human-induced biotic homogenization resulting from landscape change and increased competition from widespread generalists or 'winners', is widely recognized as a global threat to biodiversity. However, it remains unclear what aspects of landscape structure influence homogenization. This paper tests the importance of interspecific competition and landscape structure, for the spatial homogeneity ...