Experimental evidence for rapid genomic adaptation to a new niche in an adaptive radiation

A substantial part of biodiversity is thought to have arisen from adaptive radiations in which one lineage rapidly diversified into multiple lineages specialized to many different niches. However, selection and drift reduce genetic variation during adaptation to new niches and may thus prevent or slow down further niche shifts. We tested whether rapid adaptation is still possible from a highly derived ecotype in the adaptive radiation of threespine stickleback on the Haida Gwaii archipelago, Western Canada. In a 19-year selection experiment, we let giant sticklebacks from a large blackwater lake evolve in a small clearwater pond without vertebrate predators. A total of 56 whole genomes from the experiment and 26 natural populations revealed that adaptive genomic change was rapid in many small genomic regions and encompassed 75% of the change between 12,000-year-old ecotypes. Genomic change was as fast as phenotypic change in defence and trophic morphology, and both were largely parallel between the short-term selection experiment and long-term natural adaptive radiation. Our results show that functionally relevant standing genetic variation can persist in derived radiation members, allowing adaptive radiations to unfold very rapidly

Aggressive Behaviour and Sleep: History, Review, and Perspectives

The relationship between sleep and behaviour has been studied in the context of several fields. It is known that changes in sleep pattern as well as sleep disorders are intimately linked to both cognitive and behavioural co-morbidities, including aggressive behaviour. Although the relationship between sleep and aggression has been examined from different angles, particularly in the past decade, the literature lacks a comprehensive and broad review of findings on the topic. The current review seeks to condense the content of the literature on sleep and aggressive behaviour by bringing the interface of these two themes to light. Herein, first, historical overview on the studies about this relationship is provided. Following, the basic concepts of both themes are presented in a concise manner, thus enabling a critical and summarized discussion regarding the main findings in both laboratory animals and humans concerning the association of sleep and aggressive behaviour. Finally, the main perspectives in this field of research are highlighted. Based on the reviewed studies, it becomes plausible to conclude that sleep deprivation induces aggression in several contexts. The opposite relationship, aggressive behavioural phenotype inducing changes in sleep parameters, is applicable in a lower extent. Despite the need for additional investigations into the subject, this review summarized the knowledge that exists on the relationship between sleep and aggressive behaviour, pointing out its neurobiological relevance.Departamento de Psicobiologia Universidade Federal de São PauloDepartment of Physiological Sciences Santa Casa de São Paulo School of Medical SciencesDepartamento de Ciências Biológicas Universidade Estadual PaulistaDepartamento de Ciências Biológicas Universidade Estadual Paulist