A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea

<p>Abstract</p> <p>Background</p> <p>Cetacea (dolphins, porpoises, and whales) is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters.</p> <p>Results</p> <p>We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses.</p> <p>Conclusions</p> <p>The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our study fell outside crown Mysticeti and crown Odontoceti, suggesting that these two clades radiated in the late Oligocene or later, contra some recent molecular clock studies. Our trees also imply that many character states shared by river dolphins evolved in their oceanic ancestors, contradicting the hypothesis that these characters are convergent adaptations to fluvial habitats.</p

A Summary of the Developmental Trajectory of Executive Functions from Birth to Adulthood

Executive functions (EFs) refer to cognitive control abilities that can sustain goal-directed behavior within complex contexts or changing contingencies. This cognitive functioning domain involves abilities such as inhibitory control, working memory, cognitive flexibility, attention, and planning and is particularly important for cognitive and socio-emotional advance. Longitudinal design studies have highlighted the relevance of adequate EF development during childhood as a predictor of improved health, higher academic achievements, a better employment status, and a lower incidence of disruptive social conduct, addictions, behavior problems, and psychopathology in adulthood. Hence, understanding EF development and its mediating predictors is a topic of interest for neuroscience. Research work over the past 20 years has produced highly relevant knowledge about specific EF developmental trajectories; however, few studies have compiled these results. This paper will re-examine EF development from early childhood until adulthood to include research reports published in peer-reviewed scientific journals from 2000 to 2019. We will delve into the existence of sensitive periods, growth and decline peaks, common patterns, and gender differences, highlighting unexplored topics and new challenges for future research. Understanding these cognitive development milestones will be a foundational step forward for the design of prevention and EF promotion programs throughout an individual’s vital cycle.Fil: Korzeniowski, Celina Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Ison, Mirta Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Difabio, Hilda Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin