Common barriers, but temporal dissonance: Genomic tests suggest ecological and paleo‐landscape sieves structure a coastal riverine fish community

Assessments of spatial and temporal congruency across taxa from genetic data provide insights into the extent to which similar processes structure communities. However, for coastal regions that are affected continuously by cyclical sea‐level changes over the Pleistocene, congruent interspecific response will not only depend upon codistributions, but also on similar dispersal histories among taxa. Here, we use SNPs to test for concordant genetic structure among four codistributed taxa of freshwater fishes (Teleostei: Characidae) along the Brazilian Atlantic coastal drainages. Based on population relationships and hierarchical genetic structure analyses, we identify all taxa share the same geographic structure suggesting the fish utilized common passages in the past to move between river basins. In contrast to this strong spatial concordance, model‐based estimates of divergence times indicate that despite common routes for dispersal, these passages were traversed by each of the taxa at different times resulting in varying degrees of genetic differentiation across barriers with most divergences dating to the Upper Pleistocene, even when accounting for divergence with gene flow. Interestingly, when this temporal dissonance is viewed through the lens of the species‐specific ecologies, it suggests that an ecological sieve influenced whether species dispersed readily, with an ecological generalist showing the highest propensity for historical dispersal among the isolated rivers of the Brazilian coast (i.e., the most recent divergence times and frequent gene flow estimated for barriers). We discuss how our findings, and in particular what the temporal dissonance, despite common geographic passages, suggest about past dispersal structuring coastal communities as a function of ecological and paleo‐landscape sieves.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154255/1/mec15357_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154255/2/mec15357.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154255/3/mec15357-sup-0001-Supinfo.pd

Seed Dispersal Anachronisms: Rethinking the Fruits Extinct Megafauna Ate

Background: Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals.10 3 kg), yet these dispersers were extinct in South America 10–15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. Methodology/Principal Findings: We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4–10 cm in diameter with up to five large seeds, and fruits.10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size) with either a single or few (,3 seeds) extremely large seeds or many small seeds (usually.100 seeds). Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. Conclusions/Significance: Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal b

Ações do Projeto “Ações Construtivas do Conhecimento Químico” e Suas Contribuições Pedagógicas na Cidade de Manaus - AM

NESTE TRABALHO SÃO RELATADAS AS CONTRIBUIÇÕES QUE O PROJETO AÇÕES CONSTRUTIVAS DO CONHECIMENTOQUÍMICO NAS ESCOLAS PÚBLICAS TROUXE PARA A VIDA ESCOLAR DOS ESTUDANTES DO ESTADO DO AMAZONAS, SUBRETUDO EM SUA CAPITAL, MANAUS. O PROJETO ACONTECE DESDE OUTUBRO DE 2011, EM 7 ESCOLAS-SEDE, CONTEMPLANDO TODAS AS REGIÕES GEOGRÁFICAS DO MUNICÍPIO. 300 ESTUDANTES, DO PRIMEIRO E SEGUNDO ANO DO ENSINO MÉDIO, ORIUNDOS DE 20 ESCOLAS, SÃO ATENDIDOS PELO PROJETO. AS AULAS SÃO MINISTRADAS POR LICENCIANDOS E BACHARÉIS EM QUÍMICA DA UNIVERSIDADE FEDERAL DO AMAZONAS, E QUE SÃO ORIENTADOS POR SUPERVISORES LICENCIADOS E COM ATUAÇÃO NO ENSINO DE QUÍMICA. O PROJETO AINDA CONTA COM UMA COORDENAÇÃO NACIONAL E OUTRA NO AMAZONAS, COM AULAS SEMANAIS NAS ESCOLAS-SEDE E REUNIÕES DA EQUIPE NA UFAM. AS ATIVIDADES PERMITEM TRABALHAR SIMULTANEAMENTE FORMAÇÃO INICIAL E CONTINUADA DE PROFESSORES DE ENSINO MÉDIO, ALÉM DO APROFUNDAMENTO EM QUÍMICA QUE OS ALUNOS DE ENSINO MÉDIO DE TODAS AS REGIÕES DE MANAUS TÊM ACESSO. NESTE TRABALHO RELATAMOS, SOBRETUDO, O IMPACTO DAS AÇÕES NA FORMAÇÃO INICIAL DOS MONITORE