Catálogo de publicaciones - revistas

<jats:p> This year brought dismal news about the world's birds: They are vanishing at an alarming rate. Across 25 European countries, about 420 million fewer birds are present today than in 1980, a 20% decrease, especially in the 36 most common species. In North America, <jats:italic>The State of the Birds Report 2014</jats:italic> indicates that over the past 40 years, the numbers of individuals across 33 species are also down by hundreds of millions. Such assessments highlight the urgency of determining the precise causes of these declines. The knowledge gleaned from the Avian Phylogenomics Project, coupled with ecological and population analyses, should provide new insights into the factors that influence bird declines and extinctions. As the project progresses over the next few years, over 60% of tissue samples for the avian analyses will be derived from archived museum collections. In this era of deteriorating natural environments, a pressing challenge is to continue to build scientific collections for future needs. </jats:p>

<jats:p>Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, which predominantly arose because of lineage-specific erosion of repetitive elements, large segmental deletions, and gene loss. Avian genomes furthermore show a remarkably high degree of evolutionary stasis at the levels of nucleotide sequence, gene synteny, and chromosomal structure. Despite this pattern of conservation, we detected many non-neutral evolutionary changes in protein-coding genes and noncoding regions. These analyses reveal that pan-avian genomic diversity covaries with adaptations to different lifestyles and convergent evolution of traits.</jats:p>

<jats:p>To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.</jats:p>