Giacomo Bernardi

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Nucleotide sequences of all genomes are subject to compositional constraints that (1) affect, to about the same extent, both coding and noncoding sequences; (2) influence not only the structure and function of the genome, but also those of transcripts and proteins; (3) are the result of environmental pressures; and (4) largely control the fixation of(More)
National Center for Ecological Analysis and Synthesis, University of California, 735 State St., 300, Santa Barbara, CA, 93101, USA, Departamento de Ecologia e Zoologia, Lab. de Biogeografia e Macroecologia Marinha, Universidade Federal de Santa Catarina, Florianópolis, SC 88010-970, Brazil, Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe,(More)
  • G Bernardi
  • Evolution; international journal of organic…
  • 2000
Marine species generally show high dispersal capabilities, which should be accompanied by high levels of gene flow and low speciation rates. However, studies that focused on the relationship between dispersal and gene flow in marine fishes have been inconclusive. This study focuses on the black surfperch, Embiotoca jacksoni, a temperate reef fish that lacks(More)
Population disjunctions, as a first step toward complete allopatry, present an interesting situation to study incipient speciation. The geological formation of the Baja California Peninsula currently divides 19 species of fish into disjunct populations that are found on its Pacific Coast and in the northern part of the Gulf of California (also called the(More)
Relationships based on mtDNA and nDNA sequences were used to assess effects of two major geographic barriers (the >30 myo Atlantic ocean and the approximately 11 myo Amazon-Orinoco outflow) on speciation among Atlantic parrotfishes (Sparisoma and Nicholsina). Allopatric distributions of sister taxa implicate isolating actions of both barriers in all recent(More)
The GC levels of codon third positions from 49 genomes coveering a wide phylogenetic range are linearly correlated with the GC levels of the corresponding genomes. Three different relationships have been found: one for prokaryotes and viruses, one for lower eukaryotes, and one for vertebrates. All points not fitting the first relationship can be brought(More)
Many rural and remote communities around the world see themselves on the wrong side of the digital divide. In particular, there is evidence to suggest that there is a growing digital divide between urban and rural areas in terms of broadband Internet access with people living in rural areas having fewer choices and pay higher prices for slower speeds. This(More)
Population disjunctions have been proposed to play an important role in speciation processes. In this study, we have examined the possible role of the Pacific Ocean-Sea of Cortez disjunction as a contributing factor to cryptic speciation in a reef fish, the opaleye, Girella nigricans. Mitochondrial control region (D-loop) sequences (380 bp) of 117(More)
The evolution of vertebrate genomes can be investigated by analyzing their regional compositional patterns, namely the compositional distributions of large DNA fragments (in the 30–100-kb size range), of coding sequences, and of their different codon positions. This approach has shown the existence of two evolutionary modes. In the conservative mode,(More)
We have investigated the correlation between chromosome banding and compositional compartmentalization of the genome in three selected fish species, Anguilla anguilla (Anguilliformes), Epinephelus guttatus (Perciformes), and Labeo bicolor (Cypriniformes). These species were selected because they provided a spectrum of such compartmentalizations. Indeed, the(More)