Background The loss of phenotypic characters is a common feature of evolution. Cave
organisms provide excellent models for investigating the underlying patterns and processes …

Cave animals are excellent models to study the general principles of evolution as well as the
mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this …

The fish faunas of continental South and Central America constitute one of the greatest
concentrations of aquatic diversity on Earth, consisting of about 10 percent of all living …

Abstract Background The megadiverse Neotropical freshwater ichthyofauna is the richest in
the world with approximately 6,000 recognized species. Interestingly, they are distributed …

Laboratory studies have demonstrated that a single phenotype can be produced by many
different genotypes; however, in natural systems, it is frequently found that phenotypic …

The family Characidae is the most diverse among Neotropical fishes. Systematics of this
family are mainly based on pre-cladistic papers, and only recently a phylogenetic hypothesis …

Understanding the molecular basis of repeatedly evolved phenotypes can yield key insights
into the evolutionary process. Quantifying gene flow between populations is especially …

The freshwater fish genus Astyanax is one of the most diverse among the Characidae. The
genus is defined by a combination of character states that are widely distributed in …

Background DNA barcoding is one means of establishing a rapid, accurate, and cost-
effective system for the identification of species. It involves the use of short, standard gene …

Patterns of sleep vary widely among species [1–4], but the functional and evolutionary
principles responsible for this diversity remain unknown. The characin fish, Astyanax …