Data from: Ecological speciation of bacteriophage lambda in allopatry and sympatry

Understanding the conditions that allow speciation to occur is difficult because most research has focused on either long-lived organisms or asexual microorganisms. We propagated bacteriophage λ, a virus with rapid generations and frequent recombination, on two Escherichia coli host genotypes that expressed either the LamB or OmpF receptor. When supplied with either single host (allopatry), λ improved its binding to the available receptor while losing its ability to use the alternative. When evolving on both hosts together (sympatry), the viruses split into two lineages with divergent receptor preferences. Although the level of divergence varied among replicates, some lineages evolved reproductive isolation via genetic incompatibilities. This outcome indicates that, under suitable conditions, allopatric and sympatric speciation can occur with similar ease

Ecological speciation of bacteriophage lambda in allopatry and sympatry

A laboratory model of viral speciation New species arise through the evolution of barriers to reproduction. This process is well understood where the emerging species are spatially isolated from one another. But the process of sympatric speciation—where the diverging species co-occur—is more enigmatic. Bacterial viruses make good models for addressing such questions because of their rapid generation times. Meyer et al. took bacteriophage λ and grew it on a mix of two strains of Escherichia coli. The virus duly split its host preferences into lineages with differing affinity for their respective E. coli hosts. In some experiments, the phages diverged to the extent that they became reproductively restricted to one strain of E. coli , even when the other was present. Science , this issue p. 1301 </jats:p

Meyer Science 2016 Fig S1

Data collected for results shown in figure S1, see notes within the file and the manuscript for further guidance

Rat ultrasonic vocalizations demonstrate that the motivation to contextually reinstate cocaine-seeking behavior does not necessarily involve a hedonic response

Human self-reports often indicate that changes in mood are a major contributor to drug relapse. Still, arguments have been made that instances of drug-seeking following abstinence in animal models (i.e. relapse/reinstatement) may be outside of hedonic control. Therefore, the present study utilized ultrasonic vocalizations in the rat in order to evaluate affect during cocaine self-administration (S-A) and contextual reinstatement of cocaine-seeking in a pre-clinical model of drug relapse (abstinence-reinstatement model). Results show that while subjects effectively reinstated drug-seeking (lever pressing) following 30 days of abstinence, and spontaneously recovered/reinstated drug seeking following 60 days of abstinence, ultrasonic vocalizations did not increase over baseline levels during either reinstatement session. These results are consistent with previous results from our laboratory and current theories of addiction suggesting that cues that are weakly-associated with drug consumption can motivate drug-seeking behavior that is outside of hedonic processing

UPWARD TERMINATION OF COMPLEX LARGE-SCALE INTERVALS OF SOFT-SEDIMENT DEFORMATION (SSD) IN THE NAVAJO SANDSTONE: DOES EROSIONAL TRUNCATION OCCUR BEFORE OR AFTER DEFORMATION?

Data collected for results shown in figure 3, see notes within the file and the manuscript for further guidance