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Data from: Disentangling invasion processes in a dynamic shipping - boating network
Lacoursière-Roussel, Anaïs; McKindsey, Christopher W.; Bock, Dan G.; Cristescu, Melania E.; Guichard, Frédéric; Girard, Philippe; Legendre, Pierre — 2012-09-25 The relative importance of multiple vectors to the initial establishment, spread, and population dynamics of invasive species remains poorly understood. This study used molecular methods to clarify the roles of commercial shipping and recreational boating in the invasion by the cosmopolitan tunicate, Botryllus schlosseri. We evaluated i) single vs. multiple introduction scenarios, ii) the relative importance of shipping and boating to primary introductions, iii) the interaction between these vectors for spread (i.e., the presence of a shipping-boating network), and iv) the role of boating in determining population similarity. Tunicates were sampled from 26 populations along the Nova Scotia, Canada, coast that were exposed to either shipping (i.e., ports), or boating (i.e., marinas) activities. A total of 874 individuals (~30 per population) from 5 ports and 21 marinas was collected and analyzed using both mitochondrial cytochrome c oxidase subunit I gene (COI) and 10 nuclear microsatellite markers. The geographical location of multiple hotspot populations indicates that multiple invasions have occurred in Nova Scotia. A loss of genetic diversity from port to marina populations suggests a stronger influence of ships than recreational boats on primary coastal introductions. Population similarity analysis reveals a clear dependence of marina populations on those that had been previously established in ports and connectivity due to a boating network better explains patterns in population similarities than does natural spread. We conclude that frequent primary introductions arise by ships and that secondary spread occurs gradually thereafter around individual ports, facilitated by recreational boating.
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Data from: The availability of research data declines rapidly with article age
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Vines, Timothy H.; Albert, Arianne Y. K.; Andrew, Rose L.; Débarre, Florence; Bock, Dan G.; Franklin, Michelle T.; Gilbert, Kimberly J.; Moore, Jean-Sébastien; Renaut, Sébastien; Rennison, Diana J. — 2014-11-05 Policies ensuring that research data are available on public archives are increasingly being implemented at the government, funding agency, and journal level. These policies are predicated on the idea that authors are poor stewards of their data, particularly over the long term, and indeed many studies have found that authors are often unable or unwilling to share their data. However, there are no systematic estimates of how the availability of research data changes with time since publication. We therefore requested datasets from a relatively homogenous set of 516 articles published between 2 and 22 years ago, and found that availability of the data was strongly affected by article age. For papers where the authors gave the status of their data, the odds of a dataset being extant fell by 17% per year. In addition, the odds that we could find a working email address for the first, last or corresponding author fell by 7% per year. Our results reinforce the notion that, in the long term, research data cannot be reliably preserved by individual researchers, and further demonstrate the urgent need for policies mandating data sharing via public archives.
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Data from: Mandated data archiving greatly improves access to research data
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Vines, Timothy H.; Andrew, Rose L.; Bock, Dan G.; Franklin, Michelle T.; Gilbert, Kimberly J.; Kane, Nolan C.; Moore, Jean-Sébastien; Moyers, Brook T.; Renaut, Sébastien; Rennison, Diana J.; Veen, Thor; Yeaman, Sam — 2013-01-04 The data underlying scientific papers should be accessible to researchers both now and in the future, but how best can we ensure that these data are available? Here we examine the effectiveness of four approaches to data archiving: no stated archiving policy, recommending (but not requiring) archiving, and two versions of mandating data deposition at acceptance. We control for differences between data types by trying to obtain data from papers that use a single, widespread population genetic analysis, STRUCTURE. At one extreme, we found that mandated data archiving policies that require the inclusion of a data availability statement in the manuscript improve the odds of finding the data online almost 1000-fold compared to having no policy. However, archiving rates at journals with less stringent policies were only very slightly higher than those with no policy at all. We also assessed the effectiveness of asking for data directly from authors and obtained over half of the requested datasets, albeit with ∼8 d delay and some disagreement with authors. Given the long-term benefits of data accessibility to the academic community, we believe that journal-based mandatory data archiving policies and mandatory data availability statements should be more widely adopted.
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Data from: Evolution of invasiveness by genetic accommodation
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Bock, Dan G.; Kantar, Michael B.; Caseys, Celine; Matthey-Doret, Remi; Rieseberg, Loren H. — 2019-03-16 Invasion success of species introduced to novel environments may be facilitated by adaptive evolution and by phenotypic plasticity. Here we investigate the independent and joint contribution of both mechanisms as drivers of invasiveness in the perennial sunflower Helianthus tuberosus. We show that invasive genotypes have multiple origins, and that invasive spread was facilitated by the repeated evolution of extreme values in a single trait, clonality. In line with genetic accommodation theory, we establish that this evolutionary transition occurred by refining a preexisting plastic response of clonality to water availability. Further, we demonstrate that under the non-drought conditions typically experienced by this plant in its introduced range, invasive spread is mediated by hybrid vigor and/or two major additive-effect loci, and that these mechanisms are complementary. Thus, in H. tuberosus, evolution of invasiveness was facilitated by phenotypic plasticity, and involved the use of multiple genetic solutions to achieve the same invasiveness trait.
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Data from: Speciation with gene flow and the genetics of habitat transitions
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Cristescu, Melania E.; Constantin, Anna; Bock, Dan G.; Cáceres, Carla E.; Crease, Teresa J. — 2011-12-07 Whether speciation can advance to completion in the face of initially high levels of gene flow is a very controversial topic in evolutionary biology. Extensive gene exchange is generally considered to homogenize populations and counteract divergence. Moreover, the role of introgressive hybridization in evolution remains largely unexplored in animals, particularly in freshwater zooplankton in which allopatric speciation is considered to be the norm. Our work investigates the genetic structure of two young ecological species: the pond species, Daphnia pulex and the lake species, Daphnia pulicaria. Phylogenetic and population genetics analyses were conducted on mitochondrial NADH dehydrogenase 5 (ND5) gene, the nuclear Lactate dehydrogenase (Ldh) gene, and 21 nuclear microsatellite markers in 416 individuals from habitats with various degrees of permanence. The strong and consistent phylogenetic discordance between nuclear and mitochondrial markers suggests a complex evolutionary history of multiple independent habitat transition events that involved hybridization and introgression between lake and pond Daphnia. On the other hand, the low level of contemporary gene flow between adjacent populations indicates the presence of effective habitat isolating barriers. The Daphnia system provides strong evidence for a divergence-with-gene flow speciation model that involves multiple habitat transition events.

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(Author: Bock, Dan G.)

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