Sandra Walde results 14
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Climate‐induced changes to the ancestral population size of two Patagonian galaxiids: the influence of glacial cyclingNARA Subscribed
Patagonia is one of the few areas in the Southern Hemisphere to have been directly influenced by Quaternary glaciers. In this study, we evaluate the influence that Quaternary glacial ice had on the genetic diversity of two congeneric fish species, the diadromous Galaxias maculatus and the nondiadromous Galaxias platei , using multilocus estimates of effective population size through time. Mid‐Quaternary glaciations had far‐rea...
Invertebrate mesopredators are larger in streams with fishNARA Subscribed
Changes in the distribution of native fishes in response to introduced species and other anthropogenic effectsNARA Subscribed
Aim Globally, one of the major threats to the integrity of native faunas is the loss of biodiversity that can result from the introduction of exotics. Here we document recent changes in the distribution of five common fish species that are linked to introductions in Chile. Location Chile from 28° S to 54° S. Methods We assess the extent of changes in distribution of galaxiid species by comparing their historical and current di...
Migratory species may be especially sensitive to climate change because their lifecycles are affected by dynamic ecological processes operating at global spatial scales. Insight into environmental effects upon en route decisions by migrants can therefore be a critical first step toward assessing their vulnerability to future climatic shifts. We extracted behaviour‐related parameters from a recent formulation of multistate mark...
We employed DNA sequence variation at two mitochondrial (control region, COI) regions from 212 individuals of Galaxias platei (Pisces, Galaxiidae) collected throughout Patagonia (25 lakes/rivers) to examine how Andean orogeny and the climatic cycles throughout the Quaternary affected the genetic diversity and phylogeography of this species. Phylogenetic analyses revealed four deep genealogical lineages which likely represent t...
Climate control on ancestral population dynamics: insight from Patagonian fish phylogeographyNARA Subscribed
Changes in lake and stream habitats during the growth and retreat of Pleistocene glaciers repeatedly altered the spatial distributions and population sizes of the aquatic fauna of the southern Andes. Here, we use variation in mtDNA control region sequences to infer the temporal dynamics of two species of southern Andean fish during the past few million years. At least five important climate events were associated with major de...
Phylogeography of the Percichthyidae (Pisces) in Patagonia: roles of orogeny, glaciation, and volcanismNARA Subscribed
We used molecular evidence to examine the roles that vicariance mechanisms (mountain‐building and drainage changes during the Pleistocene) have played in producing phylogeographical structure within and among South American fish species of the temperate perch family Percichthyidae. The percichthyids include two South American genera, Percichthys and Percilia , each containing several species, all of which are endemic to southe...
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