Arne Mooers | Simon Fraser University (original) (raw)

Papers by Arne Mooers

Aim: Recent studies have found that local-scale plots measured through time exhibit marked variat... more Aim: Recent studies have found that local-scale plots measured through time exhibit marked variation in the change in species richness. However, the overall effect often reveals no net change. Most studies thus far have been agnostic about the identities of the species lost/gained, as well as the processes that may lead to these changes. Generalist traits may be crucial in allowing species to colonize new plots or remain resilient in situ, whereas environmental filtering may remove specialists. We test whether plots are changing in species richness, whether they are becoming more similar (i.e. becoming homogenized) through time, as well as whether several generalist traits can predict gains or losses from local plots. Location: Canada Time period: 1945-2015 Major taxa studied: 265 species of butterflies Methods: We measured i. species richness change and ii. pairwise beta diversity across 96 well-sampled 10x10 km plots across Canada between two time periods: 1945-1975 and 1985-2015....

Zoo Biology, 2021

Amphibian health problems of unknown cause limit the success of the growing number of captive bre... more Amphibian health problems of unknown cause limit the success of the growing number of captive breeding programs. Spindly leg syndrome (SLS) is one such disease, where affected individuals with underdeveloped limbs often require euthanization. We experimentally evaluated husbandry-related factors of SLS in a captive population of the critically endangered frog, Andinobates geminisae. SLS has been linked to tadpole nutrition, vitamin B deficiency, water filtration methods, and water quality, but few of these have been experimentally tested. We tested the effects of water filtration method and vitamin supplementation (2017) and the effects of tadpole husbandry protocol intensity (2018) on time to metamorphosis and the occurrence of SLS. We found that vitamin supplementation and reconstituted reverse osmosis filtration of tadpole rearing water significantly reduced SLS prevalence and that reduced tadpole husbandry delayed time to metamorphosis. A fortuitous accident in 2018 resulted in a decrease in the phosphate content of rearing water, which afforded us an additional opportunity to assess the influence of phosphate on calcium sequestration. We found that tadpoles that had more time to sequester calcium for ossification during development had decreased the prevalence of SLS. Taken together, our results suggest that the qualities of the water used to rear tadpoles plays an important role in the development of SLS. Specifically, filtration method, vitamin supplementation, and calcium availability of tadpole rearing water may play important roles. Focused experiments are still needed, but our findings provide important information for amphibian captive rearing programs affected by high SLS prevalence.

Herbivore grazing is an important determinant of plant community assemblages. We used data from a... more Herbivore grazing is an important determinant of plant community assemblages. We used data from a multi-year experimental study in Northern Fennoscandia to analyze the effect of reindeer (Rangifer tarandus) grazing on plant community diversity including its phylogenetic structure. Similar to previous studies on low productivity ecosystems in this region, we found no effect of grazing on plant biodiversity and a transition from dwarf shrubs to graminoids with pulse (i.e. grazed every other year) and press (i.e. grazed every year) grazing. Interestingly, communities with pulse grazing were more phylogenetically dispersed than communities with press grazing and lightly grazed communities. We argue that the indirect effects of reindeer grazing (e.g. interspecific competition and soil nutrient availability) may work in opposition of the direct effects (i.e. physical removal of species) and that the phylogenetic structure of the resulting community will depend upon the relative strengths ...

Journal of Human Evolution, 2016

Animal Conservation, 2015

Proceedings of the Royal Society B: Biological Sciences, 2013

Global climate shifts and ecological flexibility are two major factors that may affect rates of s... more Global climate shifts and ecological flexibility are two major factors that may affect rates of speciation and extinction across clades. Here, we connect past climate to changes in diet and diversification dynamics of ruminant mammals. Using novel versions of Multi-State Speciation and Extinction models, we explore the most likely scenarios for evolutionary transitions among diets in this clade and ask whether ruminant lineages with different feeding styles (browsing, grazing and mixed feeding) underwent differential rates of diversification concomitant with global temperature change. The best model of trait change had transitions from browsers to grazers via mixed feeding, with appreciable rates of transition to and from grazing and mixed feeding. Diversification rates in mixed-feeder and grazer lineages tracked the palaeotemperature curve, exhibiting higher rates during the Miocene thermal maxima. The origination of facultative mixed diet and grazing states may have triggered two ...

Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of U... more Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at

Science, 2013

The News & Analysis stories “Fragile wetland will test Turkey's resolve in protecting bio... more The News & Analysis stories “Fragile wetland will test Turkey's resolve in protecting biodiversity” and “For scientists, protests morph into fight for academic freedom” (J. Bohannon, 26 July, p. [332][1]) deserve to be set in a wider context. Turkey is covered by three global biodiversity

Evolution, 1997

Theories of ecological diversification make predictions about the timing and ordering of characte... more Theories of ecological diversification make predictions about the timing and ordering of character state changes through history. These theories are testable by "reconstructing" ancestor states using phylogenetic trees and measurements of contemporary species. Here we use maximum likelihood to estimate and evaluate the accuracy of ancestor reconstructions. We present likelihoods of discrete ancestor states and derive probability distributions for continuous ancestral traits. The methods are applied to several examples: diets of ancestral Darwin's finches; origin of inquilinism in gall wasps; microhabitat partitioning and body size evolution in scrubwrens; digestive enzyme evolution in artiodactyl mammals; origin of a sexually selected male trait, the sword, in platies and swordtails; and evolution of specialization in Anolis lizards. When changes between discrete character states are rare, the maximumlikelihood results are similar to parsimony estimates. In this case the accuracy of estimates is often high, with the exception of some nodes deep in the tree. If change is frequent then reconstructions are highly uncertain, especially of distant ancestors. Ancestor states for continuous traits are typically highly uncertain. We conclude that measures of uncertainty are useful and should always be provided, despite simplistic assumptions about the probabilistic models that underlie them. If uncertainty is too high, reconstruction should be abandoned in favor of approaches that fit different models of trait evolution to species data and phylogenetic trees, taking into account the range of ancestor states permitted by the data.

Systematic Biology, 1995

Abstract Cladistic tree balance is the extent to which internal nodes on a cladistic tree define ... more Abstract Cladistic tree balance is the extent to which internal nodes on a cladistic tree define clades of equal size. More robust maximum-parsimony trees taken from the literature are more balanced. Simulation studies suggest that a methodological bias is responsible for this correlation because incorrect reconstructions are also likely to be less balanced than the true trees they estimate. Misinformative cladistic characters can be expected to make trees more unbalanced if there is marked variation in their rates of change. This bias may ...

Proceedings of the Royal Society B: Biological Sciences

Alternative prioritization strategies have been proposed to safeguard biodiversity over macroevol... more Alternative prioritization strategies have been proposed to safeguard biodiversity over macroevolutionary time scales. The first prioritizes the most distantly related species—maximizing phylogenetic diversity (PD)—in the hopes of capturing at least some lineages that will successfully diversify into the future. The second prioritizes lineages that are currently speciating, in the hopes that successful lineages will continue to generate species into the future. These contrasting schemes also map onto contrasting predictions about the role of slow diversifiers in the production of biodiversity over palaeontological time scales. We consider the performance of the two schemes across 10 dated species-level palaeo-phylogenetic trees ranging from Foraminifera to dinosaurs. We find that prioritizing PD for conservation generally led to fewer subsequent lineages, while prioritizing diversifiers led to modestly more subsequent diversity, compared with random sets of lineages. Importantly for...

Nature Ecology & Evolution

Originality is a measure of how evolutionarily isolated a species is relative to other members of... more Originality is a measure of how evolutionarily isolated a species is relative to other members of its clade. Recently, originality metrics that explicitly incorporate time have been proposed for conservation prioritization. However, we found that such measures differ qualitatively in how well they capture the total amount of evolution (termed phylogenetic diversity, or PD) represented by a set of species. So, on the tree of all the world’s birds, a pairwise measure based on quadratic entropy captured significantly less PD than did random choice, while a simple tree apportioning measure captured significantly more. We used simulation and simple graph theory to explore the properties of these and other measures with reference to phylogenetic tree shape. Overall, the originality measures do better on more unbalanced trees and on trees with many splits near the present. The rank order of performance was robust across tree shapes, with apportioning measures performing best and node-based...

The extent to which phylogenetic diversity (PD) captures feature diversity (FD) is a topical and ... more The extent to which phylogenetic diversity (PD) captures feature diversity (FD) is a topical and controversial question in biodiversity conservation. In this short paper, we formalise this question and establish a precise mathematical condition for FD (based on discrete characters) to coincide with PD. In this way, we make explicit the two main reasons why the two diversity measures might disagree for given data; namely, the presence of certain patterns of feature evolution and loss, and using temporal branch lengths for PD in settings that may not be appropriate (e.g. due to rapid evolution of certain features over short periods of time). Our paper also explores the relationship between the 'Fair Proportion' index of PD and a simple index of FD (both of which correspond to Shapley values in cooperative game theory). In a second mathematical result, we show that the two indices can take identical values for any phylogenetic tree, provided the branch lengths in the tree are chosen appropriately.

Peer Community In Evolutionary Biology, Oct 3, 2018

Nature ecology & evolution, 2018

In an era of accelerated biodiversity loss and limited conservation resources, systematic priorit... more In an era of accelerated biodiversity loss and limited conservation resources, systematic prioritization of species and places is essential. In terrestrial vertebrates, evolutionary distinctness has been used to identify species and locations that embody the greatest share of evolutionary history. We estimate evolutionary distinctness for a large marine vertebrate radiation on a dated taxon-complete tree for all 1,192 chondrichthyan fishes (sharks, rays and chimaeras) by augmenting a new 610-species molecular phylogeny using taxonomic constraints. Chondrichthyans are by far the most evolutionarily distinct of all major radiations of jawed vertebrates-the average species embodies 26 million years of unique evolutionary history. With this metric, we identify 21 countries with the highest richness, endemism and evolutionary distinctness of threatened species as targets for conservation prioritization. On average, threatened chondrichthyans are more evolutionarily distinct-further motiv...

Homo naledi is a recently discovered species of fossil hominin from South Africa. A considerable ... more Homo naledi is a recently discovered species of fossil hominin from South Africa. A considerable amount is already known about H. naledi but some important questions remain unanswered. Here we report a study that addressed two of them: " Where does H. naledi fit in the hominin evolutionary tree? " and " How old is it? " We used a large supermatrix of craniodental characters for both early and late hominin species and Bayesian phylogenetic techniques to carry out three analyses. First, we performed a dated Bayesian analysis to generate estimates of the evolutionary relationships of fossil hominins including H. naledi. Then we employed Bayes factor tests to compare the strength of support for hypotheses about the relationships of H. naledi suggested by the best-estimate trees. Lastly, we carried out a resampling analysis to assess the accuracy of the age estimate for H. naledi yielded by the dated Bayesian analysis. The analyses strongly supported the hypothesis th...

Molecular phylogenetics and evolution, Jan 30, 2015

The phylogeny of Galliformes (landfowl) has been studied extensively; however, the associated chr... more The phylogeny of Galliformes (landfowl) has been studied extensively; however, the associated chronologies have been criticized recently due to misplaced or misidentified fossil calibrations. As a consequence, it is unclear whether any crown-group lineages arose in the Cretaceous and survived the Cretaceous-Paleogene (K-Pg; 65.5Ma) mass extinction. Using Bayesian phylogenetic inference on an alignment spanning 14,539bp of mitochondrial and nuclear DNA sequence data, four fossil calibrations, and a combination of uncorrelated lognormally distributed relaxed-clock and strict-clock models, we inferred a time-calibrated molecular phylogeny for 225 of the 291 extant Galliform taxa. These analyses suggest that crown Galliformes diversified in the Cretaceous and that three-stem lineages survived the K-Pg mass extinction. Ideally, characterizing the tempo and mode of diversification involves a taxonomically complete phylogenetic hypothesis. We used simple constraint structures to incorporat...