Choosing source populations for conservation reintroductions: lessons from variation in thermal tolerance among populations of the imperilled redside dace

2021 ◽  
Author(s):  
Andy J Turko ◽  
Alexandra T.A. Leclair ◽  
Nicholas E. Mandrak ◽  
D. Andrew R. Drake ◽  
Graham R Scott ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
Selection Process ◽  
The Other ◽  
Source Population ◽  
Thermal Safety ◽  
Safety Margins ◽  
Population Selection ◽  
Acclimation Response ◽  
Research Populations ◽  
Source Populations

Reintroduction is an increasingly common conservation tool to recover populations of imperilled species, but success depends on the suitability of the introduced animals’ phenotype for their new habitat. For fishes, thermal tolerance may be a key trait in urbanized habitats. We compared thermal tolerance (CTmax) among three lineages (western, central, eastern) of imperilled redside dace Clinostomus elongatus. CTmax of eastern adults was 3-4°C lower than the other lineages, but adults of each lineage had similar thermal acclimation responses. In contrast, the acclimation response of juveniles differed by ~80% between the central and western lineages. Using this data, we predicted how each lineage would fare in a hypothetical reintroduction to relatively warm urbanized habitats. Due to the differences in juvenile acclimation responses, predicted thermal safety margins for the central lineage were double those predicted for the western lineage. Overall, we suggest that CTmax is a useful trait to incorporate into the source population selection process. However, there is an urgent need for the establishment of captive experimental research populations of imperilled species to address remaining uncertainties.

scholarly journals Combining superior alleles from two homozygous populations in a cross-fertilizing species

1980 ◽  
Vol 36 (3) ◽  
pp. 277-287 ◽  
Author(s):  
Y. T. Ho ◽  
R. E. Comstock
Keyword(s):  
Real Life ◽  
The Other ◽  
Relative Fitness ◽  
Source Population ◽  
Effective Population ◽  
Complete Dominance ◽  
Selection Limit ◽  
The Difference ◽  
Source Populations ◽  
Foundation Stock

SUMMARYThe issue of incorporating the good alleles from two homozygous populations of a cross-fertilizing species into a single improved population was investigated assuming independent assortment, no epistasis, and either complete dominance (of the favourable or the unfavourable alleles) or additive genes. The selection limit in the foundation stock is a function of the effective population size (N), the proportion (x) contributed by the better source population (P1), the difference in relative fitness between single locus homozygotes and the proportion of loci (that will segregate in the foundation stock) fixed favourably in P1. In real life the last two of these are never known. We therefore focused on the response limits given x = 0·5, 0·75, 0·875 or the optimum value of x (which is a function of the other three parameters). Our general finding was that in situations where N is large enough so that a major portion of the potential can be achieved, the F2 population should be used as the foundation stock when the two source populations do not differ greatly in performance; but when one population performs considerably better than the other, the first backcross (but not second backcross) would be the choice.

Thermal safety margins of plant leaves across biomes under a heatwave

2021 ◽  
pp. 150416
Author(s):  
Kitudom Nawatbhrist ◽  
Fauset Sophie ◽  
Zhou Yingying ◽  
Fan Zexin ◽  
Li Murong ◽  
...  
Keyword(s):  
Thermal Safety ◽  
Plant Leaves ◽  
Safety Margins

British Invasion

2021 ◽  
pp. 107-136
Author(s):  
James C. Nicholson
Keyword(s):  
New York ◽  
Second Generation ◽  
Selection Process ◽  
The Other ◽  
Newspaper Coverage ◽  
Woodrow Wilson ◽  
Industrial Town ◽  
The World ◽  
Jockey Club

Chapter Five discusses the origins of the International Race and the British contestants' transatlantic voyage to America. August Belmont II, chairman of the powerful Jockey Club in New York, convinced Benjamin Irish, the farmer and caterer of relatively modest means who owned Epsom Derby winner Papyrus, to agree to a match race against a to-be-determined American horse. Kentucky Derby champion Zev was the likeliest choice. Admiral Cary T. Grayson, friend and physician to former president Woodrow Wilson, owned the other leading American candidate, My Own. But Hildreth and Sinclair manipulated the selection process. Newspaper coverage of the procedural gamesmanship helped to hype the event. Sportswriters' profiles of the men associated with the English horse -- including jockey Steve Donoghue, who had risen from a rough industrial town to become the most famous rider in the world, and a modest second-generation Newmarket trainer named Basil Jarvis -- spread the ballyhoo nationwide.

scholarly journals Simulation-Based Evaluation of Three Methods for Local Ancestry Deconvolution of Non-model Crop Species Genomes

2019 ◽  
Vol 10 (2) ◽  
pp. 569-579
Author(s):  
Aurélien Cottin ◽  
Benjamin Penaud ◽  
Jean-Christophe Glaszmann ◽  
Nabila Yahiaoui ◽  
Mathieu Gautier
Keyword(s):  
R Package ◽  
Source Population ◽  
Crop Species ◽  
Data Set ◽  
Reproduction Mode ◽  
Local Ancestry ◽  
Ancestry Inference ◽  
Source Populations ◽  
Inference Methods ◽  
Local Ancestry Inference

Hybridizations between species and subspecies represented major steps in the history of many crop species. Such events generally lead to genomes with mosaic patterns of chromosomal segments of various origins that may be assessed by local ancestry inference methods. However, these methods have mainly been developed in the context of human population genetics with implicit assumptions that may not always fit plant models. The purpose of this study was to evaluate the suitability of three state-of-the-art inference methods (SABER, ELAI and WINPOP) for local ancestry inference under scenarios that can be encountered in plant species. For this, we developed an R package to simulate genotyping data under such scenarios. The tested inference methods performed similarly well as far as representatives of source populations were available. As expected, the higher the level of differentiation between ancestral source populations and the lower the number of generations since admixture, the more accurate were the results. Interestingly, the accuracy of the methods was only marginally affected by i) the number of ancestries (up to six tested); ii) the sample design (i.e., unbalanced representation of source populations); and iii) the reproduction mode (e.g., selfing, vegetative propagation). If a source population was not represented in the data set, no bias was observed in inference accuracy for regions originating from represented sources and regions from the missing source were assigned differently depending on the methods. Overall, the selected ancestry inference methods may be used for crop plant analysis if all ancestral sources are known.

Differential drought resistance strategies of co-existing woodland species enduring the long rainless Eastern Mediterranean summer

2019 ◽  
Vol 40 (3) ◽  
pp. 305-320 ◽  
Author(s):  
Päivi J Väänänen ◽  
Yagil Osem ◽  
Shabtai Cohen ◽  
José M Grünzweig
Keyword(s):  
Drought Resistance ◽  
Tree Mortality ◽  
Eastern Mediterranean ◽  
Stomatal Closure ◽  
Woody Species ◽  
The Other ◽  
Severe Drought ◽  
Resistance Strategies ◽  
Safety Margins ◽  
Species Specific

Abstract In anticipation of a drier climate and to project future changes in forest dynamics, it is imperative to understand species-specific differences in drought resistance. The objectives of this study were to form a comprehensive understanding of the drought resistance strategies adopted by Eastern Mediterranean woodland species, and to elaborate specific ecophysiological traits that can explain the observed variation in survival among these species. We examined leaf water potential (𝛹), gas exchange and stem hydraulics during 2–3 years in mature individuals of the key woody species Phillyrea latifolia L., Pistacia lentiscus L. and Quercus calliprinos Webb that co-exist in a dry woodland experiencing ~ 6 rainless summer months. As compared with the other two similarly functioning species, Phillyrea displayed considerably lower 𝛹 (minimum 𝛹 of −8.7 MPa in Phillyrea vs −4.2 MPa in Pistacia and Quercus), lower 𝛹 at stomatal closure and lower leaf turgor loss point (𝛹TLP ), but reduced hydraulic vulnerability and wider safety margins. Notably, Phillyrea allowed 𝛹 to drop below 𝛹TLP under severe drought, whereas the other two species maintained positive turgor. These results indicate that Phillyrea adopted a more anisohydric drought resistance strategy, while Pistacia and Quercus exhibited a more isohydric strategy and probably relied on deeper water reserves. Unlike the two relatively isohydric species, Phillyrea reached complete stomatal closure at the end of the dry summer. Despite assessing a large number of physiological traits, none of them could be directly related to tree mortality. Higher mortality was observed for Quercus than for the other two species, which may result from higher water consumption due to its 2.5–10 times larger crown volume. The observed patterns suggest that similar levels of drought resistance in terms of survival can be achieved via different drought resistance strategies. Conversely, similar resistance strategies in terms of isohydricity can lead to different levels of vulnerability to extreme drought.

Choosing a Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Selection Process ◽  
The Other ◽  
Hard Data ◽  
Methodical Approach ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
First Time ◽  
Scanning Electron

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.

Undue Fear of Inducements in Research in Developing Countries

2009 ◽  
Vol 18 (2) ◽  
pp. 122-129 ◽  
Author(s):  
GARDAR ARNASON ◽  
ANTON VAN NIEKERK
Keyword(s):  
Developing Countries ◽  
Respiratory Distress Syndrome ◽  
Latin American ◽  
Distress Syndrome ◽  
Standard Of Care ◽  
The Other ◽  
Controlled Study ◽  
Born Child ◽  
Research Populations ◽  
Latin American Countries

Prematurely born children who have underdeveloped lungs may suffer a potentially fatal condition called respiratory distress syndrome. A U.S. company developed a drug, called Surfaxin, to treat such poorly functioning lungs. A placebo-controlled study was planned in four Latin American countries (Mexico, Ecuador, Bolivia, and Peru). At the time, in 2001, four treatments were already on the market, although not available to the research populations used in the study. This case is usually discussed as part of the standard of care debate or offered as an example of exploitation. However, what concerns us in this case is rather the choice given to the parents of a prematurely born child under these circumstances: “You can give consent for your child's participation in this study. Half of the babies enrolled will receive sham air and are as likely to die as if they had not enrolled. The other half will receive an active treatment and are more likely to survive.” The parents can vastly increase their baby's chances of survival by participating in the study. Can the consent be voluntary? Do the parents have any meaningful choice?

scholarly journals Effect of antibiotics on bacterial populations: a multi-hierarchical selection process

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 51 ◽  
Author(s):  
José Luis Martínez
Keyword(s):  
Human Body ◽  
Selection Process ◽  
Bacterial Populations ◽  
Bacterial Physiology ◽  
Population Selection ◽  
Human Therapy ◽  
Hierarchical Selection ◽  
Available Information ◽  
Different Levels ◽  
Selection Of

Antibiotics have been widely used for a number of decades for human therapy and farming production. Since a high percentage of antibiotics are discharged from the human or animal body without degradation, this means that different habitats, from the human body to river water or soils, are polluted with antibiotics. In this situation, it is expected that the variable concentration of this type of microbial inhibitor present in different ecosystems may affect the structure and the productivity of the microbiota colonizing such habitats. This effect can occur at different levels, including changes in the overall structure of the population, selection of resistant organisms, or alterations in bacterial physiology. In this review, I discuss the available information on how the presence of antibiotics may alter the microbiota and the consequences of such alterations for human health and for the activity of microbiota from different habitats.

Among- and within-population variability for forage yield and Fusarium resistance in birdsfoot-trefoil

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 761-764 ◽  
Author(s):  
R. R. Hill Jr. ◽  
K. E. Zeiders
Keyword(s):  
Fusarium Oxysporum ◽  
Genetic Model ◽  
Lotus Corniculatus ◽  
Forage Yield ◽  
Birdsfoot Trefoil ◽  
Source Population ◽  
Gene Frequencies ◽  
Breeding For Resistance ◽  
Population Interaction ◽  
Source Populations

Polycross families of birdsfoot-trefoil, Lotus corniculatus L., were evaluated in the greenhouse for number of live plants 120 days after inoculation with Fusarium oxysporum (Schlecht) Snyd. & Hans, and in the field for forage yield and stand scores. The parents of the polycross progenies came from 11 different birdsfoot-trefoil cultivars. The objective of the experiment was to determine relative importance of source population and parents within source population as sources of variability for reaction for F. oxysporum, forage yield, and stand score. Expected values for means of polycross families within source populations and for source populations were expressed in terms of parameters from a previously developed autotetraploid genetic model. All genetic effects were present in the equations, but variation among source populations would be important only if the source populations differed in gene frequencies. Source populations were the only significant source of variation for the number of live plants 120 days after inoculation with F. oxysporum and the stand score. A significant year by source population interaction was observed for total season yield. The correlation between number of live plants in the greenhouse and the stand score was significant. We concluded (i) selection of source population was important when breeding for resistance to F. oxysporum or improved stand but not for total season yield, and (ii) successful breeding for resistance to F. oxysporum would contribute to improved persistence in birdsfoot-trefoil. Key words: Lotus corniculatus L., Fusarium oxysporum, polycross progeny, selection.

scholarly journals Mitochondrial evidence supports a Nearctic origin for the spreading limicolous earthworm Sparganophilus tamesis Benham, 1892 (Clitellata, Sparganophilidae)

2016 ◽  
Vol 85 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Emilia Rota ◽  
Svante Martinsson ◽  
Marco Bartoli ◽  
Anneke Beylich ◽  
Ulfert Graefe ◽  
...  
Keyword(s):  
North America ◽  
The Other ◽  
Distribution Area ◽  
Source Population ◽  
Widespread Species ◽  
Life Data ◽  
Senior Synonym ◽  
Morphological Diagnosis ◽  
European Haplotype ◽  
European Populations

We analysed samples of Sparganophilus taken at the corners of its distribution area in Europe (UK, Germany and Italy). No mitochondrial genetic divergence within and amongst them was found, neither in COI nor in 16S. Further, the COI haplotype was also identical to two sequences from Ontario, Canada in the Barcoding of Life Data System (BOLD) database. Our European COI and 16S sequences showed only minimal differentiation (only 1 or 2 substitutions) from specimens newly collected in Illinois and Washington states (USA), as well as from a COI haplotype from Tennessee (USA) in BOLD. An additional COI haplotype from Illinois (found in BOLD) is 2.1% different from the other haplotypes but clearly belongs to the same lineage of Sparganophilus . This geographically broad but genetically compact group fits the morphological diagnosis of S. tamesis Benham, 1892 as revised by Jamieson (1971) and is seen as evidence that all European populations 1) belong to the same species, 2) derive from a recent introduction, 3) are conspecific with the most widespread species of Sparganophilus in North America, and that 4) S. tamesis is a senior synonym of S. eiseni Smith, 1895. The single European haplotype does not refute the possibility of its spread from a single introduced source population.

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