scholarly journals Testing the predictability of morphological evolution in contrasting thermal environments

2019 ◽  
Author(s):  
Natalie Pilakouta ◽  
Joseph L. Humble ◽  
Iain D.C. Hill ◽  
Jessica Arthur ◽  
Ana P.B. Costa ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Gasterosteus Aculeatus ◽  
Morphological Evolution ◽  
Model Organisms ◽  
Shape Variation ◽  
Evolutionary Trajectory ◽  
Thermal Habitat ◽  
Thermal Environments ◽  
Geothermal Activity

ABSTRACTIn light of climate change, the ability to predict evolutionary responses to temperature changes is of central importance for conservation efforts. Prior work has focused on exposing model organisms to different temperatures for just one or a few generations under laboratory conditions. Using a ‘natural experiment’, we show that studying parallel evolution in wild populations from contrasting thermal environments presents a more powerful approach for understanding and predicting responses to climate change. More specifically, we used a unique study system in Iceland, where freshwater populations of threespine sticklebacks (Gasterosteus aculeatus) are found in waters warmed by geothermal activity, adjacent to populations in ambient-temperature water. We used three sympatric and three allopatric warm-cold population pairs to test for repeated patterns of morphological divergence in relation to thermal habitat. We found that thermal habitat explained over 50% of body shape variation: fish from warm habitats had a deeper mid-body, a shorter jaw, and smaller eyes. Our common garden experiment showed that most of these morphological differences between thermal habitats were heritable. Lastly, absence of gene flow seems to facilitate parallel divergence across thermal habitats: all three allopatric population pairs were on a common evolutionary trajectory, whereas sympatric pairs followed different trajectories. Our findings therefore suggest that morphological responses to rising temperatures can be predictable when there is limited gene flow. On the other hand, migration of individuals between different thermal habitats or microhabitats can exaggerate nonparallel evolution and reduce our ability to predict evolutionary responses.

scholarly journals Temperature preference does not evolve in sticklebacks despite multigenerational exposure to elevated temperatures

2019 ◽  
Author(s):  
Natalie Pilakouta ◽  
Shaun S. Killen ◽  
Bjarni K. Kristjánsson ◽  
Skúli Skúlason ◽  
Jan Lindström ◽  
...  
Keyword(s):  
Climate Change ◽  
Gasterosteus Aculeatus ◽  
Elevated Temperatures ◽  
Thermal Environment ◽  
Adaptation To Climate Change ◽  
Evolutionary Potential ◽  
Temperature Preference ◽  
Preferred Temperature ◽  
Geothermal Activity ◽  
Temperature Preferences

ABSTRACTGiven the threat of climate change to biodiversity, a growing number of studies are investigating the potential for organisms to adapt to rising temperatures through changes in their physiology, morphology, and behaviour. Earlier work has predicted that evolutionary adaptation to climate change will be accompanied by a shift in temperature preferences, but empirical evidence for this is limited. Here, we test whether exposure to a warm environment over multiple generations has led to the evolution of higher preferred temperatures in the wild. We have taken advantage of a ‘natural experiment’ in Iceland, where freshwater populations of threespine sticklebacks (Gasterosteus aculeatus) are found in waters warmed by geothermal activity year-round (warm habitats), adjacent to populations in ambient-temperature lakes (cold habitats). We hypothesised that sticklebacks from warm habitats would prefer higher water temperatures than those from cold habitats, but we found no support for this hypothesis. Fish from both warm and cold habitats had an average preferred temperature of 13°C, which is considerably lower than the temperatures experienced by fish in warm habitats for most of the year. Our results therefore challenge the assumption that temperature preferences in ectotherms will readily evolve as a response to climate change. Furthermore, the fact that warm-habitat fish are able to persist at relatively high temperatures despite a lower temperature preference suggests that preferred temperature may be a poor indicator of a population’s evolutionary potential and capacity to adapt to a novel thermal environment.

scholarly journals Safety verification of genetically modified rice morphology, hereditary nature, and quality

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dong Won Jeon ◽  
Jae-Ryoung Park ◽  
Yoon-Hee Jang ◽  
Eun-Gyeong Kim ◽  
Taehun Ryu ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Negative Impact ◽  
Genetically Modified ◽  
Germination Rate ◽  
Future Climate Change ◽  
Yield Reduction ◽  
Drought Tolerant ◽  
Gm Plants ◽  
Gm Rice

Abstract Background The drought environment occurs frequently due to the unpredictable future climate change, and drought has a direct negative impact on crops, such as yield reduction. Drought events are random, frequent, and persistent. Molecular breeding can be used to create drought-tolerant food crops, but the safety of genetically modified (GM) plants must be demonstrated before they can be adopted. In this research, the environmental risk of drought-tolerant GM rice was explored by assessing phenotype and gene flow. Drought resistance genes CaMsrB2 inserted HV8 and HV23 were used as GM rice to analyze the possibility of various agricultural traits and gene flow along with non-GM rice. Results When the traits 1000-grain weight, grain length/width, and yield, were compared with GM rice and non-GM rice, all agricultural traits of GM rice and non-GM rice were the same. In addition, when the germination rate, viviparous germination rate, pulling strength, and bending strength were compared to analyze the possibility of weediness, all characteristic values of GM rice and non-GM rice were the same. Protein, amylose, and moisture, the major nutritional elements of rice, were also the same. Conclusions The results of this research are that GM rice and non-GM rice were the same in all major agricultural traits except for the newly assigned characteristics, and no gene mobility occurred. Therefore, GM rice can be used as a means to solve the food problem in response to the unpredictable era of climate change in the future.

scholarly journals Transcriptomic responses to environmental change in fishes: Insights from RNA sequencing

FACETS ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 610-641 ◽  
Author(s):  
Rebekah A. Oomen ◽  
Jeffrey A. Hutchings
Keyword(s):  
Climate Change ◽  
Rna Sequencing ◽  
Molecular Mechanisms ◽  
Environmental Variability ◽  
Global Climate ◽  
Genetic Research ◽  
Model Organisms ◽  
Rna Seq ◽  
Transcriptomic Responses ◽  
Ecological Importance

The need to better understand how plasticity and evolution affect organismal responses to environmental variability is paramount in the face of global climate change. The potential for using RNA sequencing (RNA-seq) to study complex responses by non-model organisms to the environment is evident in a rapidly growing body of literature. This is particularly true of fishes for which research has been motivated by their ecological importance, socioeconomic value, and increased use as model species for medical and genetic research. Here, we review studies that have used RNA-seq to study transcriptomic responses to continuous abiotic variables to which fishes have likely evolved a response and that are predicted to be affected by climate change (e.g., salinity, temperature, dissolved oxygen concentration, and pH). Field and laboratory experiments demonstrate the potential for individuals to respond plastically to short- and long-term environmental stress and reveal molecular mechanisms underlying developmental and transgenerational plasticity, as well as adaptation to different environmental regimes. We discuss experimental, analytical, and conceptual issues that have arisen from this work and suggest avenues for future study.

Containment strategies for synthetic gene drive organisms and impacts on gene flow.

2021 ◽  
pp. 137-152
Author(s):  
Lei Pei ◽  
Markus Schmidt
Keyword(s):  
Gene Flow ◽  
Fungal Infections ◽  
Basic Research ◽  
Fruit Fly ◽  
Mitigation Strategies ◽  
Synthetic Gene ◽  
Model Organisms ◽  
Gene Drive ◽  
Comprehensive Overview ◽  
Gene Drives

Abstract Gene drives, particularly synthetic gene drives, may help to address some important challenges, by efficiently altering specific sections of DNA in entire populations of wild organisms. Here we review the current development of the synthetic gene drives, especially those RNA-guided synthetic gene drives based on the CRISPR nuclease Cas. Particular focuses are on their possible applications in agriculture (e.g. disease resistance, weed control management), ecosystem conservation (e.g. evasion species control), health (e.g. to combat insect-borne and fungal infections), and for basic research in model organisms (e.g. Saccharomyces, fruit fly, and zebra fish). The physical, chemical, biological, and ecological containment strategies that might help to confine these gene drive-modified organisms are then explored. The gene flow issues, those from gene drive-derived organisms to the environment, are discussed, while possible mitigation strategies for gene drive research are explored. Last but not least, the regulatory context and opinions from key stakeholders (regulators, scientists, and concerned organizations) are reviewed, aiming to provide a more comprehensive overview of the field.

Vulnerability of megapodes (Megapodiidae, Aves) to climate change and related threats

2018 ◽  
Vol 45 (4) ◽  
pp. 396-406 ◽  
Author(s):  
PAUL M. RADLEY ◽  
ROBERT A. DAVIS ◽  
RENÉ W.R.J. DEKKER ◽  
SHAUN W. MOLLOY ◽  
DAVID BLAKE ◽  
...  
Keyword(s):  
Climate Change ◽  
Gene Flow ◽  
Life Histories ◽  
Population Level ◽  
Genetic Connectivity ◽  
Future Research ◽  
Mean Annual Temperature ◽  
Climate Variables ◽  
Microbial Decomposition ◽  
Anthropogenic Habitat

SUMMARYAspects of species life histories may increase their susceptibility to climate change. Owing to their exclusive reliance on environmental sources of heat for incubation, megapodes may be especially vulnerable. We employed a trait-based vulnerability assessment to weigh their exposure to projected climate variables of increasing temperatures, fluctuating rainfall and sea level rise and their biological sensitivity and capacity to adapt. While all 21 species were predicted to experience at least a 2 °C increase in mean annual temperature, 12 to experience a moderate or greater fluctuation in rainfall and 16 to experience rising seas, the most vulnerable megapodes are intrinsically rare and range restricted. Species that employ microbial decomposition for incubation may have an adaptive advantage over those that do not and may be more resilient to climate change. The moderate microclimate necessary for mound incubation, however, may in some areas be threatened by anthropogenic habitat loss exacerbated by warmer and seasonally drier conditions. As with many avian species, little is known about the capacity of megapodes to adapt to a changing climate. We therefore recommend that future research efforts investigate megapode fecundity, gene flow and genetic connectivity at the population level to better determine their adaptive capacity.

scholarly journals Discovery of Putative XX/XY Male Heterogamety in Emydura subglobosa Turtles Exposes a Novel Trajectory of Sex Chromosome Evolution in Emydura

2019 ◽  
Vol 158 (3) ◽  
pp. 160-169 ◽  
Author(s):  
LingSze Lee ◽  
Eugenia E. Montiel ◽  
Nicole Valenzuela
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Molecular Cytogenetics ◽  
Nucleolus Organizer ◽  
Model Organisms ◽  
Comparative Genome Hybridization ◽  
Evolutionary Trajectory ◽  
Genotypic Sex Determination

The discovery of sex chromosome systems in non-model organisms has elicited growing recognition that sex chromosomes evolved via diverse paths that are not fully elucidated. Lineages with labile sex determination, such as turtles, hold critical cues, yet data are skewed toward hide-neck turtles (suborder Cryptodira) and scant for side-neck turtles (suborder Pleurodira). Here, we used classic and molecular cytogenetics to investigate Emydura subglobosa (ESU), an unstudied side-neck turtle with genotypic sex determination from the family Chelidae, where extensive morphological divergence exists among XX/XY systems. Our data represent the first cytogenetic description for ESU. Similarities were found between ESU and E. macquarii (EMA), such as identical chromosome number (2n = 50), a single and dimorphic nucleolus organizer region (NOR) localized in a microchromosome pair (ESU14) of both sexes (detected via FISH of 18S rDNA). Only the larger NOR is active (detected by silver staining). As in EMA, comparative genome hybridization revealed putative macro XX/XY chromosomes in ESU (the 4th largest pair). Our comparative analyses and revaluation of previous data strongly support the hypothesis that Emydura's XX/XY system evolved via fusion of an ancestral micro-Y (retained by Chelodina longicollis) onto a macro-autosome. This evolutionary trajectory differs from the purported independent evolution of XX/XY from separate ancestral autosomes in Chelodina and Emydura that was previously reported. Our data permit dating this Y-autosome fusion to at least the split of Emydura around 45 Mya and add critical information about the evolution of the remarkable diversity of sex-determining mechanisms in turtles, reptiles, and vertebrates.

scholarly journals Are model organisms representative for climate change research? Testing thermal tolerance in wild and laboratory zebrafish populations

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Rachael Morgan ◽  
Josefin Sundin ◽  
Mette H Finnøen ◽  
Gunnar Dresler ◽  
Marc Martínez Vendrell ◽  
...  
Keyword(s):  
Climate Change ◽  
Thermal Tolerance ◽  
Thermal Environment ◽  
Model Organisms ◽  
Acclimation Temperature ◽  
Wild Populations ◽  
Climate Change Research ◽  
Genetic Traits ◽  
In The Wild ◽  
Laboratory Acclimation

Abstract Model organisms can be useful for studying climate change impacts, but it is unclear whether domestication to laboratory conditions has altered their thermal tolerance and therefore how representative of wild populations they are. Zebrafish in the wild live in fluctuating thermal environments that potentially reach harmful temperatures. In the laboratory, zebrafish have gone through four decades of domestication and adaptation to stable optimal temperatures with few thermal extremes. If maintaining thermal tolerance is costly or if genetic traits promoting laboratory fitness at optimal temperature differ from genetic traits for high thermal tolerance, the thermal tolerance of laboratory zebrafish could be hypothesized to be lower than that of wild zebrafish. Furthermore, very little is known about the thermal environment of wild zebrafish and how close to their thermal limits they live. Here, we compared the acute upper thermal tolerance (critical thermal maxima; CTmax) of wild zebrafish measured on-site in West Bengal, India, to zebrafish at three laboratory acclimation/domestication levels: wild-caught, F1 generation wild-caught and domesticated laboratory AB-WT line. We found that in the wild, CTmax increased with increasing site temperature. Yet at the warmest site, zebrafish lived very close to their thermal limit, suggesting that they may currently encounter lethal temperatures. In the laboratory, acclimation temperature appeared to have a stronger effect on CTmax than it did in the wild. The fish in the wild also had a 0.85–1.01°C lower CTmax compared to all laboratory populations. This difference between laboratory-held and wild populations shows that environmental conditions can affect zebrafish’s thermal tolerance. However, there was no difference in CTmax between the laboratory-held populations regardless of the domestication duration. This suggests that thermal tolerance is maintained during domestication and highlights that experiments using domesticated laboratory-reared model species can be appropriate for addressing certain questions on thermal tolerance and global warming impacts.

Multivariate analysis of geographic covariance between phenotypes and environments in the threespine stickleback, Gasterosteus aculeatus, from the Cook Inlet area, Alaska

1994 ◽  
Vol 72 (8) ◽  
pp. 1497-1509 ◽  
Author(s):  
J. F. Bourgeois ◽  
D. M. Blouw ◽  
J. P. Koenings ◽  
M. A. Bell
Keyword(s):  
Gene Flow ◽  
Environmental Factors ◽  
Lake Water ◽  
Gasterosteus Aculeatus ◽  
Ion Composition ◽  
Cook Inlet ◽  
Lake Productivity ◽  
Low Concentrations ◽  
Calcium Magnesium ◽  
Reactive Phosphorus

Widely distributed freshwater populations of Gasterosteus aculeatus exhibit reduction in the bones of the pelvis and the numbers of lateral plates and dorsal spines. We investigated the relationship between skeletal reduction and the characteristics of the environments in which it occurs. A combination of environmental factors, including environmental ion composition – lake productivity, geographic position, opportunity for gene flow, and the presence of other fishes, is associated with skeletal reduction. The principal correlates of reduction in all skeletal traits are low concentrations of calcium, magnesium, silicon, H+, and reactive phosphorus. We hypothesize that the ion composition of lake water is the main selective agent promoting skeletal reduction in sticklebacks in the Cook Inlet area, Alaska, and that other fishes and local gene flow may modify its extent. Our results show that a suite of skeletal traits responds in common to the interacting effects of at least three environmental factors (ion composition of lake water, presence of other fishes, local gene flow), and they emphasize that unitary explanations of the evolution of skeletal reduction are unlikely to be adequate.

Sign in / Sign up

Export Citation Format

Share Document