scholarly journals Human pressures filter out the less resilient demographic strategies in natural populations of plants and animals worldwide

2021 ◽  
Author(s):  
Thomas Merrien ◽  
Katrina Joan Davis ◽  
Pol Capdevila ◽  
Moreno Di Marco ◽  
Roberto Salguero-Gomez
Keyword(s):  
Life History ◽  
Human Activities ◽  
Land Surface ◽  
Urban Areas ◽  
Life History Traits ◽  
Natural Populations ◽  
Life History Strategies ◽  
Vital Rates ◽  
Long Distance ◽  
Animal Populations

The exponential growth that has characterised human societies since the industrial revolution has fundamentally modified our surroundings. Examples include rapid increases in agricultural fields, now accounting for 37% of the land surface, as well as increases in urban areas, projected to triple worldwide by 2030. As such, understanding how species have adapted to and will respond to increasing human pressures is of key importance. Resilience, the ability of an ecological system to resist, recover, and even benefit from disturbances, is a key concept in this regard. Here, using a recently develop comparative demographic framework, we examine how the inherent ability of 921 natural populations of 279 plants and 45 animal species worldwide to respond to disturbances correlates with human settlement size and human activities. We develop a spatially and phylogenetically explicit model parameterised with life history traits and metrics of demographic resilience using the open-access COMPADRE and COMADRE databases, coupled with high-resolution human impact information via the Human Footprint database. We expected: (H1) populations located nearer urban areas to have a greater ability to resist, recover, or benefit from human-related disturbances compared to pristine habitats; (H2) human effects on the responses of animal populations to disturbances to depend on the ability for long-distance mobility; and (H3): human pressures to constrain the repertoire of life history strategies of animal and plant species via their effects on underlying vital rates and life history traits. We find that: (1) urban areas host a limited diversity of strategies that achieve demographic resilience with, on average, more resistant and faster-recovery populations located near human activities than in pristine habitats; (2) species with limited mobility tend to be more strongly affected by human activities than those with long-distance mobility; and (3) human pressures correlate with a limited set of vital rates and life history traits, including the ability to shrink, and reproduce earlier. Our results provide a tangible picture of how, having drastically transformed terrestrial landscapes, humans have shaped the ways animals and plants respond to disturbances.

Sexual size dimorphism and life history traits in an island-mainland system: an overview of the lizard genus Microlophus

2021 ◽  
pp. 1-7
Author(s):  
Ken S. Toyama ◽  
Christopher K. Boccia
Keyword(s):  
Life History ◽  
South America ◽  
Life History Theory ◽  
Life History Traits ◽  
Sexual Size Dimorphism ◽  
Life History Strategies ◽  
Galápagos Islands ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Comprehensive Compilation

Abstract Opposing life history strategies are a common result of the different ecological settings experienced by insular and continental species. Here we present a comprehensive compilation of data on sexual size dimorphism (SSD) and life history traits of Microlophus, a genus of lizards distributed in western South America and the Galápagos Islands, and test for differences between insular and continental species under life history theory expectations. Contrary to our predictions, we found no differences in SSD between localities or evidence that Microlophus follows Rensch’s rule. However, as expected, head dimensions and maturity sizes were significantly larger in insular species while continental species had larger clutches. Our results show that Microlophus exhibits some of the patterns expected from an island-mainland system, but unexplained patterns will only be resolved through future ecological, morphological and behavioural studies integrating both faunas.

scholarly journals The Ecology of Stress: linking life-history traits with physiological control mechanisms in free-living guanacos

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2640 ◽  
Author(s):  
Ramiro J.A. Ovejero Aguilar ◽  
Graciela A. Jahn ◽  
Mauricio Soto-Gamboa ◽  
Andrés J. Novaro ◽  
Pablo Carmanchahi
Keyword(s):  
Life History ◽  
Seasonal Variation ◽  
Reproductive Success ◽  
Hpa Axis ◽  
Life History Traits ◽  
Mating Period ◽  
Entire Study ◽  
Non Invasive ◽  
Animal Populations

BackgroundProviding the context for the evolution of life-history traits, habitat features constrain successful ecological and physiological strategies. In vertebrates, a key response to life’s challenges is the activation of the Stress (HPA) and Gonadal (HPG) axes. Much of the interest in stress ecology is motivated by the desire to understand the physiological mechanisms in which the environment affects fitness. As reported in the literature, several intrinsic and extrinsic factors affect variability in hormone levels. In both social and non-social animals, the frequency and type of interaction with conspecifics, as well as the status in social species, can affect HPA axis activity, resulting in changes in the reproductive success of animals. We predicted that a social environment can affect both guanaco axes by increasing the secretion of testosterone (T) and Glucocorticoid (GCs) in response to individual social interactions and the energetic demands of breeding. Assuming that prolonged elevated levels of GCs over time can be harmful to individuals, it is predicted that the HPA axis suppresses the HPG axis and causes T levels to decrease, as GCs increase.MethodsAll of the data for individuals were collected by non-invasive methods (fecal samples) to address hormonal activities. This is a novel approach in physiological ecology because feces are easily obtained through non-invasive sampling in animal populations.ResultsAs expected, there was a marked adrenal (p-value = .3.4e−12) and gonadal (p-value = 0.002656) response due to seasonal variation inLama guanicoe. No significant differences were found in fecal GCs metabolites between males/females*season for the entire study period (p-value = 0.2839). Despite the seasonal activity variation in the hormonal profiles, our results show a positive correlation (p-value = 1.952e−11, COR = 0.50) between the adrenal and gonadal system. The marked endocrine (r2 = 0.806) and gonad (r2 = 0.7231) response due to seasonal variation in male guanaco individuals highlights the individual’s energetic demands according to life-history strategies. This is a remarkable result because no inhibition was found between the axes as theory suggests. Finally, the dataset was used to build a reactive scope model for guanacos.DiscussionGuanacos cope with the trade-off between sociability and reproductive benefits and costs, by regulating their GCs and T levels on a seasonal basis, suggesting an adaptive role of both axes to different habitat pressures. The results presented here highlight the functional role of stress and gonad axes on a critical phase of a male mammal’s life—the mating period—when all of the resources are at the disposal of the male and must be used to maximize the chances for reproductive success.

scholarly journals Warmer temperatures attenuate the classic offspring number and reproductive investment trade-off in the common lizard, Zootoca vivipara

2016 ◽  
Vol 12 (6) ◽  
pp. 20160101 ◽  
Author(s):  
Alexis Rutschmann ◽  
Donald B. Miles ◽  
Jean Clobert ◽  
Murielle Richard
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
Life History Traits ◽  
Natural Populations ◽  
Trade Off ◽  
Offspring Number ◽  
Common Lizard ◽  
Trade Offs ◽  
Zootoca Vivipara ◽  
The Common

Life-history traits involved in trade-offs are known to vary with environmental conditions. Here, we evaluate the response of the trade-off between ‘offspring number’ versus ‘energy invested per offspring’ to ambient temperature in 11 natural populations of the common lizard, Zootoca vivipara . We provide evidence at both the intra- and interpopulation levels that the trade-off is reduced with an increase in air temperature. If this effect enhances current individual fitness, it may lead to an accelerated pace of life in warmer environments and could ultimately increase adult mortality. In the context of global warming, our results advocate the need for more studies in natural populations to explore interactions between life-history traits' trade-offs and environmental conditions.

Divergent patterns of impact of environmental conditions on life history traits in two populations of a long-distance migratory bird

Oecologia ◽  
2009 ◽  
Vol 159 (4) ◽  
pp. 859-872 ◽  
Author(s):  
Javier Balbontín ◽  
Anders P. Møller ◽  
Ignacio G. Hermosell ◽  
Alfonso Marzal ◽  
Maribel Reviriego ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
Life History Traits ◽  
Migratory Bird ◽  
Long Distance ◽  
Two Populations

Variability of breeding resource partitioning in a lacertid lizard at field scale

2017 ◽  
Vol 67 (2) ◽  
pp. 81-92
Author(s):  
Marta Biaggini ◽  
Claudia Corti
Keyword(s):  
Life History ◽  
Human Activities ◽  
Life History Traits ◽  
Environmental Variability ◽  
Egg Mass ◽  
Life History Variation ◽  
Field Scale ◽  
Starting Point ◽  
Intensively Managed ◽  
The Impact

Human activities cause increasingly deep alterations to natural environments. Yet, the effects on vertebrates with low dispersal capacity are still poorly investigated, especially at field scale. Life history variation represents one means by which species can adapt to a changing environment. Among vertebrates, lizards exhibit a high degree of variation in life-history traits, often associated with environmental variability. We examined the female breeding output ofPodarcissiculus(Lacertidae) inside agricultural habitats, to test whether different cultivation and management influence the life-history traits of this species. Interestingly, we recorded variability of female breeding output at a very fine scale, namely among adjacent vineyards and olive orchards under different management levels. Lizards displayed the lowest breeding effort in the almost unmanaged sites, while clutch mass, relative fecundity and mean egg mass slightly increased in more intensively managed sites. However, in the most intensive cultivations we detected a life-history trade-off, where eggs from larger clutches tended to be relatively smaller than eggs from smaller clutches. This pattern suggests that agriculture can influence lizard reproductive output, partly favouring it in the presence of medium intensity cultivation but causing, in the most intensively managed sites, some environmental constraints that require a peculiar partitioning of the breeding resources. Even though further studies are needed to clarify the mechanisms driving the observed pattern, our results can be considered a starting point for evaluating the analysis of lizard breeding features as a tool to assess the impact of human activities, at least in agricultural environments.

scholarly journals Corticosterone, testosterone and life-history strategies of birds

2010 ◽  
Vol 277 (1697) ◽  
pp. 3203-3212 ◽  
Author(s):  
Michaela Hau ◽  
Robert E. Ricklefs ◽  
Martin Wikelski ◽  
Kelly A. Lee ◽  
Jeffrey D. Brawn
Keyword(s):  
Life History ◽  
Body Mass ◽  
Breeding Season ◽  
Life History Traits ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Tropical Species ◽  
Published Data ◽  
Season Length

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.

Using nitrogen stable isotopes to detect long-distance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)

2009 ◽  
Vol 66 (4) ◽  
pp. 672-682 ◽  
Author(s):  
Adam J. Sepulveda ◽  
Warren T. Colyer ◽  
Winsor H. Lowe ◽  
Mark R. Vinson
Keyword(s):  
Water Quality ◽  
Stable Isotopes ◽  
Life History ◽  
Headwater Streams ◽  
Cutthroat Trout ◽  
Trophic Levels ◽  
Life History Strategies ◽  
Nitrogen Stable Isotopes ◽  
Long Distance ◽  
Oncorhynchus Clarkii

Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a population is critical to these efforts. We tested the application of nitrogen stable isotopes to discern fluvial from resident Bonneville cutthroat trout (BCT; Oncorhynchus clarkii utah ) in a headwater stream. Fluvial BCT migrate from headwater streams with good water quality to mainstem habitats with impaired water quality. Resident BCT remain in headwater streams. We tested two predictions: (i) fluvial BCT have a higher δ15N than residents, and (ii) fluvial BCT δ15N reflects diet and δ15N enrichment characteristics of mainstem habitats. We found that fluvial δ15N was greater than resident δ15N and that δ15N was a better predictor of life history than fish size. Our data also showed that fluvial and resident BCT had high diet overlap in headwater sites and that δ15N of lower trophic levels was greater in mainstem sites than in headwater sites. We conclude that the high δ15N values of fluvial BCT were acquired in mainstem sites.

scholarly journals Switch between Life History Strategies Due to Changes in Glycolytic Enzyme Gene Dosage inSaccharomyces cerevisiae

2010 ◽  
Vol 77 (2) ◽  
pp. 452-459 ◽  
Author(s):  
Shaoxiao Wang ◽  
Aymé Spor ◽  
Thibault Nidelet ◽  
Pierre Montalent ◽  
Christine Dillmann ◽  
...  
Keyword(s):  
Life History ◽  
Cell Size ◽  
Carrying Capacity ◽  
Life History Traits ◽  
Gene Dosage ◽  
Single Gene ◽  
Glycolytic Enzyme ◽  
Life History Strategies ◽  
Glucose Consumption Rate ◽  
Glycolytic Gene

ABSTRACTAdaptation is the process whereby a population or species becomes better fitted to its habitat through modifications of various life history traits which can be positively or negatively correlated. The molecular factors underlying these covariations remain to be elucidated. UsingSaccharomyces cerevisiaeas a model system, we have investigated the effects on life history traits of varying the dosage of genes involved in the transformation of resources into energy. Changing gene dosage for each of three glycolytic enzyme genes (hexokinase 2, phosphoglucose isomerase, and fructose-1,6-bisphosphate aldolase) resulted in variation in enzyme activities, glucose consumption rate, and life history traits (growth rate, carrying capacity, and cell size). However, the range of effects depended on which enzyme was expressed differently. Most interestingly, these changes revealed a genetic trade-off between carrying capacity and cell size, supporting the discovery of two extreme life history strategies already described in yeast populations: the “ants,” which have lower glycolytic gene dosage, take up glucose slowly, and have a small cell size but reach a high carrying capacity, and the “grasshoppers,” which have higher glycolytic gene dosage, consume glucose more rapidly, and allocate it to a larger cell size but reach a lower carrying capacity. These results demonstrate antagonist pleiotropy for glycolytic genes and show that altered dosage of a single gene drives a switch between two life history strategies in yeast.

scholarly journals Environmentally Modulated Repeat Evolution of Polymorphic Arctic Charr Life History Traits

2021 ◽  
Vol 9 ◽  
Author(s):  
Gabrielle Grenier ◽  
Aslak Smalås ◽  
Runar Kjær ◽  
Rune Knudsen
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Growth Parameters ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Local Environment ◽  
Life History Strategies ◽  
Age At Maturity ◽  
First Time ◽  
Sympatric Morphs

Sympatric Arctic charr, Salvelinus alpinus (L. 1758), morphs have flexible but repeated life history strategies tested across five Norwegian lakes. In several Scandinavian polymorphic Arctic charr populations differentiated by their diet and habitat use, a large littoral omnivorous (LO) morph commonly cooccurs with a smaller profundal spawning (PB/PZ) morph. A third, large piscivorous (PP) morph is also known to occur within a portion of Arctic charr populations in the profundal habitat along with the PB/PZ individuals. Life history traits, such as age at maturity, growth, and diet are known to differ among coexisting morphs. Notably, the PP morph was the longest morph with the oldest age at maturity while the PB/PZ morph showed the shortest lengths overall and youngest age with LO morph being intermediate in both traits. Growth parameters differed across all the morphs. When examining growth within morph groups, the LO morph was found to have different growth across all lakes, while similar reproductive investments and different energy acquisition patterns were seen within the PB/PZ and PP morphs. These results suggest repeat evolution in several life history strategies of reproductively isolated Arctic charr sympatric morphs, notably for the first time in the PP morph, while also highlighting the importance of the local environment in modulating life history traits.

scholarly journals Low but significant genetic differentiation underlies biologically meaningful phenotypic divergence in a large Atlantic salmon population

2015 ◽  
Author(s):  
Tutku Aykanat ◽  
Susan E Johnston ◽  
Panu Orell ◽  
Eero Niemelä ◽  
Jaakko Erkinaro ◽  
...  
Keyword(s):  
Life History ◽  
Genetic Differentiation ◽  
Atlantic Salmon ◽  
Genetic Divergence ◽  
Natural Populations ◽  
Structured Populations ◽  
Life History Strategies ◽  
Adaptive Divergence ◽  
Juvenile Growth ◽  
Significant Genetic Differentiation

Despite decades of research assessing the genetic structure of natural populations, the biological meaning of low yet significant genetic divergence often remains unclear due to a lack of associated phenotypic and ecological information. At the same time, structured populations with low genetic divergence and overlapping boundaries can potentially provide excellent models to study adaptation and reproductive isolation in cases where high resolution genetic markers and relevant phenotypic and life history information are available. Here, we combined SNP-based population inference with extensive phenotypic and life history data to identify potential biological mechanisms driving fine scale sub-population differentiation in Atlantic salmon (Salmo salar) from the Teno River, a major salmon river in Europe. Two sympatrically occurring sub-populations had low but significant genetic differentiation (FST = 0.018) and displayed marked differences in the distribution of life history strategies, including variation in juvenile growth rate, age at maturity and size within age classes. Large, late-maturing individuals were virtually absent from one of the two sub-populations and there were significant differences in juvenile growth rates and size-at-age after oceanic migration between individuals in the respective sub-populations. Our findings suggest that different evolutionary processes affect each sub-population and that hybridization and subsequent selection may maintain low genetic differentiation without hindering adaptive divergence.

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