scholarly journals Bigger Is Fitter? Quantitative Genetic Decomposition of Selection Reveals an Adaptive Evolutionary Decline of Body Mass in a Wild Rodent Population

2016 ◽  
Author(s):  
Bonnet Timothée ◽  
Wandeler Peter ◽  
Camenisch Glauco ◽  
Postma Erik
Keyword(s):  
Body Mass ◽  
Adaptive Evolution ◽  
Selective Pressure ◽  
Natural Populations ◽  
Positive Association ◽  
Evolutionary Change ◽  
Wild Rodent ◽  
Rodent Population ◽  
Quantitative Genetic ◽  
Evolutionary Response

AbstractIn natural populations, quantitative trait dynamics often do not appear to follow evolutionary predictions: Despite abundant examples of natural selection acting on heritable traits, conclusive evidence for contemporary adaptive evolution remains rare for wild vertebrate populations, and phenotypic stasis seems to be the norm. This so-called ‘stasis paradox’ highlights our inability to predict evolutionary change, which is especially concerning within the context of rapid anthropogenic environmental change. While the causes underlying the stasis paradox are hotly debated, comprehensive attempts aiming at a resolution are lacking. Here we apply a quantitative genetic framework to individual-based long-term data for a wild rodent population and show that despite a positive association between body mass and fitness, there has been a genetic change towards lower body mass. The latter represents an adaptive response to viability selection favouring juveniles growing up to become relatively small adults, i.e. with a low potential adult mass, which presumably complete their development earlier. This selection is particularly strong towards the end of the snow-free season, and it has intensified in recent years, coinciding which a change in snowfall patterns. Importantly, neither the negative evolutionary change, nor the selective pressures that drive it, are apparent on the phenotypic level, where they are masked by phenotypic plasticity and a non-causal (i.e. non-genetic) positive association between body mass and fitness, respectively. Estimating selection at the genetic level thereby enabled us to uncover adaptive evolution in action, and to identify the corresponding phenotypic selective pressure. We thereby demonstrate that natural populations can show a rapid and adaptive evolutionary response to a novel selective pressure, and that explicitly (quantitative) genetic models are able to provide us with an understanding of the causes and consequences of selection that is superior to purely phenotypic estimates of selection and evolutionary change.

scholarly journals Phenotypic plasticity and adaptive evolution contribute to advancing flowering phenology in response to climate change

2012 ◽  
Vol 279 (1743) ◽  
pp. 3843-3852 ◽  
Author(s):  
Jill T. Anderson ◽  
David W. Inouye ◽  
Amy M. McKinney ◽  
Robert I. Colautti ◽  
Tom Mitchell-Olds
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Adaptive Evolution ◽  
Field Experiments ◽  
Flowering Phenology ◽  
Directional Selection ◽  
Major Life ◽  
Quantitative Genetic ◽  
Evolutionary Response

Anthropogenic climate change has already altered the timing of major life-history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie rapid phenological shifts in response to climate change, but their relative contributions are poorly understood. Here, we combine a continuous 38 year field survey with quantitative genetic field experiments to assess adaptation in the context of climate change. We focused on Boechera stricta (Brassicaeae), a mustard native to the US Rocky Mountains. Flowering phenology advanced significantly from 1973 to 2011, and was strongly associated with warmer temperatures and earlier snowmelt dates. Strong directional selection favoured earlier flowering in contemporary environments (2010–2011). Climate change could drive this directional selection, and promote even earlier flowering as temperatures continue to increase. Our quantitative genetic analyses predict a response to selection of 0.2 to 0.5 days acceleration in flowering per generation, which could account for more than 20 per cent of the phenological change observed in the long-term dataset. However, the strength of directional selection and the predicted evolutionary response are likely much greater now than even 30 years ago because of rapidly changing climatic conditions. We predict that adaptation will likely be necessary for long-term in situ persistence in the context of climate change.

scholarly journals Plasticity-led evolution: evaluating the key prediction of frequency-dependent adaptation

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182754 ◽  
Author(s):  
Nicholas A. Levis ◽  
David W. Pfennig
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Adaptive Evolution ◽  
Natural Populations ◽  
Evolutionary Change ◽  
Adaptive Refinement ◽  
Fairy Shrimp ◽  
Extreme Form ◽  
Spadefoot Toad ◽  
Evolution By Natural Selection

Plasticity-led evolution occurs when a change in the environment triggers a change in phenotype via phenotypic plasticity, and this pre-existing plasticity is subsequently refined by selection into an adaptive phenotype. A critical, but largely untested prediction of plasticity-led evolution (and evolution by natural selection generally) is that the rate and magnitude of evolutionary change should be positively associated with a phenotype's frequency of expression in a population. Essentially, the more often a phenotype is expressed and exposed to selection, the greater its opportunity for adaptive refinement. We tested this prediction by competing against each other spadefoot toad tadpoles from different natural populations that vary in how frequently they express a novel, environmentally induced carnivore ecomorph. As expected, laboratory-reared tadpoles whose parents were derived from populations that express the carnivore ecomorph more frequently were superior competitors for the resource for which this ecomorph is specialized—fairy shrimp. These tadpoles were better at using this resource both because they were more efficient at capturing and consuming shrimp and because they produced more exaggerated carnivore traits. Moreover, they exhibited these more carnivore-like features even without experiencing the inducing cue, suggesting that this ecomorph has undergone an extreme form of plasticity-led evolution—genetic assimilation. Thus, our findings provide evidence that the frequency of trait expression drives the magnitude of adaptive refinement, thereby validating a key prediction of plasticity-led evolution specifically and adaptive evolution generally.

scholarly journals Metabolic syndrome in patients with prostate cancer

2008 ◽  
Vol 126 (5) ◽  
pp. 274-278 ◽  
Author(s):  
Iúri Amorim de Santana ◽  
Gustavo Souza Moura ◽  
Nivaldo Farias Vieira ◽  
Rosana Cipolotti
Keyword(s):  
Prostate Cancer ◽  
Metabolic Syndrome ◽  
Body Mass ◽  
Specific Antigen ◽  
Density Lipoprotein ◽  
Positive Association ◽  
Serum Glucose ◽  
Anthropometric Parameters ◽  
Cross Sectional ◽  
Waist To Hip Ratio

CONTEXT AND OBJECTIVE: Prostate cancer (PCa) is the second most common cancer among men in Brazil. Recently, several studies have hypothesized a relationship between PCa and metabolic syndrome (MS). The aim here was to identify an association between MS and PCa. DESIGN AND SETTING: Cross-sectional study, Fundação de Beneficência Hospital de Cirurgia (FBHC) and Universidade Federal de Sergipe. METHODS: Laboratory and anthropometric parameters were compared between PCa patients (n = 16) and controls (n = 16). RESULTS: The PCa patients showed significantly greater frequency of MS than did the controls (p = 0.034). Serum glucose was higher and high-density lipoprotein-cholesterol was lower than in the controls, although without significant differences. There were significant differences in blood pressure (p = 0.029) and waist-to-hip ratio (p = 0.004). Pearson linear correlation showed a positive association between waist-to-hip ratio and prostate specific antigen (r = 0.584 and p = 0.028). Comparing subgroups with and without MS among the PCa patients, significant differences (p < 0.05) in weight, height, body mass index, hip circumference and lean body mass were observed, thus showing higher central obesity in those with MS. The serum glucose values were also higher in MS patients (p = 0.006), thus demonstrating that insulin resistance has a role in MS physiopathology. CONCLUSIONS: Our study suggests that MS may exert an influence on the development of PCa. However, it would be necessary to expand the investigation field with larger sample sizes and cohorts studied, to test the hypothesis generated in this study.

Serum leptin levels and energy expenditure in normal weight women

1998 ◽  
Vol 76 (2) ◽  
pp. 237-241 ◽  
Author(s):  
L J Martin ◽  
PJH Jones ◽  
R V Considine ◽  
W Su ◽  
N F Boyd ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Food Intake ◽  
Energy Expenditure ◽  
Body Mass ◽  
Body Fat ◽  
Positive Association ◽  
Normal Weight ◽  
Serum Leptin ◽  
Percentage Body Fat ◽  
Healthy Humans

To investigate whether circulating leptin levels are associated with energy expenditure in healthy humans, doubly labeled water energy measurements and food intake assessment were carried out in 27 women (mean age, 48.6 years; weight, 61.9 kg; body mass index, 23.2). Energy expenditure was determined over 13 days. Food intake was measured by 7-day food records. Leptin was measured by radioimmunoassay. Leptin level was strongly associated with percentage body fat (r = 0.59; p < 0.001), fat mass (r = 0.60; p < 0.001), and body mass index (r = 0.41; p = 0.03), but no correlation was observed with energy expenditure (r = 0.02; p = 0.93). After controlling for percentage body fat, a positive association of leptin level with energy expenditure of marginal significance (p = 0.06) was observed. There were no significant univariate associations of age, physical activity, lean body mass, height, or dietary variables with leptin level. When controlling for body fat, a significant positive correlation was observed for percent energy from carbohydrate and negative correlations with dietary fat and alcohol intake. These findings confirm previous associations between leptin and body fat content and suggest a relationship between serum leptin and energy expenditure level in healthy humans.Key words: leptin, energy expenditure, body composition, diet.

scholarly journals Body mass index and lifetime healthcare utilization

2019 ◽  
Author(s):  
Christina Hansen Edwards ◽  
Eline Aas ◽  
Jonas Minet Kinge
Keyword(s):  
Primary Care ◽  
Body Mass Index ◽  
Healthcare Utilization ◽  
Body Mass ◽  
Secondary Care ◽  
Positive Association ◽  
Normal Weight ◽  
Overweight And Obesity ◽  
Care Utilization ◽  
Global Public Health

Abstract Background: Overweight and obesity is a major global public health challenge, and understanding the implications for healthcare systems is essential for policy planning. Past studies have typically found positive associations between obesity and healthcare utilization, but these studies have not taken into consideration that obesity is also associated with early mortality. We examined associations between body mass index (BMI, reported as kg/m2) and healthcare utilization with and without taking BMI-specific survival into consideration. Methods: We used nationally representative data on 33 882 adults collected between 2002 and 2015. We computed BMI- and age-specific primary and secondary care utilization and multiplied the estimated values with gender-, age-, and BMI-specific probabilities of surviving to each age. Then, we summed the average BMI-specific utilization between 18 and 85 years. Results: During a survival-adjusted lifetime, males with normal weight (BMI: 18.5–24.9) had, on average, 167 primary care, and 77 secondary care contacts. In comparison, males with overweight (BMI: 25.0–29.9), category I obesity (BMI: 30.0–34.9), and category II/III obesity (BMI ≥35.0) had 11%, 41%, and 102% more primary care, and 14%, 29%, and 78% more secondary care contacts, respectively. Females with normal weight had, on average, 210 primary care contacts and 91 secondary care contacts. Females with overweight, category I obesity, and category II/III obesity had 20%, 34%, and 81% more primary care contacts, and 26%, 16%, and 16% more secondary care contacts, respectively. Conclusion: The positive association between BMI and healthcare utilization was reduced, but not offset, when BMI-specific survival was taken into consideration. Our findings underpin previous research and suggest that interventions to offset the increasing prevalence of overweight, and especially obesity, are warranted.

scholarly journals Socioeconomic Status, Institutional Power, and Body Mass Index among Chinese Adults

2021 ◽  
Vol 18 (20) ◽  
pp. 10620
Author(s):  
Weidong Li ◽  
Shuzhuo Li ◽  
Marcus W. Feldman
Keyword(s):  
Body Mass Index ◽  
Socioeconomic Status ◽  
Body Mass ◽  
Positive Association ◽  
Chinese Adults ◽  
State Institutions ◽  
Force Dynamics ◽  
Institutional Power ◽  
Negative Effect ◽  
Positive Effect

Despite the vast literature on the socioeconomic status (SES) gradient of obesity among adult people, no study has investigated the relationship between institutional power and body mass index. Using national survey data from the “China Labor-force Dynamics Survey 2016” (CLDS 2016), multistage cluster-stratified probability proportional to size (PPS) sampling was employed to select cases from 29 provinces, cities, and autonomous regions in China. This study adopts an institutional approach to explore the influences of SES and institutional power on the state of being overweight or severely overweight (obese) among Chinese adults. It is shown that SES has a non-linear influence on being overweight or obese, higher education has a negative effect on being overweight or obese, income has an inverted U-shaped effect on being overweight or obese, and having a managerial or administrative job has a positive effect on being overweight but less so on obesity. These findings reveal that disparities in health outcome and risks are due to inequality in SES. The work unit is a stronger predictor of adults being overweight or obese than occupation. Working in the public sector has a positive effect on being overweight relative to working in the private sector, and only state institutions and government departments have a positive association with obesity. Our results indicate that institutional structure still has effects on individuals’ life chances in the era of China’s market transition.

scholarly journals Evidence for continent-wide convergent evolution and stasis throughout 150 years of a biological invasion

2021 ◽  
Author(s):  
Yihan Wu ◽  
Robert I Colautti
Keyword(s):  
Adaptive Evolution ◽  
Fossil Record ◽  
Field Experiments ◽  
Common Garden ◽  
Lythrum Salicaria ◽  
Natural Systems ◽  
Continental Scale ◽  
Evolutionary Response ◽  
Temperature Records ◽  
Growing Conditions

The extent to which evolution can rescue a species from extinction, or facilitate range expansion, depends critically on the rate, duration, and geographical extent of the evolutionary response to natural selection. While field experiments have demonstrated that adaptive evolution can occur quickly, our understanding of the duration and geographical extent of contemporary evolution in natural systems remains limited. This is particularly true for species with large geographical ranges and for timescales that lie between 'long-term' field experiments and the fossil record. Here, we introduce the Virtual Common Garden (VCG) to estimate genetic differences among phenotypes observed in natural history collections. Reconstructing 150 years of evolution in Lythrum salicaria (purple loosestrife) as it invaded across North America, we analyze phenology measurements of 3,429 herbarium records, reconstruct growing conditions from more than 12 million local temperature records, and validate predictions across three common gardens spanning 10 degrees of latitude. We find that phenology evolves rapidly and repeatedly along parallel climatic gradients during the first century of evolution. However, the rate of microevolution stalls thereafter, recapitulating macroevolutionary stasis observed in the fossil record. Our study demonstrates why preserved specimens are a critical resource for understanding limits to evolution in natural. Our results show predictability of evolution emerging at a continental scale across 15 decades of rapid, adaptive evolution.

Positive Association Between Body Mass Index and Hematologic Parameters, Including RBC, WBC and Platelet Count, in Korean Children and Adolescent

2021 ◽  
Author(s):  
Hwal Rim Jeong ◽  
Young Seok Shim
Keyword(s):  
Body Mass Index ◽  
Children And Adolescents ◽  
Body Mass ◽  
Linear Regression Analysis ◽  
Positive Association ◽  
Multiple Linear Regression Analysis ◽  
Normal Weight ◽  
Overweight And Obesity ◽  
Korean Children ◽  
Children And Adolescent

Abstract Objective: To investigate the associations between hematologic parameters and obesity in children and adolescents.Methods: A total of 7,997 subjects (4,259 boys, 3,738 girls) aged 10–18 years was enrolled and hematologic parameters, including WBC, RBC, Hb, Hct, and platelet levels, were recorded and compared against body mass index (BMI) classified into normal-weight, overweight, and obesity groups.Results : The obesity group had significantly higher mean levels of WBC (7.16 vs. 6.16 (x103/mm3), p<0.001), RBC (4.90 vs. 4.82 (x106/mm3), p<0.001), Hb (14.07 vs. 13.99 (g/dL), p<0.05), Hct (42.31 vs. 41.91 (%), p<0.001) and platelets (311.87 vs. 282.66 (x103/mm3), p<0.001) than the normal-weight group after adjusting for obesity and sex. BMI SDS was significantly positively associated with WBC (β=0.275, p<0.001), RBC (β=0.028, p<0.001), Hb (β=0.034, p<0.001), Hct (β=0.152, p<0.001), and platelets (β=8.372, p<0.001) after adjusting for age, sex, and possible socioeconomic confounders in a multiple linear regression analysis.Conclusion: Higher BMI is associated with elevated WBC, RBC, Hb, Hct and platelet counts in children and adolescents. Because higher hematologic parameters are potential risk factors for obesity-related morbidity, more attention should be paid to evaluating and interpreting hematologic parameters in children and adolescents with obesity

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