Comments to paper by S. Rattan: applying hormesis in aging research and therapy — a perspective from evolutionary biology

2001 ◽  
Vol 20 (6) ◽  
pp. 305-308 ◽  
Author(s):  
M Hercus ◽  
V Loeschcke'

The phenomenon of hormesis is discussed from an evolutionary biology perspective, i.e. in a context of fitness. Some of the evolutionary theories of aging are outlined. The influence of associations between traits and their environmental specificity is highlighted. Questions about consistency of the impact of hormetic agents across life stages are raised and finally the uniformity of definitions across disciplines is shortly discussed.

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Elizabeth R. Tuminello ◽  
S. Duke Han

Research on apolipoprotein E (APOE) has consistently revealed a relationship between the gene'sε4 allele and risk for development of Alzheimer's disease (AD). However, research with younger populations ofε4 carriers has suggested that the APOEε4 allele may in fact be beneficial in earlier ages and may only confer risk of cognitive decline later in life. Accordingly, we and others have proposed that APOE may represent an example of antagonistic pleiotropy. Antagonistic pleiotropy is an evolutionary biology concept that proposes certain genes or alleles that may differentially impact fitness during different life stages. We critically review this hypothesis in light of new research of the impact of APOE on cognition and neural integrity across the lifespan. We provide recommendations for the revision of the antagonistic pleiotropy hypothesis of APOE and suggest important avenues for future research in this area.


2020 ◽  
Vol 117 (9) ◽  
pp. 4850-4857 ◽  
Author(s):  
Mathieu Douhard ◽  
Marco Festa-Bianchet ◽  
Fanie Pelletier

Aging, or senescence, is a progressive deterioration of physiological function with age. It leads to age-related declines in reproduction (reproductive senescence) and survival (actuarial senescence) in most organisms. However, senescence patterns can be highly variable across species, populations, and individuals, and the reasons for such variations remain poorly understood. Evolutionary theories predict that increases in reproductive effort in early life should be associated with accelerated senescence, but empirical tests have yielded mixed results. Although in sexually size-dimorphic species offspring of the larger sex (typically males) commonly require more parental resources, these sex differences are not currently incorporated into evolutionary theories of aging. Here, we show that female reproductive senescence varies with both the number and sex ratio of offspring weaned during early life, using data from a long-term study of bighorn sheep. For a given number of offspring, females that weaned more sons than daughters when aged between 2 and 7 y experienced faster senescence in offspring survival in old age. By contrast, analyses of actuarial senescence showed no cost of early-life reproduction. Our results unite two important topics in evolutionary biology: life history and sex allocation. Offspring sex ratio may help explain among-individual variation in senescence rates in other species, including humans.


2016 ◽  
Vol 5 (1) ◽  
pp. 65-74
Author(s):  
Debra J. Rose

Despite the significant increase in years that an individual can now expect to live in the 21st century, there is growing evidence that the price for greater longevity may be worsening health due to the higher prevalence of nonfatal but disabling conditions. This sobering news suggests the need for expanded scientific inquiry directed at understanding the multilevel factors that promote or prevent physical activity (PA) participation and the adoption of healthy lifestyle behaviors and the types of intervention strategies that will be most effective in positively changing behavior at different life stages. Fruitful areas of future scientific inquiry include exploring other types and intensities of PA aimed at increasing PA participation while reducing sedentary behavior, better understanding the role of the physical and social environment in promoting PA participation, and designing and evaluating multilevel PA interventions that are better tailored to the activity preferences, goals, and expectations of a diverse older adult population, and flexibly delivered in real-world settings. Finally, conducting research aimed at better differentiating normal age-associated changes from those that are disease-related will be fundamental to reversing the negative stereotypes that currently shape the public’s view of the aging process.


1989 ◽  
Vol 29 (4) ◽  
pp. 241-257 ◽  
Author(s):  
Carolyn Norris-Baker ◽  
Rick J. Scheidt

Robert Kastenbaum posits that functional aging results in the overadaptation to our own routines and expectations, producing “hyperhabituation,” mental stagnation, and novaphobic response orientations. This article examines the promise and implications of this notion for two areas of environment-aging research: psychological control and environmental comprehension. Possible causal and mediating links between control and habituation are considered, as well as the impact of habituation on environmental perception, cognition, and appraisal. Personal and situational characteristics of older people likely to be at risk for habituated responses are suggested. The article also speculates about individually- and environmentally-targeted interventions which might prevent and/or ameliorate tendencies toward hyperhabituated responses among older people who reside in highly ritualized and constant environments such as long-term care institutions. Interventions subject to future evaluations include modifications for the social, physical, and policy milieux and desensitization of novaphobic responses.


Gerontology ◽  
2009 ◽  
Vol 55 (2) ◽  
pp. 205-216 ◽  
Author(s):  
Predrag Ljubuncic ◽  
Abraham Z. Reznick

2000 ◽  
Vol 12 (3) ◽  
pp. 257-257 ◽  
Author(s):  
Andrew Clarke

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.


2020 ◽  
Vol 650 ◽  
pp. 309-326
Author(s):  
A Ospina-Alvarez ◽  
S de Juan ◽  
J Alós ◽  
G Basterretxea ◽  
A Alonso-Fernández ◽  
...  

Despite the recognised effectiveness of networks of marine protected areas (MPAs) as a biodiversity conservation instrument, MPA network design frequently disregards the importance of connectivity patterns. In the case of sedentary marine populations, connectivity stems not only from the stochastic nature of the physical environment that affects dispersal of early life stages, but also from the spawning stock attributes that affect reproductive output (e.g. passive eggs and larvae) and survivorship. Early life stages are virtually impossible to track in the ocean. Therefore, numerical ocean current simulations coupled with egg and larval Lagrangian transport models remain the most common approach for the assessment of marine larval connectivity. Inferred larval connectivity may differ depending on the type of connectivity considered; consequently, the prioritisation of sites for the conservation of marine populations might also differ. Here, we introduce a framework for evaluating and designing MPA networks based on the identification of connectivity hotspots using graph theoretic analysis. As a case study, we used a network of open-access areas and MPAs off Mallorca Island (Spain), and tested its effectiveness for the protection of the painted comber Serranus scriba. Outputs from network analysis were used to (1) identify critical areas for improving overall larval connectivity, (2) assess the impact of species’ biological parameters in network connectivity and (3) explore alternative MPA configurations to improve average network connectivity. Results demonstrate the potential of graph theory to identify non-trivial egg/larval dispersal patterns and emerging collective properties of the MPA network, which are relevant for increasing protection efficiency.


Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 131 ◽  
Author(s):  
Zhenqiang Qin ◽  
Jianhui Wu ◽  
Baoli Qiu ◽  
Shaukat Ali ◽  
Andrew G. S. Cuthbertson

Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) is an important predator of the mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae), a major pest of Agave sisalana in China. Limited reports on the efficacy of C. montrouzieri against D. neobrevipes are available. This study reports the predatory efficacy and functional response of C. montrouzieri against D. neobrevipes under laboratory conditions. The prey consumption rate per day of 4th instar larvae of C. montrouzieri feeding on 1st instar D. neobrevipes nymphs (241.3 mealybugs) was the highest among the different larval life stages of the beetle. For C. montrouzieri, the prey consumption per day of adult females (19.8 mealybugs) was significantly higher compared to males (15.2 mealybugs) when feeding on 3rd instar D. neobrevipes nymphs. The functional responses of C. montrouzieri on 1st and 2nd instar D. neobrevipes nymphs were determined as Holling type II. The search rates of C. montrouzieri 4th instar larvae towards the 1st and 2nd instar nymphs of D. neobrevipes were higher than those of the other beetle life stages. In addition, the handling times of 4th instar larvae were shorter than those of the other beetle life stages. The results from this study indicate that C. montrouzieri can be used as a predator of D. neobrevipes and, therefore, it should be evaluated further for use as a biocontrol agent in D. neobrevipes management programs.


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