scholarly journals Drift on holey landscapes as a dominant evolutionary process

2021 ◽  
Author(s):  
Ned A Dochtermann ◽  
Brady Klock ◽  
Derek A Roff ◽  
Raphael Royaute
Keyword(s):  
Life History ◽  
Evolutionary Theory ◽  
Quantitative Traits ◽  
Life History Traits ◽  
Evolutionary Process ◽  
High Dimensional ◽  
Physiological Processes ◽  
Non Linear ◽  
Classical Models ◽  
Trait Correlations

Phenotypes typically display integration, i.e. correlations between traits. For quantitative traits--like many behaviors, physiological processes, and life-history traits--patterns of integration are often assumed to have been shaped by the combination of linear, non-linear, and correlated selection, with trait correlations representative of optimal combinations. Unfortunately, this assumption has rarely been critically tested, in part due to a lack of clear alternatives. Here we show that trait integration across 6 phyla and 60 species (including both Plantae and Animalia) is consistent with evolution across high dimensional "holey landscapes" rather than classical models of selection. This suggests that the leading conceptualizations and modeling of the evolution of trait integration fail to capture how phenotypes are shaped. Instead, traits are integrated in a manner contrary to predictions of dominant evolutionary theory.

scholarly journals Hybridization affects life-history traits and host specificity in Diorhabda spp

2017 ◽  
Author(s):  
E.V. Bitume ◽  
D. Bean ◽  
A.R. Stahlke ◽  
R.A. Hufbauer
Keyword(s):  
Biological Control ◽  
Life History ◽  
Host Specificity ◽  
Life History Traits ◽  
Evolutionary Process ◽  
Control Program ◽  
Cross Hybridization ◽  
Evolutionary Force ◽  
Two Generations ◽  
Adult Mass

AbstractHybridization is an influential evolutionary process that has been viewed alternatively as an evolutionary dead-end or as an important creative evolutionary force. In colonizing species, such as introduced biological control agents, hybridization can negate the effects of bottlenecks and genetic drift through increasing genetic variation. Such changes could be beneficial to a biological control program by increasing the chances of establishment success. However, hybridization can also lead to the emergence of transgressive phenotypes that could alter host specificity; an important consideration when assessing potential non-target impacts of planned agents. In a series of lab experiments, we investigated the effects of hybridization between three species of Diorhabda released to control invasive Tamarix (saltcedar) on life history traits through two generations, and through the third generation for one cross. Depending on the cross, hybridization had either a positive or neutral impact on development time, adult mass, and fecundity. We evaluated preference for the target (saltcedar) relative to a non-target host Tamarixaphylla (athel), and found host specificity patterns varied in two of the three hybrids, demonstrating the possibility for hybridization to alter host preference. Importantly, the overall effects of hybridization were inconsistent by cross, leading to unpredictability in the outcome of using hybrids in biological control.

scholarly journals Telomere length covaries with age across an elevational gradient in a Mediterranean lizard

2019 ◽  
Author(s):  
Pablo Burraco ◽  
Mar Comas ◽  
Senda Reguera ◽  
Francisco Javier Zamora-Camacho ◽  
Gregorio Moreno-Rueda
Keyword(s):  
Life History ◽  
Body Size ◽  
Telomere Length ◽  
Body Condition ◽  
Life History Traits ◽  
Elevational Gradient ◽  
Habitat Characteristics ◽  
Tail Autotomy ◽  
Non Linear

AbstractThe timing of organisms’ senescence is developmentally programmed but also shaped by the interaction between environmental inputs and life-history traits. In ectotherms, ageing dynamics are still poorly understood despite their particularities concerning thermoregulation, regeneration capacity, or growth trajectory. Here, we investigate the role of life-history traits such as age, sex, body size, body condition, and tail autotomy (i.e self-amputation) in shaping telomere length of six populations of the Algerian sand lizard (Psammodromus algirus) distributed across an elevational gradient from 300 to 2500 meters above the sea level. Additionally, we show in a review table the available information on reptiles’ telomere length. We found that telomeres elongated with lizards’ age. We also observed that body size and age class showed a positive relationship, suggesting that cell replication did not shorten lizards’ telomeres by itself. Elevation affected telomere length in a non-linear way, a pattern that mirrored the variation in age structure across elevation. Telomere length was unaffected by tail autotomy, and was sex-independent, but positively correlated with body condition. Our results show that telomeres elongate throughout the first four years of lizards’ lifetime, a process that stress the role of telomerase in maintaining ectothermic telomeres, and, likely, in extending lifespan in organisms with indeterminate growth. Regarding the non-linear impact that elevation had on telomere length of lizards, our results suggest that habitat (mainly temperature) and organisms’ condition might play a key role in regulation ageing rate. Our findings emphasize the relevance of understanding species’ life histories (e.g. age and body condition) and habitat characteristics for fully disentangling the causes and consequences of lifespan trajectory.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

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