scholarly journals Low concordance of short‐term and long‐term selection responses in experimental Drosophila populations

2020 ◽  
Vol 29 (18) ◽  
pp. 3466-3475 ◽  
Author(s):  
Anna Maria Langmüller ◽  
Christian Schlötterer
Keyword(s):  
Short Term ◽  
Term Selection ◽  
Selection Responses

scholarly journals Long-term evolution is surprisingly predictable in lattice proteins

2013 ◽  
Vol 10 (82) ◽  
pp. 20130026 ◽  
Author(s):  
Michael E. Palmer ◽  
Arnav Moudgil ◽  
Marcus W. Feldman
Keyword(s):  
Natural Selection ◽  
Basins Of Attraction ◽  
Long Term Outcomes ◽  
Short Term ◽  
Term Selection ◽  
Term Evolution ◽  
Evolutionary Success ◽  
Lattice Proteins

It has long been debated whether natural selection acts primarily upon individual organisms, or whether it also commonly acts upon higher-level entities such as lineages. Two arguments against the effectiveness of long-term selection on lineages have been (i) that long-term evolutionary outcomes will not be sufficiently predictable to support a meaningful long-term fitness and (ii) that short-term selection on organisms will almost always overpower long-term selection. Here, we use a computational model of protein folding and binding called ‘lattice proteins’. We quantify the long-term evolutionary success of lineages with two metrics called the k -fitness and k -survivability. We show that long-term outcomes are surprisingly predictable in this model: only a small fraction of the possible outcomes are ever realized in multiple replicates. Furthermore, the long-term fitness of a lineage depends only partly on its short-term fitness; other factors are also important, including the ‘evolvability’ of a lineage—its capacity to produce adaptive variation. In a system with a distinct short-term and long-term fitness, evolution need not be ‘short-sighted’: lineages may be selected for their long-term properties, sometimes in opposition to short-term selection. Similar evolutionary basins of attraction have been observed in vivo , suggesting that natural biological lineages will also have a predictive long-term fitness.

Primordialism, Evolutionary Theory and Ethnic Violence in the Balkans: Opportunities and Constraints for Theory and Policy

2000 ◽  
Vol 33 (1) ◽  
pp. 37-65 ◽  
Author(s):  
Frank P. Harvey
Keyword(s):  
Evolutionary Theory ◽  
Belief Systems ◽  
Ethnic Violence ◽  
Short Term ◽  
Term Selection ◽  
The Balkans ◽  
Selection Processes ◽  
Group Survival ◽  
Selection Mechanisms

The literature on evolutionary theory tends to address questions of ethnicity from two perspectives: (1) macro, or long–term selection processes associated with basic human preferences for individual or group survival, ethnic identity or kinship affiliations; and (2) intermediate selection mechanisms associated with the fitness and adaptability of specific cultures, religions or belief systems in different regions of the world. Comparatively less time has been spent addressing micro–evolutionary questions about the timing, escalation and duration of ethnic violence — that is, micro or short–term selection processes and fitness mechanisms that account for the escalation and/or duration of ethnic hatreds, violence or war at a particular time.

scholarly journals A complex multi-locus, multi-allelic genetic architecture underlying the long-term selection-response in the Virginia body weight line of chickens

2017 ◽  
Author(s):  
Yanjun Zan ◽  
Zheya Sheng ◽  
Lars Rönnegård ◽  
Christa F. Honaker ◽  
Paul B. Siegel ◽  
...  
Keyword(s):  
Body Weight ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Selection Response ◽  
Multiple Alleles ◽  
Term Selection ◽  
Selection Responses ◽  
Genome Wide ◽  
Genetic Mechanisms

AbstractThe ability of a population to adapt to changes in their living conditions, whether in nature or captivity, often depends on polymorphisms in multiple genes across the genome. In-depth studies of such polygenic adaptations are difficult in natural populations, but can be approached using the resources provided by artificial selection experiments. Here, we dissect the genetic mechanisms involved in long-term selection responses of the Virginia chicken lines, populations that after 40 generations of divergent selection for 56-day body weight display a nine-fold difference in the selected trait. In the F15 generation of an intercross between the divergent lines, 20 loci explained more than 60% of the additive genetic variance for the selected trait. We focused particularly on seven major QTL and found that only two fine-mapped to single, bi-allelic loci; the other five contained linked loci, multiple alleles or were epistatic. This detailed dissection of the polygenic adaptations in the Virginia lines provides a deeper understanding of genome-wide mechanisms involved in the long-term selection responses. The results illustrate that long-term selection responses, even from populations with a limited genetic diversity, can be polygenic and influenced by a range of genetic mechanisms.

scholarly journals How adaptive plasticity evolves when selected against

2018 ◽  
Author(s):  
Alfredo Rago ◽  
Kostas Kouvaris ◽  
Tobias Uller ◽  
Richard Watson
Keyword(s):  
Natural Selection ◽  
Environmental Change ◽  
Coarse Grained ◽  
Adaptive Plasticity ◽  
Short Term ◽  
Local Optima ◽  
Term Selection ◽  
Selection For ◽  
The Individual

AbstractAdaptive plasticity allows organisms to cope with environmental change, thereby increasing the population’s long-term fitness. However, individual selection can only compare the fitness of individuals within each generation: if the environment changes more slowly than the generation time (i.e., a coarse-grained environment) a population will not experience selection for plasticity even if it is adaptive in the long-term. How does adaptive plasticity then evolve? One explanation is that, if competing alleles conferring different degrees of plasticity persist across multiple environments, natural selection between lineages carrying those alleles could select for adaptive plasticity (lineage selection).We show that adaptive plasticity can evolve even in the absence of such lineage selection. Instead, we propose that adaptive plasticity in coarse-grained environments evolves as a by-product of inefficient short-term natural selection. In our simulations, populations that can efficiently respond to selective pressures follow short-term, local, optima and have lower long-term fitness. Conversely, populations that accumulate limited genetic change within each environment evolve long-term adaptive plasticity even when plasticity incurs short-term costs. These results remain qualitatively similar regardless of whether we decrease the efficiency of natural selection by increasing the rate of environmental change or decreasing mutation rate, demonstrating that both factors act via the same mechanism. We demonstrate how this mechanism can be understood through the concept of learning rate.Our work shows how plastic responses that are costly in the short term, yet adaptive in the long term, can evolve as a by-product of inefficient short-term selection, without selection for plasticity at either the individual or lineage level.

Elite populations for conifer breeding and gene conservation

1996 ◽  
Vol 26 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Claire G. Williams ◽  
J.L. Hamrick
Keyword(s):  
Tree Breeding ◽  
Forest Tree ◽  
Selection Response ◽  
Gene Conservation ◽  
Forest Tree Breeding ◽  
Short Term ◽  
Term Selection ◽  
Loss Of Genetic Diversity ◽  
Advanced Generation

Elite populations managed for short-term gain have received increasing attention as advanced-generation breeding strategies have taken shape for forest tree species. They are prevalent for two reasons: (1) their short-term gains provide justification for the rising costs of recurrent forest tree breeding and (2) the advent of control-pollinated seed production has reduced the requirement for a large number of unrelated selections. This paper addresses the concept of an elite population, its potential for compressed generation intervals, its predicted long-term selection response, as well as the concomitant risks of severe inbreeding depression and loss of genetic diversity.

scholarly journals Genetic Resource of Muscovy Duck (Cairina moschata): Profile and Potential Production as Meat Producer

2018 ◽  
Vol 28 (3) ◽  
pp. 129 ◽  
Author(s):  
Hasil Tamsil
Keyword(s):  
Egg Production ◽  
Genetic Resource ◽  
High Growth ◽  
High Growth Rate ◽  
Muscovy Duck ◽  
Short Term ◽  
Term Selection ◽  
Cairina Moschata

Muscovy duck is a type of waterfowl that has a relatively better growth and percentage compared to ducks. Duck meat has high-quality because of its low fat and savory flavor. Muscovy duck is relatively resistant to the disease and is able to use low-quality feed, but has the disadvantage of low egg production. The development of Muscovy duck as a producer of meat can be done through two approaches, namely the long-term and short-term. The long-term approach is carried out by selecting Muscovy duck which has high growth rate and high meet quality. The selection can be done in two ways, namely directly on the nature of growth and the quality of meat, and indirectly by choosing a marker of growth (morphology, biochemistry or diversity of DNA/ RNA). Short-term selection can be done by bringing in superior Muscovy duck from the outside to be developed by farmers and crossing male Muscovy duck with the layer Indian Runner ducks to produce Serati ducks.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield
Keyword(s):  
Auditory Processing ◽  
Short Term Memory ◽  
Group Differences ◽  
Long Term Memory ◽  
Short Term ◽  
Significant Group ◽  
Term Memory ◽  
Memory And Attention ◽  
Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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