Punctuation

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Large Population ◽  
Rapid Change ◽  
Biological Species ◽  
Rate Of Change ◽  
Quantum Evolution ◽  
Stabilizing Selection ◽  
Intended Meaning ◽  
Rate Of Evolution ◽  
Directional Change ◽  
Punctuated Evolution

In punctuated evolution (Eldredge and Gould, 1972) periods of relatively little change (“stasis”) are punctuated by episodes of relatively rapid change in the rate of evolution of a quantitative morphological trait, as seen in the fossil record of morphology. According to Simpson (1984), the term quantum evolution, refers to the same thing. Like Eldredge and Gould, Simpson contrasted quantum evolution with phyletic change, or sustained directional evolution without branching; considered that it could be associated with speciation (though also with phyletic evolution; p. 206); and even mentioned interrupted equilibra “In phyletic evolution equilibrium of the organism-environment system is continuous, or nearly so, although the point of equilibrium may and usually does shift. In quantum evolution equilibrium is lost, and a new equilibrium is reached”. I use the term “punctuation” rather than “quantum” because it less ambiguously describes change in rate of evolution. In its original meaning (from the Latin quantus), quantum means quantity. But quantum change, as mentioned by Simpson, is identified with the “quanta” of physics, which are discrete units of energy. This could encourage mistaken identification of punctuated change with the origin of discrete novelties, not the intended meaning of punctuated evolution, which is periodically altered rate of change in a continuously variable, quantitative trait. Mayr, Eldredge, Gould, and others (e.g., Stanley, 1979, 1981) explain stasis and punctuation in terms of speciation. Speciational punctuation hypotheses see stasis as due to the characteristics of established biological species, such as gene flow within interbreeding populations, large population size, heterogeneity of the species environment that retards directional change, developmental integration, canalization, coadapted genomes, stabilizing selection, and frequently reversing evolution over time within established species (Eldredge and Gould, 1997). These factors have been summarized by the term “gene-pool cohesiveness” (Mayr, 1989) or “developmental coherences” (Gould, 1989b), though the causes of stasis under the speciational hypothesis are admittedly vague and debatable (for reviews of other possible causes of stasis, see Williamson, 1987; Coyne and Charlesworth, 1997; Van Valen, 1982a; Spicer, 1993).

Decreasing water pressure cues ‘bailout’ in seaweed-associated crustaceans

2020 ◽  
Vol 653 ◽  
pp. 121-129
Author(s):  
RB Taylor ◽  
S Patke
Keyword(s):  
Water Pressure ◽  
Rapid Change ◽  
Brown Seaweed ◽  
Model System ◽  
Rate Of Change ◽  
Suitable Habitat ◽  
Changing Light ◽  
Surface Increase ◽  
Reduced Water ◽  
Transparent Chamber

Small mobile crustaceans are abundant on seaweeds. Many of these crustaceans rapidly abandon their host if it is detached from the seafloor and floats towards the surface, but the trigger for this ‘bailout’ behaviour is unknown. We tested 2 potential cues, i.e. rapid change in light and rapid change in water pressure, using >1 mm epifauna on the brown seaweed Carpophyllum plumosum as a model system. Bailout occurred in response to reduced water pressure, but not to changing light, as (1) bailout occurred at similar rates in light and dark, (2) bailout occurred on the seafloor when water pressure was reduced within a transparent chamber by the equivalent of ~0.5 m depth or more, and (3) little bailout occurred when water pressure was held constant within the chamber while seaweeds were raised to the surface. Increase in pressure (simulating sinking) did not induce bailout. The rate of bailout increased with increasing magnitude of pressure reduction but was not influenced greatly by the rate of change of pressure within the range tested (up to an equivalent of 0.4 m depth s-1). The use of pressure rather than light as a cue for bailout is consistent with the need for seaweed-associated crustaceans to rapidly abandon a detached host and relocate to suitable habitat during both day and night.

The varying influence of social and linguistic factors on language stability and change: The case of Eskilstuna

2009 ◽  
Vol 21 (1) ◽  
pp. 97-133 ◽  
Author(s):  
Eva Sundgren
Keyword(s):  
Large Scale ◽  
Language Change ◽  
Rapid Change ◽  
Rate Of Change ◽  
Social Forces ◽  
Trend Study ◽  
Continuity And Change ◽  
Gender And Age ◽  
Regional Dialect ◽  
Empirical Material

AbstractContinuity and Change in Present-Day Swedish: Eskilstuna Revisited is a large-scale study of language change in real time. In this article, the focus is on the results of a trend study and the analysis of how extralinguistic and linguistic factors influence how language varies and changes.The empirical material consists of informal conversationlike interviews, in which seven morphological and morphophonological variables have been analyzed in terms of the traditional extralinguistic factors of social group, gender, and age, as well as in terms of social networks. These morpho(phono)logical variables are sociolinguistically marked and have been hypothesized to show a process of more or less rapid change from regional dialect toward spoken standard. The rate of change at the level of the community has been slow, however. Comparisons between the influence of extralinguistic and linguistic factors indicate that social forces are more influential than linguistic ones.

Grazing intensity and vegetation change

1994 ◽  
Vol 18 ◽  
pp. 23-29
Author(s):  
J. A. Milne
Keyword(s):  
Vegetation Change ◽  
Management Practices ◽  
Production Systems ◽  
Rapid Change ◽  
Grazing Intensity ◽  
Abundant Species ◽  
Rate Of Change ◽  
Large Herbivores ◽  
Current State ◽  
The Uk

AbstractChange in the semi-natural vegetation of the hills and uplands of the UK is a relatively slow process. Whilst exogenous influences, such as climate and air quality, can influence the rate of change, the principal means whereby more rapid change can occur is through the actions of man in managing such resources to meet a range of objectives. Burning and grazing by large herbivores are the two most important management practices adopted and their interaction is central to the maintenance of vegetation in its current state and to its direction of change. This paper reviews how vegetation change associated with grazing occurs, how it can be measured, what the critical levels of grazing are for the most abundant species and what the implications of grazing are for nutrient supply for animal production systems.

scholarly journals Plants Are the Drivers of Geographic Variation of Floral Scents in a Highly Specialized Pollination Mutualism: a Study of Ficus Hirta in China

2021 ◽  
Author(s):  
Deng Xiaoxia ◽  
Buatois Bruno ◽  
Peng Yan-Qiong ◽  
Hui Yu ◽  
Cheng Yufen ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Large Population ◽  
Stabilizing Selection ◽  
Strict Sense ◽  
Pollinator Attraction ◽  
Neutral Drift ◽  
Pollination Mutualism ◽  
Ficus Hirta ◽  
Pattern Of Variation ◽  
Genetic Structures

Abstract BackgroundFloral volatiles play an important role in pollinator attraction. This is particularly true in obligate brood site pollination mutualisms. The plants generally produce inconspicuous flowers and depend on odours to attract to their inflorescences specialised pollinators that breed in their floral structures. Little is known about the processes shaping the micro-evolution of these floral odours. Here, we investigate geographic variation of floral odour in an obligate host-specific brood site pollination mutualism where plant and pollinator genetic structures are different, Ficus hirta and its specialised pollinators.ResultsWe evidence progressive geographic divergence of floral odours. The pattern of variation fits plant genetic structure but differs from pollinating insect structuring into species and populations. In our study system, the evolution of receptive floral odour presents a pattern that is not distinguishable from neutral drift that is not canalised by the insects.ConclusionWe propose that this pattern characterises obligate brood site pollination mutualisms in which pollinators are host specific and dispersal is limited. Insects with their short generation times and large population sizes track variation in host receptive inflorescence odours. Plants are the drivers and insects the followers. Strict sense plant-insect co-evolution is not involved. In contrast, stabilizing selection may be at work in more dispersive brood site pollination mutualisms, while pollinators may mediate local interspecific plant floral odour convergence when plant species share local pollinators.

scholarly journals Evolution of the threshold temperature definition of a heat wave vs. evolution of the minimum mortality temperature: a case study in Spain during the 1983–2018 period

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
J. A. López-Bueno ◽  
J. Díaz ◽  
F. Follos ◽  
J. M. Vellón ◽  
M. A. Navas ◽  
...  
Keyword(s):  
Temporal Evolution ◽  
Local Level ◽  
Rate Of Change ◽  
Threshold Temperature ◽  
Rate Of Evolution ◽  
Threshold Temperatures ◽  
Adaptation To Heat ◽  
Linear Fit ◽  
Minimum Mortality Temperature ◽  
Definition Of

Abstract Background An area of current study concerns analysis of the possible adaptation of the population to heat, based on the temporal evolution of the minimum mortality temperature (MMT). It is important to know how is the evolution of the threshold temperatures (Tthreshold) due to these temperatures provide the basis for the activation of public health prevention plans against high temperatures. The objective of this study was to analyze the temporal evolution of threshold temperatures (Tthreshold) produced in different Spanish regions during the 1983–2018 period and to compare this evolution with the evolution of MMT. The dependent variable used was the raw rate of daily mortality due to natural causes ICD X: (A00-R99) for the considered period. The independent variable was maximum daily temperature (Tmax) during the summer months registered in the reference observatory of each region. Threshold values were determined using dispersion diagrams (annual) of the prewhitened series of mortality temperatures and Tmax. Later, linear fit models were carried out between the different values of Tthreshold throughout the study period, which permitted detecting the annual rate of change in Tthreshold. Results The results obtained show that, on average, Tthreshold has increased at a rate of 0.57 ºC/decade in Spain, while Tmax temperatures in the summer have increased at a rate of 0.41 ºC/decade, suggesting adaptation to heat. This rate of evolution presents important geographic heterogeneity. Also, the rate of evolution of Tthreshold was similar to what was detected for MMT. Conclusions The temporal evolution of the series of both temperature measures can be used as indicators of population adaptation to heat. The temporal evolution of Tthreshold has important geographic variation, probably related to sociodemographic and economic factors, that should be studied at the local level.

scholarly journals WASTE MANAGEMENT IN THE PIMPRI CHINCHWAD, PUNE, INDIA

2017 ◽  
Vol 3 (1) ◽  
pp. 01 ◽  
Author(s):  
Harsha Chatrath
Keyword(s):  
Waste Management ◽  
19Th Century ◽  
Industrial Revolution ◽  
Large Population ◽  
Rapid Change ◽  
International Level ◽  
Waste Generation ◽  
The World ◽  
Solid Waste Generation ◽  
Academic Implications

Purpose: To create awareness about utilization of waste Methodology: Survey of utilization of garbage at international level with special reference to Pimpri Chinchwad area of PuneFindings:  Garbage can is utilized for making manure, vermin compost, generating electricity, etc.Social/ Academic Implications: Clean India Green IndiaOriginality/Novelty of article:  Recycling of all types of garbage for fruitful utilization.The beginning of civilization led to development around river banks. Things could be managed during those days as people lived in harmony with nature. The scenario changed with industrialization which started creating havoc at the end of 19th century when the industrial revolution took the world of the consumer by leaps and bounds, which led to the concentration of population packets in and around the industrial areas. This rapid change in the development brought forth many challenges before the planning authorities especially the provision of basic amenities and hygienic place of living. The biggest challenge before the administration was and is to manage the waste generated by this large population. The solid waste generation has become a continuous global problem at all levels throughout the world. [1]

Possible chemical controls of illite/smectite composition during diagenesis

1985 ◽  
Vol 49 (352) ◽  
pp. 387-391 ◽  
Author(s):  
B. Velde
Keyword(s):  
Oxidation State ◽  
Clay Mineral ◽  
Mixed Layer ◽  
Mineral Assemblage ◽  
Rapid Change ◽  
Rate Of Change ◽  
Burial Diagenesis ◽  
Clay Mineral Assemblage ◽  
Layer Mineral

AbstractRe-interpretation of the significance of phase assemblages present in two sequences of rocks having experienced similar burial diagenesis allows one to establish that the change of oxidation state of iron in sediments could have the effect of changing the smectite content of the mixed layer mineral. This is used to explain an almost isothermal change in the composition of a sequence while others do not show such a rapid change. An indicator of the reaction is seen in the composition of the chlorite present in the rocks which is iron-rich and alumina-poor compared to chlorites in rocks showing a slower rate of change in the smectite content of the mixed-layered mineral. In order to reveal such a relation, one must make an analysis of the clay mineral assemblage, especially in the number of phases present during the course of diagenesis.

Exploring linguistic malleability across the life span: Age-specific patterns in quotative use

2015 ◽  
Vol 44 (4) ◽  
pp. 457-496 ◽  
Author(s):  
Isabelle Buchstaller
Keyword(s):  
Life Span ◽  
Language Ideologies ◽  
Rapid Change ◽  
Rate Of Change ◽  
Small Scale ◽  
Low Frequencies ◽  
Trend Data ◽  
Age Grading ◽  
The Moment ◽  
The Individual

AbstractThis article explores the degree and kind of lability that occurs throughout the life span of the individual during ongoing rapid change in the quotative system. Two comparative analyses trace speakers' use ofbe likeacross a shorter and a longer time span. Trend data reveal that the robust change is arrested in the middle age brackets; speakers in their thirties seem to display ‘retrograde movement’ (Sankoff & Wagner 2006) away from the community-wide change. This finding could be interpreted as incipient age-grading. A small-scale panel sample collected forty-two years after the initial interview suggests that some older speakers participate in the trend, albeit at very low frequencies. This finding, while exploratory at the moment, might be interpreted as indicative of ‘life-span change’ (Sankoff 2005). A conception of the change in progress in the quotative system as monotonous would thus both under and overestimate the rate of change. (Change across the life span, age-grading, retrograde change, life-span change, quotation, style, language ideologies)*

scholarly journals Selection of new inversions in multi-locus genetic systems

1973 ◽  
Vol 21 (2) ◽  
pp. 167-183 ◽  
Author(s):  
Brian Charlesworth ◽  
Deborah Charlesworth
Keyword(s):  
Sex Differences ◽  
Selection Pressure ◽  
Stable Equilibrium ◽  
Large Population ◽  
Approximate Expression ◽  
Rate Of Change ◽  
Initial Population ◽  
Square Root ◽  
Locus System ◽  
Selection Of

SUMMARYAn approximate expression, is derived for the rate of change in frequency of an inversion introduced at a low initial frequency into a multi-locus system at equilibrium under recombination and selection. It is shown that this expression gives accurate predictions of the rate of progress of the inversion, even if the initial population is perturbed somewhat from equilibrium. Extensions to the cases where there are sex differences in recombination and selection are considered. An implication of the results is that selection pressure for newly arisen inversions depends on the existence of a stable equilibrium with linkage disequilibrium. The expected chance of survival of a new inversion in a large population is shown to be approximately one half the square root of the loss in fitness due to recombination.

Modeling rate sensitivity of exercise transient responses to limb motion

2014 ◽  
Vol 117 (7) ◽  
pp. 699-705 ◽  
Author(s):  
Stanley M. Yamashiro ◽  
Takahide Kato
Keyword(s):  
Rapid Change ◽  
Rate Sensitivity ◽  
Rate Of Change ◽  
Fast Component ◽  
Transient Responses ◽  
Feed Forward ◽  
Exercise Load ◽  
Proposed Model ◽  
Sensitivity Rate ◽  
Response To Exercise

Transient responses of ventilation (V̇e) to limb motion can exhibit predictive characteristics. In response to a change in limb motion, a rapid change in V̇e is commonly observed with characteristics different than during a change in workload. This rapid change has been attributed to a feed-forward or adaptive response. Rate sensitivity was explored as a specific hypothesis to explain predictive V̇e responses to limb motion. A simple model assuming an additive feed-forward summation of V̇e proportional to the rate of change of limb motion was studied. This model was able to successfully account for the adaptive phase correction observed during human sinusoidal changes in limb motion. Adaptation of rate sensitivity might also explain the reduction of the fast component of V̇e responses previously reported following sudden exercise termination. Adaptation of the fast component of V̇e response could occur by reduction of rate sensitivity. Rate sensitivity of limb motion was predicted by the model to reduce the phase delay between limb motion and V̇e response without changing the steady-state response to exercise load. In this way, V̇e can respond more quickly to an exercise change without interfering with overall feedback control. The asymmetry between responses to an incremental and decremental ramp change in exercise can also be accounted for by the proposed model. Rate sensitivity leads to predicted behavior, which resembles responses observed in exercise tied to expiratory reserve volume.

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