scholarly journals Increasing growth rate slows adaptation when genotypes compete for diffusing resources

2019 ◽  
Author(s):  
Jeremy M. Chacón ◽  
William R. Harcombe
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Spatial Scales ◽  
Reaction Diffusion ◽  
Solid Substrate ◽  
Relative Growth Rates ◽  
Reaction Diffusion Model ◽  
Evolutionary Trajectories ◽  
Actual Growth ◽  
Localized Competition

AbstractThe rate at which a species responds to natural selection is a central predictor of the species’ ability to adapt to environmental change. It is well-known that spatially-structured environments slow the rate of adaptation due to increased intra-genotype competition. Here, we show that this effect magnifies over time as a species becomes better adapted and grows faster. Using a reaction-diffusion model, we demonstrate that growth rates are inextricably coupled with effective spatial scales, such that higher growth rates cause more localized competition. This has two effects: selection requires more generations for beneficial mutations to fix, and spatially-caused genetic drift increases. Together, these effects diminish the value of additional growth rate mutations in structured environments.Author SummaryWhat determines how quickly a beneficial mutation will spread through a population? The intuitive answer is that mutations that confer faster growth rates will spread at a rate that is relative to the size of the growth-rate benefit. Indeed, this is true in a well-mixed environment where all genotypes compete globally. But most organisms don’t live in a simple well-mixed environment. Many organisms, like bacteria, live in a structured environment, such as on the surface of a solid substrate. Does life on a surface change the expectation about the spread of faster-growing mutants? We developed a mathematical model to answer this question, and found that on a surface, the actual growth rates—not just the relative growth rates—were critical to determining how fast a faster-growing mutant spread through a population. When the simulated organisms grew slowly, competition was basically global and a faster-growing mutant could pre-empt resources from far-away competitors. In contrast, when organisms grew more quickly, competition became much more localized, and the faster-growing mutant could only steal resources from neighboring competitors. This result means that there are diminishing returns to series of mutations which confer growth-rate benefits. This idea will help us predict and understand future and past evolutionary trajectories.

The Relative Growth of Parts in Palaemon Carcinus

1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Measurements ◽  
Relative Growth ◽  
Male And Female ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
The Difference ◽  
Rates Of Growth

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.

Kinetics And Morphology Of Homoepitaxial Cvd Growth On Diamond (100) And (111)

1995 ◽  
Vol 416 ◽  
Author(s):  
R. E. Rawles ◽  
W. G. Morris ◽  
M. P. D’Evelyn
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Chemical Vapor ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Arrhenius Behavior ◽  
Oriented Growth ◽  
Relative Growth Rates ◽  
Cvd Growth ◽  
Hot Filament

ABSTRACTGrowth rates for homoepitaxy of diamond (100) and (111) by hot-filament chemical vapor deposition were measured via in situ Fizeau interferometry and the surface morphologies were subsequently characterized by atomic force microscopy (AFM). (100)-oriented growth from 0.5% CH4 in H2 exhibited pure Arrhenius behavior, with an activation energy of 17±1 kcal/mol, up to a substrate temperature of 1100°C. Addition of oxygen to the feed gas resulted in an increased growth rate below 900°C, a maximum growth rate between 900 and 1000°C, and etching (of diamond) above 1050 - 1100°C. However, the presence of oxygen apparently had less effect on the surface morphology than did the (100)-to-(111) growth rate parameter α, determined directly from the relative growth rates of (100) and (111) substrates mounted side by side. During homoepitaxial growth from 0.5% CH4 in H2 at 875°C of ca. 1-micron-thick films,α = was 2.2 without oxygen and 1.3 for growth with 0.14% O2. The (100) film grown with α = 2.2 was quite smooth, while that with α = 1.3 was covered by numerous hillocks and penetration twins. AFM analysis revealed surprisingly little difference between the (111) films despite the considerable difference in α. Implications of these results for the growth mechanism are discussed.

Analyzing growth in cell cultures. I. Calculating growth rates

1986 ◽  
Vol 64 (1) ◽  
pp. 233-237 ◽  
Author(s):  
Susan R. Singer
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Rate Equations ◽  
Constant Growth Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Cell ◽  
Absolute Growth ◽  
Plant Tissue Cultures

Growth is the major parameter used to assess novel phenotypes derived from plant tissue cultures. Any quantitative analysis of growth must have an explicit rational basis. Frequently this criterion is not met. For example, the calculation (W2 − W1)/W1(W1 = initial weight; W2 = final weight) approximates neither linear nor exponential growth. Yet, it is a common method of analysis, as is the related calculation W2/W1. When absolute growth values provide insufficient information, meaningful relative growth rate equations can be utilized. Relative growth rates should be evaluated as ln (W2/W1)/(t2 − t1) for t = time, thereby yielding a constant growth rate for exponentially growing cell lines. Linear growth (root growth, for example) can be approximated by 2(W2 − W1)/((W1 + W2)(t2 − t1)). All methods of analysis we have encountered assume that relative growth at a given instant depends on total mass. The possibility exists that growth may actually be proportional to mass raised to some power less than one. For example, growth could be limited to a thin outer shell of a spherical callus. Then the relative growth rate would equal 3(W21/3 − W11/3)/(t2 − t1). Data can be seriously distorted when inappropriate calculations are used. Such distortions are exacerbated when comparisons are made. In all cases an adequate assessment of growth kinetics for each cell line and each treatment is essential.

Growth responses of six bryophyte species to different light intensities

1993 ◽  
Vol 71 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Emmanuel Rincón
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Growth Rates ◽  
Growth Analysis ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plastic Responses

The growth responses of Brachythecium rutabulum, Eurhynchium praelongum, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium purum, and Thuidiurn tamariscinum, growing under seven different light conditions, were determined in a 36-day laboratory experiment. Biomass production, relative growth rate, chlorophyll content, and morphological plastic responses (bending of the shoots) were determined following initial and final harvests. All species achieved greater biomass as irradiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophytes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear differences were observed in the ratios of chlorophyll a to b for all the species. Key words: grassland bryophytes, light intensity, growth analysis, plasticity.

On the prediction of crystal morphology. III. Equilibrium and growth behaviour of crystal faces containing multiple connected nets

1999 ◽  
Vol 55 (1) ◽  
pp. 84-94 ◽  
Author(s):  
R. F. P. Grimbergen ◽  
P. Bennema ◽  
H. Meekes
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Growth Rates ◽  
Crystal Morphology ◽  
Crystal Habit ◽  
Growth Behaviour ◽  
Equilibrium Conditions ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Surface Phases

In this paper, the equilibrium and growth behaviour of faces (hkl) with more than one connected net is studied. It is shown that for these types of orientation different surface phases exist under equilibrium conditions as a function of temperature. Depending on the exact bonding topology at the surface, flat, rough or disordered flat phases are found. Moreover, the growth rate R_{hkl} of such faces can differ significantly from the usually calculated relative growth rates based on the attachment energy. Monte Carlo simulations confirm the results from the Hartman–Perdok analyses and offer a tool for the prediction of the crystal habit as a function of supersaturation.

Stage-dependent sensitivity to ultraviolet radiation in zygotes of the brown alga Fucus serratus

Zygote ◽  
2003 ◽  
Vol 11 (2) ◽  
pp. 101-106 ◽  
Author(s):  
María Altamirano ◽  
Antonio Flores-Moya ◽  
Ralph Kuhlenkamp ◽  
Félix L. Figueroa
Keyword(s):  
Growth Rate ◽  
Uv Radiation ◽  
Growth Rates ◽  
Brown Alga ◽  
Radiation Condition ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Inhibition Of Growth ◽  
Fucus Serratus

Sensitivity to ultraviolet (UV) radiation (UV-A, λ = 315-400 nm; plus UV-B, λ = 280-315 nm) of zygotes of the brown alga Fucus serratus L. (Phaeophyta) has been assessed through effects on growth of developing germlings. Different stages of development were distinguished by considering 5 h periods of time after fertilisation. Both the stage of the zygote and the UV radiation condition significantly affected growth of developing germlings. The negative response of growth rate of early stages of the zygotes to UV radiation seemed to be caused by UV-B rather than UV-A radiation, as the lowest relative growth rates were always estimated for germlings developed from zygotes irradiated with UV-B radiation. As regards the stage of the zygote, those germlings that developed from zygotes irradiated at 5-10 h after fertilisation showed the strongest inhibition of growth compared with the other stages. These results point to polarisation as the most UV-sensitive process during the first 24 h of the development of the zygote. A non-linear relationship between the developmental stage of the zygote and the sensitivity to UV radiation is suggested.

scholarly journals GROWTH OF MANGROVE COCKLE (Anandara antiquata) CULTURED IN CAGES

2009 ◽  
Vol 34 (2) ◽  
pp. 91-96
Author(s):  
Jesaja A. Pattikawa ◽  
Elizabeth Ferdinandus
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Condition Factor ◽  
Intertidal Area ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Weight Relationship ◽  
Large Size ◽  
Length Increment

Study on growth of mangrove cockle (Anadara antiquata) was conducted in the intertidal area of Passo, Inner Ambon Bay. Three size-classes of 25 individual cockles were cultured in 1 m3 cage. Length increment data was collected every two weeks for seven periods of observation. Relative growth rate, length-weight relationship and condition factor were estimated using formula proposed by Effendie, Pauly and King, respectively. The results showed that the small size had the highest length increment and relative growth rates while the large size had the best condition factor. Length-weight relationship showed isometric growth for all categories.

Growth and development of the Murid Pseudomys novaehollandiae

1976 ◽  
Vol 24 (1) ◽  
pp. 27 ◽  
Author(s):  
CM Kemper
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth And Development ◽  
Adult Size ◽  
Body Measurements ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Straight Line ◽  
Length Measurements ◽  
Hind Foot

Growth of the hind foot, head and weight were studied from birth to 150 days of age in a captive colony of P. novaaehollandiae, and development of external body features was recorded from birth to weaning. The altricial young were sparsely haired and blind at birth and a juvenile pelage was present by about 10 days. The eyes opened at 15 (13-19) days and the young were weaned during the fourth week. Instantaneous relative growth rates showed that growth (weight) during the first 40 days was multiphasic and that the growth rate changed considerably at both the opening of the eyes and weaning. The relationships of seven body measurements (head and body, head, ear, foreleg, hind leg, hind foot and tail) were compared to a linear equivalence of weight; all showed a sigmoidal relationship except that of head and body, which was a straight line. Hind foot and head length measurements of growing animals reached 90% of adult size at about 26 days, and weight at about 85 days. In Australian murids, one group grows relatively quickly and another grows slowly.

scholarly journals Soil flood tolerance of seven genotypes of Panicum maximum Jacq.

2009 ◽  
Vol 52 (6) ◽  
pp. 1341-1348 ◽  
Author(s):  
Adriane Schio Silva ◽  
Valdemir Antônio Laura ◽  
Liana Jank
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Root Biomass ◽  
Flood Tolerance ◽  
Panicum Maximum ◽  
Above Ground Biomass ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Commercial Cultivars

The soil flood tolerance of seven genotypes of Panicum maximum Jacq. (PM11, PM34, PM40 and PM45, and the commercial cultivars Massai, Mombaça and Tanzânia) was evaluated in plants subjected to two conditions: flooded and not flooded, during a period of 14 days. Flooding significantly decreased the total and above ground biomass of PM40 and PM45. For cultivar Tanzânia, flooding decreased these two variables and also root biomass. The root, total and above ground relative growth rates were significantly reduced by flooding in cultivar Tanzânia, while in PM45 only the above ground relative growth rate was reduced. Cultivar Tanzânia showed significant differences for all variables analyzed, thus was not flood tolerant, as well as PM40 and PM45. It could be concluded that Massai, PM34, Mombaça and PM11 were the most flood tolerant genotypes.

Use of spectral analysis to estimate short-term periodicities in growth rates of brook trout Salvelinus frontinalis

1997 ◽  
Vol 54 (7) ◽  
pp. 1532-1541 ◽  
Author(s):  
W Aboul Hosn ◽  
P Dutilleul ◽  
D Boisclair
Keyword(s):  
Growth Rate ◽  
Spectral Analysis ◽  
Growth Rates ◽  
Repeated Measures ◽  
Brook Trout ◽  
Short Term ◽  
Experimental Conditions ◽  
Relative Growth Rates ◽  
Repeated Measures Design ◽  
Periodic Components

We used spectral analysis to investigate the periodic components of relative growth rates (on a mass and length basis) in two groups of six\b young-of-the-year brook trout (Salvelinus fontinalis). Fish were measured every 2 days for 25 days according to a repeated measures design in time. The predominant frequency components were estimated at the end of a stepwise procedure involving the analysis of the multifrequential periodogram. We found mainly two superimposed periodic components that resulted in short rhythms; these had a period of about 5 and 10 days for the growth rate in mass and of about 4 and 6 days for the growth rate in length (R2 = 91% for mass and 90% for length, both including an autocorrelation term). Repeatability of rhythms was assessed by ANOVA of the finite Fourier transform, which showed that the two groups of fish reared under the same experimental conditions exhibited growth rhythms that were not significantly different from each other. On that basis, we present a harmonic model which predicts short-term variation in growth rate of brook trout in mass (R2pred = 0.73, with an autocorrelation term) and in length (R2pred = 0.72).

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