scholarly journals The Time Scale of Evolution

2018 ◽  
Author(s):  
Diogo Passagem-Santos ◽  
Lilia Perfeito
Keyword(s):  
Growth Rate ◽  
Experimental Evolution ◽  
Relative Fitness ◽  
Selective Sweeps ◽  
Evolutionary Time ◽  
Common Reference ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Different Populations ◽  
Probability Of Fixation

AbstractFitness is a measure of how quickly alleles change in frequency under natural selection. Time is always implicit in evolutionary models but its units are rarely made explicit. When measuring phenotypes such as absolute growth rate, the units of measurement need to be made explicit. By contrasting measures of fitness and growth rate, we uncovered a curious effect, by which evolutionary time runs at different speeds depending on how restricted population growth is. In other words, when the generation time of a population is externally imposed, relative fitness per generation is no longer an accurate measure of differences between genotypes. We explore this effect and describe how it affects selective sweeps, probability of fixation of beneficial mutations and adaptation dynamics. Moreover, we show that different populations cannot be compared unless they share a common reference and that our inference of epistasis can be biased by this temporal effect. Finally, we suggest less biased ways to measure selection in experimental evolution.

A comparative study on the nursery culture of hatchery-reared sub-adult cupped oyster, Crassostrea iredalei (Faustino, 1932), in an earthen pond and a mangrove canal

2018 ◽  
Vol 26 (4) ◽  
pp. 217-222
Author(s):  
Premwadee Chueachat ◽  
Woraporn Tarangkoon ◽  
Suwat Tanyaros
Keyword(s):  
Growth Rate ◽  
Comparative Study ◽  
Condition Index ◽  
Daily Growth ◽  
Nursery Culture ◽  
Absolute Growth Rate ◽  
Significant Difference ◽  
Adult Oyster ◽  
Absolute Growth ◽  
The Mean

Abstract A comparative study on the nursery culture of the spat of the tropical oyster, Crassostrea iredalei, in an earthen pond and a mangrove canal was conducted over two months. The results revealed no differences in the absolute growth rate determined by shell width between the two culture sites (P < 0.05). Sub-adult oysters cultured in the mangrove canal showed a higher absolute growth rate in shell length and a higher daily growth rate than the oysters cultured in the earthen pond (P < 0.05). The mean survival rate of sub-adult oysters cultured in the earthen pond (99.8 ± 0.2%) was significantly higher than for those cultured in the mangrove canal (66.7 ± 31.4%). Decreased density from the loss of sub-adult oyster nursery culture in the mangrove canal led to higher growth performance than in the earthen pond. However, no difference was found for the fraction of oysters larger or smaller than 5 cm for the two culture sites (P < 0.05). A significant difference was noted in the Condition Index (CI) between the two culture sites (P < 0.05). The high primary productivity in mangroves is a major supporter of higher CI in sub-adult oysters cultured in mangrove canals versus in earthen ponds. Water exchange in the earthen pond to maintain calcium and magnesium concentrations resulted in no differences in the shell compressibility of sub-adult oysters compared with those cultured in the mangrove canal.

scholarly journals Soil preparation and NPK fertilization in the planting of five Atlantic Rainforest species in a clay extraction area

2020 ◽  
Vol 42 ◽  
pp. e36
Author(s):  
Ana Paula Braido Pinheiro ◽  
Adriele Dos Santos Jardim ◽  
João Vitor Garcia Silva ◽  
Adriano Alves Fernandes ◽  
Fábio Ribeiro Pires ◽  
...  
Keyword(s):  
Growth Rate ◽  
Experimental Design ◽  
Native Species ◽  
Atlantic Rainforest ◽  
Extraction Area ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Soil Preparation ◽  
Number Of Leaves ◽  
Npk Fertilization

The occurrence of degraded areas worldwide grows each year and measures must be taken to mitigate degradation and to recover these areas. The aim of this study was to assess the effect of soil preparation and NPK levels on the growth of five native species of the Atlantic Rainforest in clay extraction area. The experimental design was randomized block in a split-split plot arrangement with four replications. Subsoiling and scarification soil preparation represented main plots.  Doses of NPK 04-14-08: 0; 40; 80;160; and 320 g pit-1 represented subplots and Atlantic Rainforest native species represented sub-subplots. Absolute growth rate, stem diameter and number of leaves were evaluated, 210 days after planting. The type of soil preparation did not influence the development of the species. The best dose for Dalbergia ecastaphyllum, Inga laurina, Protium heptaphyllum and Psidium cattleyanum were 176.49, 150.18, 199.25 and 166.48 g pit-1 of NPK, respectively. Schinus terebinthifolius was highly responsive to planting fertilization, being recommended 320 g pit-1 of NPK. All species are indicated for area recovery.

Latitude and Relative Growth in the Razor Clam, Siliqua Patula

1931 ◽  
Vol 8 (3) ◽  
pp. 228-249
Author(s):  
F. W. WEYMOUTH ◽  
H. C. McMILLIN ◽  
WILLIS H. RICH
Keyword(s):  
Growth Rate ◽  
Life Span ◽  
Relative Growth Rate ◽  
Growth Data ◽  
Natural Conditions ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Mathematical Expressions ◽  
Wide Range ◽  
Absolute Growth

1. The present paper is a study of the growth of a clam (Siliqua patula) under natural conditions and over a wide range of latitude. 2. Various constants derived from the growth data are compared for the different localities. For this species, over the range considered, growth in the southern localities as compared with the northern is initially more rapid but less sustained, leads to a smaller total length and is associated with a shorter life span. 3. Reasons are presented for considering the relative growth-rate as a particularly significant constant leading to more sound biological conclusions than the use of the absolute growth-rate. 4. On the basis of the relative growth-rate, current mathematical expressions for the course of growth are discussed and a formula used which emphasises Minot's conception of a growth-rate constantly declining with age. This expression L = Be-ce-ce-kt, in which L = length at time t, e = base of natural logarithms, and B, c and k are constants, is found to graduate the extensive data in clam growth with significant accuracy.

Growth and Development of Bulbous Oatgrass (Arrhenatherum elatiusvar.bulbosum)

1990 ◽  
Vol 4 (4) ◽  
pp. 843-848 ◽  
Author(s):  
Karin Tanphiphat ◽  
Arnold P. Appleby
Keyword(s):  
United States ◽  
Growth Rate ◽  
Growth And Development ◽  
Perennial Grass ◽  
The United States ◽  
Willamette Valley ◽  
Stem Base ◽  
Absolute Growth Rate ◽  
Early Autumn ◽  
Absolute Growth

Bulbous oatgrass, a weed in parts of the United States and Europe, is an unusual grass, which forms corms at the stem base. Growth and development of this creeping perennial grass was investigated in the field and in pots outdoors. Under the mild climate of the Willamette Valley, Oregon, shoots emerged in early autumn. Plants grew vegetatively and formed corms during the winter and spring. Aboveground portions of the plant stopped growing and senesced in the summer. The absolute growth rate of the plants was highest in early May, shortly before the onset of flowering. In early May, the growth rate of corms was higher than that of the shoot.

scholarly journals Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda

2012 ◽  
Vol 30 (2) ◽  
pp. 317-325 ◽  
Author(s):  
R.C. Souza ◽  
A.C. Dias ◽  
M.R.A. Figueiredo ◽  
F.E.B. Obara ◽  
P.J Christoffoleti
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Leaf Number ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.

scholarly journals DIFFERENT SHADING NETS IN ESCAROLE GROWTH

2017 ◽  
Vol 26 (4) ◽  
pp. 584-595
Author(s):  
Daniela Meira ◽  
Daniele Cristina Fontana ◽  
Carla Janaina Werner ◽  
Thais Pollon Zanatta ◽  
Patricia Brezolin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Block Design ◽  
Weight Ratio ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Biological Productivity ◽  
Area Index ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of work was to verify the effect of different shading levels in escarole crop, during summer in the northwest of Rio Grande do Sul. The experiment was conducted at the Federal University of Santa Maria, Frederico Westphalen RS Campus, in 2015 with Escarola Lisa escarole cultivar. The experimental design was a randomized complete block design with three shading levels (0%, 30%, 50%), with six replications. Growth evaluation were performed in destructive manner every seven days, from transplant to harvest point. From the information obtained, traits were determined: leaf area, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, biological productivity, absolute growth rate, relative growth rate, net assimilation rate. The data obtained were analyzed by the statistical program Genes, the Tukey test at 5% of error probability. The shading level 30% provided greater leaf area, higher biological productivity and absolute growth rate. However, the leaf area ratio was higher when shading level 50% was tested. However, it can be said that the shading levels favor growth of escarole crop.

scholarly journals Growth of cowpea submitted to mineral fertilization and different doses of biofertilizer

2021 ◽  
pp. 321-328
Author(s):  
Mateus Alves de Sousa ◽  
Victor Sousa Avelino ◽  
Iolanda Maria Soares Reis
Keyword(s):  
Growth Rate ◽  
Seedling Emergence ◽  
Mineral Fertilizer ◽  
Northern Region ◽  
Stem Growth ◽  
Mineral Fertilization ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Small Producers ◽  
Different Doses

In the Northern region, the cultivation of cowpea is mainly carried out by small producers, who have little financial and technological resources to optimize and increase production. Therefore, the objective of this work was to evaluate the growth of cowpea subjected to mineral fertilization and doses of biofertilizer produced in domestic compost. The experiment was carried out in a protected environment, covered with a 50% shade screen, at the Federal University of Western Pará (UFOPA), Santarém PA, in 2017. Seeds were arranged in 5 L pots, containing 3.5 Kg of Yellow Latosol. For sowing, 3 seeds per pot were used and thinning occurred 7 days after seedling emergence, leaving only the most vigorous. The experimental design used was randomized blocks, with subdivided plots, where the plots were the doses of biofertilizer (50, 100, 150 and 200 mL plant-1 + mineral fertilizer) and the subplots, the time periods: T1 (0 to 20 days), T2 (24 to 33 days), T3 (37 to 47 days) and T4 (51 to 61 days), containing five repetitions. Plant height, stem diameter, absolute stem growth rate and absolute growth rate in stem thickness were evaluated. The greatest growth of cowpea was obtained in treatments with mineral fertilization. The dose of 200 mL plant-1 of the biofertilizer showed results close to mineral fertilization, in different vegetative stages. Cowpea plants, starting at 45 DAE, tend to stabilize their growth in diameter.

scholarly journals Morphological features of oat (Avena Sativa L.) shoots formation in the southern part of Ukraine

2020 ◽  
pp. 74-80 ◽  
Author(s):  
A. A. Ilina
Keyword(s):  
Growth Rate ◽  
Air Temperature ◽  
Effective Temperature ◽  
Weather Conditions ◽  
Growth Patterns ◽  
Average Growth ◽  
Absolute Growth Rate ◽  
Temperature Sum ◽  
Absolute Growth ◽  
The Absolute

Oats is essential for agricultural production and processing industry due to the unique biochemical composition of its grain. Thus, it is very important to study the biological and morphometric features of oats. The length and area of the plant's organs can establish a degree of comfort of growing conditions and determine during which period of plant's life the external weather conditions changed. Phytomers are basic repetitive functional units of the oat shoot. This paper presents the description and parameters of development of oat shoot metamers, namely, the identification of growth patterns of terrestrial vegetative metamers of oat shoots and their parts. The experiments were conducted in 2013, 2014 and 2018. The weather conditions of the specified years varied greatly – 2013 and 2014 were the most favorable in terms of humidification and precipitation, while 2018 was a very dry one. The paper determines the absolute and relative growth rates of the oat shoot internode paper and the maximum growth rate of each metamer in the linear phase. According to our observations, the absolute growth rate of oats was negligible and increased from 0.01 to 0.5 mm/d when the air temperature varied from 15 °C to 20 °C. However, when the air temperature reached about 20 °C, the absolute growth rate increased from 0.5 mm/d to almost 2 mm/d. We also found the effective sum temperatures under which the beginning and the end of the growth of each internodes take place. Thus, the first internode starts to grow the effective temperature sum of up to 117 °C is with the accumulated while the panicle starts growing when the effective temperature sum of up to 668 °C is accumulated. The growth of both the seventh internode and the panicle stops at the same time when the effective temperature sum of up to 1173 °C is accumulated. The ontogeny of oat shoots has a regular sequence of growth and development of terrestrial vegetative shoot metamers and their parts. The average growth duration of oat stem internode duting the years of research constituted 9 days for the first internode, 30 days for the seventh internode and 26 days for the panicle .

scholarly journals Growth of canola hybrids resistant and sensitive to herbicides

2020 ◽  
Vol 41 (6supl2) ◽  
pp. 2911-2922
Author(s):  
Miria Rosa Durigon ◽  
◽  
Joanei Cechin ◽  
Franciele Mariani ◽  
Gerarda Beatriz da Silva Pinto ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

Plant growth analysis is useful for determining adequate management practices and exploring the maximum yield potential of cultivars or hybrids. Canola hybrids with resistance to herbicides have been studied and registered for Brazilian conditions, as they improve weed management in canola crops. This study evaluated the growth of canola hybrids resistant to triazine or imidazolinone herbicides compared to a sensitive hybrid. The experiment was conducted using a completely randomized design, with four replications, in a bifactorial scheme using three hybrids and six sampling times. The canola hybrids used were Hyola 571CL (resistant to imidazolinones), Hyola 555TT (resistant to triazines), and Hyola 61 (sensitive to both herbicides). Height, leaf area, and dry matter of roots, leaves, stems, and shoots of the plants were evaluated at 14, 28, 42, 56, 70, and 119 days after emergence (DAE). The physiological indices absolute growth rate, leaf area ratio, specific leaf area, and net assimilation rate were calculated, and yield indices evaluated. Compared to Hyola 61, the Hyola 555TT hybrid showed lower values of leaf dry matter at 70 DAE, absolute growth rate up to 56 DAE, and net assimilation rate at 14 and 28 DAE, and a higher leaf area ratio at 56 DAE, whereas the hybrid Hyola 571CL presented lower leaf area and lower leaf dry matter at 70 DAE. At flowering, compared to Hyola 61, the hybrid Hyola 571CL presents lower leaf area, and the hybrids Hyola 555TT and Hyola 571CL have lower leaf dry matter accumulation. Differences in the growth of canola hybrids Hyola 555TT, Hyola 571CL and Hyola 61 do not cause differences in their grain yield.

Relationship between growth rate and the development of hollow stem in broccoli

2009 ◽  
Vol 60 (10) ◽  
pp. 995 ◽  
Author(s):  
M. Boersma ◽  
A. J. Gracie ◽  
P. H. Brown
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Dry Weight ◽  
High Growth Rate ◽  
Planting Density ◽  
Boron Deficiency ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Possible Cause

Boron deficiency is widely accepted as the dominant cause of hollow stem in broccoli (Brassica oleracea L. var. italica Plenck), although high growth rate has also been mentioned in the literature as a possible cause of the disorder. In this study, we investigated the role of growth rate and boron in the development of hollow stem. Two experiments were conducted with broccoli cv. Marathon, using planting density to manipulate growth rate. In the first experiment, plants were grown at 3 planting densities (19 512, 32 520, and 69 686 plants/ha) and either supplemented or not supplemented with foliar boron applications (0.35 kg B/ha) on two occasions. In the second experiment, broccoli plants at 2 planting densities (32 520 and 100 000 plants/ha) were treated in factorial combination from inflorescence initiation onwards with complete trace element fertiliser (1.5% B), 57% light interception, and paclobutrazol (480 g a.i./ha). The incidence and severity of hollow stem were assessed using digital image analysis and were found to increase with plant spacing but were not affected by boron application. The probability of hollow stem occurring increased with absolute growth rate in the first trial, but not the second. Absolute growth rate, measured as dry weight accumulation, was suppressed independently of planting density by the shading treatment, but did not influence the incidence or severity of hollow stem. The application of paclobutrazol did not influence absolute growth rate but reduced the severity of hollow stem at the lowest planting density. Our data support the hypothesis that the rate and pattern of growth are involved in the development of hollow stem, and that a boron deficiency is not the major causal factor.

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