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Showing 1 to 20 of 32 for “"Response to selection"”.
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Genomic response to selection for behavior
… vulpes) is a model of significant interest to social behavior genomics because of an experimental breeding project that began in the mid-20th century at the Institute for Cytology and Genetics in Novosibirsk, Russia. In this experiment, foxes acquired from fox farms were bred into two lines: …
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Phenotypic response to selection for protein in maize kernels
Long-term, divergent selection for protein concentration in maize grain has been conducted at the University of Illinois since 1896. Grain protein concentration in maize and other cereal crops is strongly associated with productivity, nutritional quality, and processing characteristics. Although …
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Response to Selection for Pupal Weight With and Without Assortative Mating in Tribolium Castaneum
Joint effects of pre-selection mating system (random: R; assortative: A), selection mating system (R;A) and percent truncation selected (20%; 50%; 0% (control)) were studied in a 2 x 2 x 3 factorial experiment with 5 replicates to examine direct response to selection for pupal weight (PW), and …
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Effects of Population Size, Selection Intensity and Linkage on Response to Selection for Oil in Maize
Made available in DSpace on 2014-12-10T17:47:18Z (GMT). No. of bitstreams: 1 6711921.pdf: 2172235 bytes, checksum: 117853d1238320ede59a56cba498c231 (MD5) Previous issue date: 1967
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Lowered reproduction efficiency as a correlated response to selection for increased post-weaning gain in laboratory mice
This study was initiated to determine the causes of lowered reproductive efficiency in mice selected for increased post-weaning gain. Four experimental groups were established: (1) Group C, the two control lines; (2) Group S, the four selected lines; (3) Group CS, the F₁ progeny from the 4 control …
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Beef on dairy economic selection index
The objective of this study was to create an economic selection index for a beef on dairy crossbreeding system. In an effort to improve overall performance in the system, the index aims to increase profitability. Crossbreeding a beef bull with a dairy female aims to add value to the resulting calf …
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Response to S1 recurrent selection and estimation of genetic parameters in effective population sizes of the BS11 maize population
<p>Recurrent selection is a cyclical breeding technique that has become popular in comprehensive maize improvement strategies. The magnitude of response in recurrent selection depends upon the modes of gene action and their frequencies in effective population sizes. We studied four effective …
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Resistance to Als-Inhibiting Herbicides in Common Ragweed, Foxtail and Horseweed
… molecular markers have been used in this study to investigate the evolution of cloransulam resistance in common ragweed, which appeared in the same year as cloransulam was commercialized. The results revealed that resistance to cloransulam in common ragweed evolved in response to selection by …
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Red fox genome assembly identifies genomic regions associated with tame and aggressive behaviors
… and conventional farm-bred populations to identify genomic regions associated with the response to selection for behavior. Analysis of the resequenced genomes identified 113 regions with either significantly decreased heterozygosity in one of the three populations or increased divergence …
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Regulation of floury2-mRFP expression in response to long term selection for grain protein concentration in maize
The Illinois Long-term Selection Experiment is the longest running continuous genetics experiment in higher plants in the world. Seven hundred and twenty-one cycles of divergent selection for grain protein and oil concentration have produced populations with the known phenotypic extremes for this …
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Divergent Selection for Water Conversion Ratio in Broiler Populations
… freshwater resources will be further strained to meet both human needs and agriculture applications. To ensure a water sustainable and food secure future, all aspects of agriculture must become more efficient. Two strategies were explored. The potential of improving water efficiency in broilers …
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Genetics, immunoresponsiveness, and disease resistance in chickens
… in this dissertation explored the effects of selection for antibody response on other immunological measures and on production traits. The role of thyroid hormones in antibody response was also studied. Selection for high (HA) and low (LA) antibody response to sheep erythrocytes altered …
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Selection for milk somatic cell count in laboratory mice
A bidirectional selection experiment for high and low somatic cell count (SCC) was conducted over 14 generations with two selected lines (high line = HSCC, low line = LSCC) of mice. Seven secondary traits (milk yield, total white blood cell count, percentage of phagocytic cells in blood, endotoxin …
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Female Ornamentation in the American Robin
… the subject of much research effort, and sexual selection is recognized as the leading explanation for their evolution. The expression of ornamental traits in females has received little study until recent decades. Female colouration has been considered a non-adaptive, correlated response to …
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Heterogeneity of within-herd variances for conformation and its relationship to various herd parameters in the U.S. Holstein population
… classification records were analyzed to examine heterogeneity of variances for conformation in the U. S. Holstein population. Data set I included records for final score and linear descriptive traits on cows scored from 1983 through 1986. Results indicated a strong negative correlation …
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Investigating the heritability of resistance fueling copy number variation in glyphosate resistant Amaranthus palmeri
Gene copy number variation (CNV) can arise as a response to selection pressure from the environment. Herbicide is one selective agent targeting and promoting the evolution of resistance in agricultural weed populations. In Amaranthus palmeri, CNV of the EPSPS gene, the target of glyphosate …
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Evolution of floral and mating system variation in Camissoniopsis cheiranthifolia (Onagraceae): An evaluation of patterns and processes
… divergence in key floral traits expected to be associated with variation in the relative importance of outcrossing vs. self-fertilization. I combined geographic surveys of floral variation with genetic estimates of the proportion of seeds outcrossed (t) and confirmed that t covaried with …
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The Resource Environment and Microbial Associations Mediate Adaptation to Environmental Heterogeneity in Drosophila Melanogaster
Identifying the putative environmental factors that influence the adaptive outcomes ofpopulations as they respond to heterogeneity remains a major focus of evolutionary biology. The ability to observe the genomic and phenotypic evolution of populations over rapid timescales has enabled a deeper …
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Genetic constraints on the evolution of sexual size dimorphism
In this thesis, I use an artificial selection experiment and multivariate simulation modelling to study some basic questions concerning the evolution of sexual size dimorphism (SSD). Fecundity selection is often suggested as the main causal factor underlying the prevalence of female-biased SSD, but …
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Genetics of initial imprinting responses: selection, and heterosis
Domestic chicks were tested for initial response, approach, and stay-near tendencies during one 5-minute test exposure to a distant audio-visual 1mprinting apparatus. Significant interline differences demonstrated genetic variation. A bidirectional selection program was initiated with time to …
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