The term phenotype is derived from the Greek words phainen (“to show”) and typos (“type”). A phenotype is essentially the composite of an organism’s observable characteristics and traits, including the morphology, development, biochemical and physiological properties, behavior, phenology, and various products of behavior of the organism. Phenotypes come from the expression of an organism’s genes, as well as the influence that the environment extends on the organism and the interactions between environment and organism.
The genotype of the organism contains the inherited “instructions” that will dictate its genetic code. However, not all organisms with the same genotype will look or act the same way, as the environmental and developmental conditions that the organism has been subjected to. Also, it is important to note that not all organisms that look alike have the same genotype.
In 1911, the Danish geneticist Wilhelm Johannsen proposed a distinction between genotypes and phenotypes in order to make clear the difference between the heredity of the organism and what this heredity produces. Johannsen’s genotype-phenotype distinction is very similar to that proposed by an evolutionary biologist, August Weismann. In his distinction proposal, Weismann stated the differences between the germ plasm (which is involved with heredity) and the somatic cells (referring to the body).
While it might seem that anything that depends on the genotype is a phenotype (including molecules such as proteins and the RNA). This is because most molecules and structures that are coded by the genetic material are not visible in the appearance of the organism, but they are observable and can be considered as part of the phenotype. Human blood groups are an example of an invisible yet observable phenotype.
This category contains scientific information on phenotype, the composite of an organism’s observable characteristics and traits, including the morphology, development, biochemical and physiological properties, behavior, phenology, and various products of behavior of the organism.
Saunders R.L., 1981: Evidence of adaptive poly genic variation between 2 populations of atlantic salmon salmo salar native to tributaries of the southwest miramichi river new brunswick canada. Canadian Journal Of Fisheries & Aquatic Sciences: 321-333 Breeding experiments were conducted to test the hypothesis that spatial homeostasis in growth and proximate composition and geographic variation [...]
Williams W.A., 1982: Evaluation of yield components as selection criteria in barley hordeum vulgare breeding. Crop Science: 927-931 A combination of statistical procedures was used to determine which yield components were most likely to be effective selection criteria for yield improvement in barley (H. vulgare L.). The procedures included the following: simple phenotypic correlations between [...]
“Gaidarska V., 1985: Evaluation of the realized genetic gain of the black and white population. Zhivotnov””dni Nauki: 13-17 A study was conducted to evaluate the realized genetic gain (.Delta.g) by the Black and White population for the period 1978 to 1982 in ten cooperative farms in the district of Sofia Evaluation of the realized genetic [...]
Epkenhans P., 1986: Evaluation of the breeding value of dual purpose bulls for meat production using progeny performance from fattening and slaughtering operations. Arbeiten Aus Dem Institut Fuer Tierzuchtwissenschaft Der Rheinischen Friedrich Wilhelms Universitaet Zu Bonn: Ii, 1-146 Data from 241 combined dairy cattle-fattening operations and 60 slaughtering operations were collected in order to determine [...]
Tsvetanov V., 1988: Evaluation of the additive maternal and total heterosis effect in interbreed hybridization. Genetika I Selektsiya: 82-89 Genetic-statistical models elaborated by Gardner and Eberhart (1966) were used in evaluating these effects. For the purpose of optimizing their adequacy for the definite conditions of the branch, the fixed models applied were replaced by mixed [...]
Johnson L.P., 1983: Evaluation of linearized type appraisal system for holstein cattle. Journal Of Dairy Science: 325-331 Data from a Holstein linear type appraisal project for traits suggested by the National Association of Animal Breeders were analyzed to evaluate genetic statistics of linear type. Data were scored by 28 classifiers as an adjunct to the [...]
Kuck A., 1981: Evaluation of a linear type program in holsteins. Journal Of Dairy Science: 1610-1617 Data of 18 traits in the linearized type appraisal program of Midwest Breeders Cooperative were analyzed. Mean scores ranged from 25.1-32.8, with scoring 1-50, except for disposition (mean 2.0 and scoring 1-3) and milkout (mean 2.1 and scoring 1-4). [...]
Henningsson T., 1979: Evaluating performance tested beef bulls for daily gain by best linear unbiased prediction. Acta Agriculturae Scandinavica: 393-401 Best linear unbiased prediction (Blup) methods were used to evaluate 805 and 272 performance-tested Hereford and Charolais bulls for daily gain at central testing stations. Sire and error components of variance estimated from the Swedish [...]
Mcclintock A.E., 1985: Evaluating dairy sires for conformation of their daughters use of 1st classification records. Australian Journal Of Agricultural Research: 509-526 Type classification records for 18,132 Australian Holstein-Friesian heifers were analyzed. These consisted of 27 traits scored in 3 or 6 categories, from 3 rounds of classification between 1981 and 198 Only first lactation, [...]
Spencer J.L., 1983: Estimation of variance components and heritability in populations affected by disease lymphoid leukosis in chickens. Theoretical & Applied Genetics: 317-322 The effects of disease, particularly when congenitally transmitted, on variance components and heritability were studied. Observations on lymphoid leukosis, a congenitally transmitted, viral disease of chickens, were used as the basis of [...]