The high genetic variability among Xiphophorus species and capability of producing fertile interspecies hybrids allows inheritance of any observable trait to be followed into individual backcross hybrid progeny.
It has been reported that for diagnosis of systemic diseases, male pattern baldness (MPB), a clearly observable trait, can be used [ 1, 2].
Often this kind of investigation can be conducted by exploiting the naturally occurring variation among individuals, such as in a particular phenotypic (observable) trait in a population.
In conducting genetic studies, it is crucial to discover the degree to which the observable trait is attributable to the pattern of genes in the cells and to what extent it arises from environmental influence.
Darimont wrote that human predation is rapidly accelerating the rate of observable trait changes in commercially harvested species in the 20 January 2009 issue of the Proceedings of the National Academy of Sciences.
The phenotype, i.e. an individual's observable traits, is expressed in the metabolome.
Nevertheless, we acknowledge that all these estimation methods do not address selection on unobservable characteristics but, rather, they allow us to control for a wide variety of observable traits.
Plant phenotyping investigates how a plant's genome, interacting with the environment, affects the observable traits of a plant (phenome).
The manifestation of evolution at the organismal level is the phenotype, the set of observable traits inhering in an individual organism as a result of the interaction of heredity, environmental influences, and developmental processes.
The early cladists regarded efforts at such identification as speculatively beyond empirical analysis of immediately observable traits, so their reference to a "recent common ancestor" remained only an empty placeholder.
