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In biology, polymorphism [1] is the occurrence of two or more clearly different morphs or forms, also referred to as alternative phenotypes, in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating).
The size of the aureole depends on the heat of the intrusion, its size, and the temperature difference with the wall rocks. Dikes generally have small aureoles with minimal metamorphism, extending not more than one or two dike thicknesses into the surrounding rock, [51] whereas the aureoles around batholiths can be up to several kilometers wide.
Phase transitions (phase changes) that help describe polymorphism include polymorphic transitions as well as melting and vaporization transitions. According to IUPAC, a polymorphic transition is "A reversible transition of a solid crystalline phase at a certain temperature and pressure (the inversion point) to another phase of the same chemical composition with a different crystal structure."
Polymorphisms can be identified in the laboratory using a variety of methods. Many methods employ PCR to amplify the sequence of a gene. Once amplified, polymorphisms and mutations in the sequence can be detected by DNA sequencing, either directly or after screening for variation with a method such as single strand conformation polymorphism analysis.
The difference between producing a stable vs. metastable entity can have important consequences. For instances, having the wrong crystal polymorph can result in failure of a drug while in storage between manufacture and administration. [11]
There is, for example, a polymorph-ratio cline in D. robusta along an 18-mile (29 km) transect near Gatlinburg, TN passing from 1,000 feet (300 m) to 4,000 feet. [55] Also, the same areas sampled at different times of year yielded significant differences in the proportions of forms.
The difference in grade between two locations is called the metamorphic gradient. Planes that connect points with the same metamorphic grade are called isograds. The secant lines of isograds with the surface form lines on a geologic map. Changes in mineralogical composition in a terrane reflect differences in metamorphic grade of the rocks.
A dragonfly in its final moult, undergoing metamorphosis, it begins transforming from its nymph form to an adult. Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. [1]