Search results
Results From The WOW.Com Content Network
An example of a botanical genetic polymorphism is heterostyly, in which flowers occur in different forms with different arrangements of the pistils and the stamens. The system is called heteromorphic self-incompatibility , and the general 'strategy' of stamens separated from pistils is known as herkogamy .
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).
It has also been determined that apostatic selection causes stabilization of prey polymorphisms due to the limitations of predators' behaviour. [7] Since the common prey type is more abundant, they should be able to produce more offspring and grow exponentially, at a faster rate then those with the rare morph since they are in much smaller numbers.
Trichomycterus davisi, for example, is an extreme case where the polymorphism was present within a single chimeric individual. [1] It has also been studied in alfalfa, [2] shrews, [3] Brazilian rodents, [4] and an enormous variety of other animals and plants. [5] In one instance it has been found in a human. [6]
Using Painter's technique, [18] they studied the polytene chromosomes and discovered that all the wild populations were polymorphic for chromosomal inversions. All the flies look alike whatever inversions they carry, so this is an example of a cryptic polymorphism. Evidence accumulated to show that natural selection was responsible:
Geographical polymorphism is where geographical isolation causes a divergence of a species into different morphs. A good example is the Indian white admiral (Limenitis procris) [clarification needed] which has five forms, each geographically separated from the other by large mountain ranges.
Agonistic behaviour is a result of evolution, [5] and this can be studied in a number of species facing different environmental pressures. Though agonistic behaviours can be directly observed and studied in a laboratory setting, it is also important to understand these behaviours in a natural setting to fully comprehend how they have evolved and therefore differ under different selective ...
For example, crocodiles possess a temperature-dependent sex determining polyphenism, where sex is the trait influenced by variations in nest temperature. [ 3 ] When polyphenic forms exist at the same time in the same panmictic (interbreeding) population they can be compared to genetic polymorphism . [ 4 ]