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For a simple system, mechanical isolation is equivalent to a state of constant volume and any process which occurs in such a simple system is said to be isochoric. [1] The opposite of a mechanically isolated system is a mechanically open system, [citation needed] which allows the transfer of mechanical energy. For a simple system, a ...
Mechanical isolation results from anatomical differences of a flower or pollinator preventing pollination from occurring. [44] For example, in the bee Eulaema cingulata, pollen from Catasetum discolor and C. saccatum is attached to different parts of the body (ventrally and dorsally respectively).
Mechanical or morphological isolation is a form of floral isolation where the characteristics of the flower prevents reproduction between species. These morphological differences primarily affect the positioning of reproductive structures within flowers and control the placement of pollen on the pollinator’s body to promote transfer within ...
Mechanical isolation also occurs in plants and this is related to the adaptation and coevolution of each species in the attraction of a certain type of pollinator (where pollination is zoophilic) through a collection of morphophysiological characteristics of the flowers (called pollination syndrome), in such a way that the transport of pollen ...
For radiative isolation, the walls should be perfectly conductive, so as to perfectly reflect the radiation within the cavity, as for example imagined by Planck.. He was considering the internal thermal radiative equilibrium of a thermodynamic system in a cavity initially devoid of substance.
Allopatric speciation (from Ancient Greek ἄλλος (állos) 'other' and πατρίς (patrís) 'fatherland') – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model [1]: 86 – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.
For example, differential fusion implies greater postzygotic isolation among sympatric species, as this functions to prevent fusion between the species. However, Coyne and Orr found equal levels of postzygotic isolation among sympatric and allopatric species pairs in closely related Drosophila. [8]
An example of gametic isolation involves the allopatric sea urchins have minimal bindin differences (bindin is a protein involved in the process of sea urchin fertilization, used for species-specific recognition of the egg by the sperm) and have insufficient barriers to fertilization.