Search results
Results from the WOW.Com Content Network
A large variety of mechanisms have been demonstrated to reinforce reproductive isolation between closely related plant species that either historically lived or currently live in sympatry. This phenomenon is driven by strong selection against hybrids, typically resulting from instances in which hybrids suffer reduced fitness.
Increased prezygotic isolation, which is associated with reproductive character displacement, has been observed in cicadas of genus Magicicada, stickleback fish, and the flowering plants of the genus Phlox.
Reinforcement, under his definition, included prezygotic divergence and complete post-zygotic isolation. [18] Servedio and Noor include any detected increase in prezygotic isolation as reinforcement, as long as it is a response to selection against mating between two different species. [4]
Costus plants: Costus allenii, C. laevis, and C. guanaiensis; [62] [63] C. pulverulentus and C. scaber [64] A unique case of post-zygotic instead of prezygotic isolation has been observed in both Gossypium and Gilia, suggesting that in plants, post-zygotic isolation's role in reinforcement may play a larger role. [3]: 361
Reproductive isolation is the process of species evolving mechanisms to prevent reproduction with other species. In plants, this is accomplished through the manipulation of the pollinator’s behavior (ethological isolation) or through morphological characteristics of flowers that favor intraspecific pollen transfer (morphological isolation).
Work from one species, the large-eared horseshoe bat (Rhinolophus philippinensis), shows that abrupt changes in call frequency among sympatric morphs is correlated with reproductive isolation. [9] A further well-studied circumstance of sympatric speciation is when insects feed on more than one species of host plant.
Prezygotic intrinsic and extrinsic differences have also been shown to be important in isolating hybrids from their parent species. In plants, pollinator mediated isolation resulting from changes in floral characteristics may be an important extrinsic prezygotic ecological barrier.
Three-spined stickleback fish have been a frequently studied species in ecological speciation.. Ecological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species.