Current Status
Examples of saltational evolution include cases of stabilized hybrids that can reproduce without crossing (such as allotetraploids) and cases of symbiogenesis. Evidence of phenotypic saltation has been found in the centipede and some scientists have suggested there is evidence for independent instances of saltational evolution in Sphinx moths. Some processes of epigenetic inheritance can also produce changes that are saltational. There has been a controversy over if mimicry in butterflies and other insects can be explained by gradual or saltational evolution. According to (Norrstrom et al. 2007) there is evidence for saltation in some cases of mimicry. The endosymbiotic theory is considered to be a type of saltational evolution.
Specific cases of homeosis in flowers can be caused by saltational evolution. In a study of divergent orchid flowers (Bateman and DiMichele, 2002) wrote how simple homeotic morphs in a population can lead to newly established forms that become fixed and ultimately lead to new species. They described the transformation as a saltational evolutionary process, where a mutation of key developmental genes leads to a profound phenotypic change, producing a new evolutionary linage within a species. Polyploidy (most common in plants but not unknown in animals) is considered a type of saltation. Polyploidy meets the basic criteria of saltation in that a significant change (in gene numbers) results in speciation in just one generation. Mammalian liver cells are typically polyploidal, but they are not part of the germ line.
Read more about this topic: Saltation (biology)
Famous quotes containing the words current and/or status:
“Absolutely speaking, Do unto others as you would that they should do unto you is by no means a golden rule, but the best of current silver. An honest man would have but little occasion for it. It is golden not to have any rule at all in such a case.”
—Henry David Thoreau (1817–1862)
“Recent studies that have investigated maternal satisfaction have found this to be a better prediction of mother-child interaction than work status alone. More important for the overall quality of interaction with their children than simply whether the mother works or not, these studies suggest, is how satisfied the mother is with her role as worker or homemaker. Satisfied women are consistently more warm, involved, playful, stimulating and effective with their children than unsatisfied women.”
—Alison Clarke-Stewart (20th century)