Adaptation
Parasites infect hosts that exist within their same geographical area (sympatric) more effectively. This phenomenon supports the "Red Queen hypothesis—which states that interactions between species (such as host and parasites) lead to constant natural selection for adaptation and counter adaptation." The parasites track the locally common host phenotypes, therefore the parasites are less infective to allopatric (from different geographical region) hosts.
Experiments published in 2000 discuss the analysis of two different snail populations from two different sources- Lake Ianthe and Lake Poerua in New Zealand. The populations were exposed to two pure parasites (digenetic trematode) taken from the same lakes. In the experiment, the snails were infected by their sympatric parasites, allopatric parasites and mixed sources of parasites. The results suggest that the parasites were more highly effective in infecting their sympatric snails than their allopatric snails. Though the allopatric snails were still infected by the parasites, the infectivity was much less when compared to the sympatric snails. Hence, the parasites were found to have adapted to infecting local populations of snails.
Read more about this topic: Parasitism
Famous quotes containing the word adaptation:
“The real security of Christianity is to be found in its benevolent morality, in its exquisite adaptation to the human heart, in the facility with which its scheme accommodates itself to the capacity of every human intellect, in the consolation which it bears to the house of mourning, in the light with which it brightens the great mystery of the grave.”
—Thomas Babington Macaulay (1800–1859)
“Whatever there be of progress in life comes not through adaptation but through daring, through obeying the blind urge.”
—Henry Miller (1891–1980)
“In youth the human body drew me and was the object of my secret and natural dreams. But body after body has taken away from me that sensual phosphorescence which my youth delighted in. Within me is no disturbing interplay now, but only the steady currents of adaptation and of sympathy.”
—Haniel Long (1888–1956)