The high polymorphism in this system, which is composed of a high total number of alleles as well as allelic divergence on the sequence level, is thought to facilitate populations to persist in and adapt to natural habitats [ 5, 8].
'Sustainability' refers to the ability of a health service to provide ongoing access to appropriate quality care in a cost-efficient and health-effective manner [ 10] and implies a capacity to persist in, and adapt to, a changing environment.
Heckman and Rubinstein (2001) study the performance of General Educational Development GEDD) recipients and conclude that GED recipients' lower achievements in the labour market and their higher prevalence of criminal or risky behaviours can be attributed to a lack of the "ability to think ahead, persist in tasks and adapt to their environment" (Heckman and Rubinstein 2001, p. 146).
As a consequence, distinct populations may possess different potentials to persist in, and further adapt to, new habitats within an introduced range.
Species might also persist by adapting to local climate change in situ (Fig. 2B) (Skelly et al. 2007; Hoffmann and Sgro 2011).
But if greenhouse-gas emissions are brought under control, the planet's temperature goes up less dramatically, and New Yorkers persist in their efforts to adapt, the number of deaths could drop to a few hundred or so.
Whether M. ulcerans is primarily adapting to persist in a specialized environmental habitat, in arthropod hosts (34 ), or in chronic wounds of mammalian hosts remains to be determined.
1 Hepatotropic viruses adapted to persist in the liver have evolved to take advantage of this environment and trigger dysfunctional adaptive immune responses during acute (adenovirus) and chronic (hepatitis B virus [HBV] and hepatitis C virus [HCV]) virus infections of the liver.
During disease progression, the gastric environment changes and the infecting H. pylori strains must adapt to persist in a gastric habitat with increased pH, a new gastric cell composition and invasion of intestinal microbes.
Increased levels of adaptation to the mammalian gut environment may have resulted in species that persist in the gut and gradually adapt to a particular host (e.g. human).
For example, the infectious agent may be evolutionarily adapted to persist in an organ such as the CNS by bearing camouflage comprised of many epitopes that resemble and are crossreactive with the local host tissue.
