As a component of a coadapted
complex, theory evolves in the direction of further justifying government's often increasing regulatory mandate for securing food safety.
This is contrary to models of speciation that rely on a random disruption of well coadapted
traits that are continually buffered by stabilizing selective pressures within species (Carson 1982, 1985).
This Evolutionary Hypothesis proposes that different coadapted
gene systems would have evolved independently in each parental genome.
Despite areas of hybridization, the abrupt discontinuity between the species, both in song and genetics, indicates that selection acts to maintain coadapted
gene complexes in the two species.
This clearly suggests that the coadapted
gene complexes controlling these associations were properly sampled and that the selection of this core collection was adequate in this regard.
The coadaptation hypothesis predicts that FA arises from the disruption of coadapted
gene complexes, which occurs in response to hybridization, and as a result hybrids should have higher fluctuating asymmetry (Clarke 1993).
Just as epistasis can be the basis for "coadapted
gene complexes" within a population, genotype-by-environment interactions can be the foundation for adaptations realized by organisms living in different environments.
Hayward and Breese (1993) described the genetic structure of inbred cereal landraces as "stable mixture of coadapted
genotypes having different and complementary requirements for resources such as nutrients and light, and thus escaping competitive elimination".
Long-distance dispersal may take the individual to a habitat to which it is less adapted (Dias and Blondel 1996) and/or cause it to produce less fit offspring when reproducing with a philopatric individual, due to break down of coadapted
gene complexes (Shields 1982; Waser and Price 1994).
Genetic revolution and the origin of coadapted
genomes in parthenogenetic strains.
Intentional inbreeding may then be favored by the evolution of coadapted
gene complexes and/or adaptations to local environmental conditions (Mayr 1963, Moll et al.
With nonadditive maternal inheritance, selection affecting the variance and covariance of traits could favor the divergence of the population into distinct groups (i.e., polymorphism; Wade 1998) or may fix the population for a single coadapted
set of maternal and offspring characters.