There has been vigorous debate regarding the roles of drift and selection in the evolution of genes, genomes and organisms [71], [72], but the mechanisms by which genomic changes result in evolutionary novelties remain unclear.
In at least some genomes, polyploidization is followed by extensive genomic change resulting in the silencing and elimination of duplicated genes [1].
The consequences of hybridization at the molecular level in fungi are unknown, but in plants they include both genomic and epigenetic changes resulting in the alteration of gene expression and the evolution of new phenotypes [1], [2], [20], [21].
Metaplasia undergoes further genomic and phenotypic changes, resulting in gastric dysplasia and finally adenocarcinoma [ 3].
These estimates of GHG reduction are conservative as improved DM digestibility in –RFI cattle and improved accuracy and rate of genetic change resulting from genomic enhanced breeding values were not considered.
To focus our discussion, we do not include genomic studies of protein regulation changes resulting from OP exposure or the MS of OP compounds.
In addition, genomic changes can result from the tissue culture procedures that are required to transform several plant species, leading to epigenetic and heritable (somaclonal) variation of nucleic DNA [8] [10].
Those changes were so severe that 10 population doublings after they became detectable by flow cytometry, the apoptotic pathways triggered by those genomic changes had resulted in rates of cell death that were higher than rates of cell proliferation.
These genomic changes often result in novel phenotypes, some that are intermediate between parentals, some that represent novel combinations of parental features, and, finally, others that are extreme or transgressive compared to those of the parental species.
For non-melanoma skin cancer (NMSC), these changes are classically defined as occurring in stages: (a) initiation, involving DNA damage leading to mutations, (b) promotion, which involves proliferation and inflammation, and (c) progression, involving additional genetic mutations or structural genomic changes that result in malignancy.
