Epigenesis presents the exception to Mendal's law of inheritance. It basically presents the mechanism through which a gene shows alteration under the influence of environmental factors. Environment may have either a positive or a negative impact on the expression of genes.
It is a theory of genetics. It describes the concepts against pre-formation theory. It says that organisms get differentiation from an unstructured egg rather than simply enlargement of something preformed structure.
It also involves the concept of active and inactive genes. These causes alteration in gene expressions. It may cause change in phenotype despite any changes in genotype. It shows the impact of environmental factors on phenotype.
It is not simply the transfer of character from parents to offspring. It is the cumulative effects of environment and genetics in overall morphology development of an organism. These external factor makes this theory a complex one. There remains an ample scope of discussion about the expression of genes. It further provides a perplex nature to this theory.
For years we were taught Mendel's view that, barring mutation, genes were passed, unchanged, from one generation to...