Phenotype refers to those traits or characters we observe in an organism. It has been proven that proven that heritable environmentally induced epigenetic modifications normally underlie the reversible and Tran’s generational alterations in an animal’s phenotype Most of these changes are inherited mitotically in somatic cells.
The environmental effects on the epigenome can have long-term effects in the gene expression. Environmental factors like nutritional supplements, reproductive factors, behavioral cues and low level radiation can lead to altered epigenetic programming in the prenatal and early post natal development of animals. Xenobiotic chemicals in the environment have some estrogenic characteristics which disrupt endocrine. The epigenome is most vulnerable to environment during embryogenesis DNA programming occurs in very early stages of development. In addition, toxins in the environment cause epigenetic changes to the DNA. These changes are passed on to subsequent generations despite lack of continued exposure. Roger Williams proved in the 1960s that genetic contributions were not enough to generate the difference observed in the phenotypes. Even twins who may have identical genetical make up usually exhibit very different habits when exposed to different environment settings. However, variations can occur without any significant changes in the environment.