Most individuals have a general understanding of genetics and that our external characteristics appear to be the way they are due to the makeup of our genes. However, there are additional factors that determine which set of genes are expressed.According to the medical department at the University of Leicester, these factors can be evident as epigenetics; displaying the change in expression without a change in the DNA sequence. In reality, this channels another level of genetic control in addition to a person’s DNA sequence, including several external changes that can impact gene function through, environmental factors, diseases, diet and lifestyle (Horsager 2016).The external environmental factors can affect genes which can influence disease, offspring changes and trauma-related stress and anxiety. Epigenetics The whole concept of epigenetics began in the early in the 1940s when Dr. Conrad Waddington brought human developmental biology and genetics together as the field we know as epigenetics. The term was derived from Greek roots and word “epigenesis” which originally portrayed the effects of genetics and embryological growth (Felensfield,2014). Waddington’s goal with epigenetics was to present insight into gene-environment interactions that influenced genetic development. This British biologist published a paper in an “evolution” journal in which he succeeded in demonstrating the major link between the character development of individuals in response to environmental factors. The study of epigenetics has continued for the past century and has been proven to be linked with the evolution and development of humans. During the past fifty years, the term ‘epigenetics” has undergone an evolution that has extensively increased our knowledge of gene expressions in eukaryotes. This has led to the working definition of epigenetics as “the study of mitotically and/or meiotically heritable changes in gene function that cannot be explained by changes in DNA sequence” (Riggs et al. 1996;).Nutrition and lifestyle effects on development Nutrition has been the one of the greatest environmental influence on babies in the womb, during infancy and continues to remain essential throughout the first years of life. (the urban child institute, 2011) According to the national institute of health, a proper diet and the balance of nutrition in certain periods of life is critical for proper and normal brain development. Malnutrition for nutrients such as iron and iodine can impair motor and cognitive development. As well as other nutrients such as choline, folic acid, and zinc have been linked specifically to childhood development. Nutrition plays a huge role in daily life leading up to development which allows it to work inverse depending on the environment of the individual ( World Health Organization and Food and Agriculture Organization of the United Nations,2004)For example, Swedish scientists recently conducted experiments examining whether nutrition affected the death rate associated with cardiovascular disease and diabetes and if these effects were passed from parents to their children and onto grandchildren (Kaati et al., 2002). These researchers estimated how much food individuals consumed by examining harvests records and food prices in Sweden, dating as far back as the 1890s. Swedish researchers found that if a father did not have enough food available to him during a critical period in his development just before puberty, his sons were less likely to die from cardiovascular disease. Remarkably, death related to diabetes increased for children if the food was plentiful during this critical period for the paternal grandfather, but it decreased when excess food was available to the father. (Kaati et al., 2002). These studies and findings suggested that diet and lifestyle lead up to change in genes that are passed down through future generations. Environmental conditions and its effects on offspring As diet and nutritional value majorly affects chances of diseases in individuals, similarly, other environmental conditions including toxins and hormonal changes can also shape and affect future offspring. Although many believe that new offspring and embryos are rebuilt from scratch recent studies have shown that offsprings are built with previous tags linked from reproductive cells (Desai, 2005). This genetic information from the phenotype is also passed down from generation to generation, a process called epigenetic inheritance. This process goes against traditional inheritance which happens through DNA coding passing from the parent to the offspring. Epigenetic inheritance is the ideology of the parent’s experiences getting passed down and as epigenetic tags and going on to future generations. Through epigenetic inheritance, most parental experiences may be passed down to generation while the epigenome remains flexible depending on environmental conditions without changing the DNA code (Martienssen, 2015). An ideal example of this common issue in today’s society is the effect of famine and drought during pregnancy. Processes, where stress or critical period of development has long-term effects on individuals, is called “programming”. Throughout evolution and the development of humans, famine and drought were the two most common environmental caused stresses. According to the Department of Obstetrics and Gynecology at the Harbor-UCLA Medical Center “Our laboratory has performed studies among pregnant rat and sheep in which we simulate drought conditions via maternal dehydration and famine conditions via nutrient restriction. Maternal dehydration results in low-birth-weight offspring, which demonstrate gender-specific plasma hypernatremia and hypertonicity and arterial hypertension. The gestational nutrient restriction also resulted in low-birth-weight offspring. If permitted rapid catch-up growth by nutrient availability, these offspring demonstrate evidence of increased body weight and body fat and leptin resistance as adults.” These studies indicate that epigenetic and environmental conditions may potentiate and prevent problems during the neonatal period and ignite problems for development.Historical trauma effects on generationsUnder normal environments and circumstances, fear is triggered by a natural fight or flight response that allows us to react quickly to potentially threat our surroundings and our environments. However, having excessive or irrational fear is seen as a maladaptive response. Having an unwanted fear of certain situations and objects are known as certain phobia which can cause distress and anxiety. Nevertheless, it is important to understand that recent studies have verified that automatic fear and phobia is inherited rather than taught by performing studies done on mice. According to Nature neuroscience study done by professors at University College London “researchers exposed mice to the smell of cherry-blossom in a panic-inducing situation. The so-called odor fear conditioning makes the mouse associate the cherry-blossom smell with a traumatic event to the point that a fear response occurs when they encounter the odor on its own. When female mice acquired this form of PTSD before conception, the next two generations of mice still exhibited “behavioral sensitivity” towards the cherry-blossom odor despite never being exposed to it before” These results allow us to understand the importance of how past experiences of our parents before conceiving offsprings show great influence on how the function of the nervous systems can be continued through generations. Conclusion In defiance of the field of Epigenetics being relatively new and depreciated it is important to understand that the increase in the research conducted towards epigenetics is greatly beneficial to childhood development as it has the potential to prevent issues such as the increase in diet-related illnesses, neonatal changes and mental health amongst children worldwide. Overall it is apparent that with the increase in the study of epigenetics and the beneficial change in our environment it can positively impact child growth and set a path for positive conditions to create successful and innovative individuals for our future society.