**4. Biological evidences**

Biological evidence may be relevant to understanding human development and susceptibility to disease. With the improved nutritional status of many mothers around the world, the characteristics of their offspring—such as body size and metabolism—also changed. Their mother's prenatal response may generally respond to individuals so that they are more appropriate to the environment's expectations through the signals available in early life. If the mother is a smoker during pregnancy, it is possible that the third generation of her offspring will be smokers. Ironically, however, rapid improvements in nutrition and other environmental conditions may have adverse effects on the health of those whose parents and grandparents lived in poor conditions, as happened in World War II in Europe [29] and the famine in India early in the last century [30]. The full understanding of the patterns of human plasticity in response to early nutrition and other environmental factors will have implications for public health management.
