While the two babies share the same DNA code, there is more to our genetics than just that. During development in the womb and after birth, our surroundings, exposures, and nutrition influence how our genes are expressed and how our bodies and minds develop. For example, two identical twins may have the same genes for height, but if one twin does not receive the same amount of nutrients while in the womb, it may be shorter than the other twin. We know also, that there are some changes to our genes that can happen during the embryonic period or during development. While this rarely happens, it makes it so that one identical twin may have a genetic condition, while the other twin does not. Our genetic code is a very large part of our genetic makeup, but there are other factors, genetic and environmental, that make us unique!