Many already know that a person’s physical traits are determined by genetic combinations from both parents, but these can be broken down into dominant and recessive categories. The former require only one copy of a dominant gene to outwardly express that trait, like brown eyes, dimples, naturally curly hair, etc.. However, for recessive traits to be expressed outwardly an individual must have two copies of a recessive gene, one from each parent. Examples include: grey / green / hazel / blue eyes, blonde hair, and height. Continue reading for more side-by-side photographs that show genetics at work. Click here for a few bonus images.