Human genetics is a major branch of physical anthropology that studies the inheritance of biological traits, genetic variation, and evolutionary relationships among human populations. Since controlled breeding experiments cannot be performed on humans for ethical reasons, physical anthropologists rely on several indirect methods to study human heredity. These methods help in understanding the transmission of genetic traits, the causes of inherited disorders, population diversity, and the role of genes in human evolution. The major methods of human genetic study are as follows. The pedigree method is one of the most important methods used in human genetics. A pedigree is a family tree that records the inheritance of specific traits across several generations. Special symbols are used to represent males, females, affected individuals, and marriages. By analyzing pedigrees, researchers can determine whether a trait is dominant, recessive, autosomal, or sex-linked. This method is particularly useful in studying hereditary diseases such as hemophilia, color blindness, Huntington's disease, and cystic fibrosis. It also helps in genetic counseling by predicting the probability of genetic disorders in future generations. The twin method is another valuable approach for studying the influence of heredity and environment. Twins are of two types: monozygotic (identical) twins, who develop from a single fertilized egg and possess nearly identical genetic material, and dizygotic (fraternal) twins, who develop from two separate eggs and share about 50 percent of their genes. By comparing similarities and differences between these two types of twins, anthropologists can estimate the relative contribution of genetic and environmental factors to physical, behavioral, and psychological