Due to the wide variety of appearance traits, it is easier to recognize individuals in a group of people. Facial appearance, height, pigmentation, hair morphology and density are just some of the anthropometric features that make up the physical phenotype. The accuracy of the genetic prediction of the phenotype depends on 4 factors:
- the heritability of a trait that determines the upper limit of the accuracy of its prediction;
- the capacity of the DNA variation analysis method, which determines the limit of explained heritability;
- the effectiveness of statistical methods that allow to read patterns of associations between genotypes and phenotypes;
- the size of available data sets used in predictive modeling.
Genomic prediction of physical appearance in connection with the determination of biogeographic ancestry, sex and age enables efficient selection of research hypotheses and faster solving of the most complicated criminal cases. High heritability of biometric traits (see monozygotic twins) suggests that a future genomic predictive system will potentially allow individual identification without the need to test a reference sample.