An example of a polygenic trait is human skin color variation. Several genes factor into determining a person's natural skin color, so modifying only one of those genes can change skin color slightly or in some cases, such as for SLC24A5, moderately.
Case 1 â The Alleged Father has Recently Passed Away. If less than a week has passed since the deceased died, then if permission can be obtained, fingernail cuttings and a hair sample with root attached can be used to extract DNA samples to establish paternity. It is a more complex procedure than a buccal swab, but the DNA matching is just as accurate.
âLineage testing can trace your ancestry back to real existing people who carried that particular DNA type throughout prehistory until today,â explains Peter Forster, a geneticist at the University of Cambridge in the U.K. and cofounder of Roots for Real, a company in Cambridge that uses mitochondrial DNA tests to determine maternal ancestry.