As with many scientific advances there's rarely just one 'Eureka' moment. Behind every major human genetics landmark, including DNA testing, there's an entire history of ideas, developments, and advances that have played their part.
1865 - Although not recognised in his time, the field of human genetics takes its hat off to the Austrian monk Gregor Mendel. His love of study and garden peas gave us the laws of inheritance that are the foundation of DNA paternity testing. Fifty per cent of a child's traits come from the mother and fifty per cent from the father.
1920s - The four major blood types - A, AB, B, and O were identified in the early part of the 20th century. But it wasn't until the 1920s that scientists realised that the blood types were genetically inherited. It became possible to predict a child's blood type from an examination of maternal and paternal blood cells. Also if a parent was missing, it would be possible to work out his/her blood type from the child and the known parent.
1930s - It was discovered that an errant parent's blood type could be worked out from other proteins in the blood. Though like ABO blood typing the technology cannot conclusively identify individuals.
1953 - A really, really big moment in biology. Crick and Watson's paper on the structure of DNA.
1970s - The development of tissue typing with the discovery of the protein called human leukocyte antigen (HLA). It's present in all cells except red blood cells, and being highly variable between individuals, HLA testing for paternity rises to prominence.
1984 - British scientist Sir Alec Jeffreys introduces DNA fingerprinting to the world. Also in the mid 1980s restriction fragment length polymorphism (RFLP) is developed and becomes the basis for the first battery of genetic tests using DNA. The genetic material can be extracted from blood, spliced into highly variable sections that are similar amongst relatives, and as such are ideal for identifying relationships.
1990s - PCR (polymerase chain reaction) is where DNA is copied and amplified many times. It becomes the basis for paternity testing. It can even work with very small samples and the tests are much quicker than those based on RFLPs.
2000s and beyond - DNA testing becoming widely used for genealogical research and companies make DNA testing kits available to consumers. The future will more than likely see many other applications of the technology, and different types of DNA testing will no doubt be on offer.