Paternity testing has undergone many changes over the decades. We can trace its course beginning with the most simple technique in which blood groups of father and child where compared and move on to the present day method which involves using DNA.
Paternity testing with Blood Groups
The blood grouping system was used for a while to determine paternity. This was one of the earliest methods used but has today been phased out completely. Blood groups cannot be used to pin point a father as the biological father of a child. A child cannot have a blood group antigen that one or both of his parents does not have. But a father and child sharing the same blood group does in no way indicate that that man is the real father of the child- millions of men would in fact, have the same blood group and could all be potentially the child’s real dad. The blood group system to determine paternity is thus, only useful to exclude individual as being the biological dads.
Moreover, with the ABO blood group system, there are only 4 different blood groups and groups A and O are very common. The implications of this are clear: even if the father’s blood group matches that of the child, it does not conclusively mean he is the biological father unless the mother is certain there is no other possibility. Paternity testing with blood groups has become obsolete as it is not half as reliable and practical as the DNA paternity test.
Blood groups are a thing of the past
Blood groups are no longer used for paternity testing. Here is how paternity tests are carried out in this day and age and how samples are collected. Read more.