In ancient times, what was the scientific principle of blood betrothal?

When we watch costume dramas, there are basically scenes of blood betrothal, even in ancient times, but this blood betrothal has no scientific principle. That is, whether we are related or not, as long as we drop blood into the water, the blood will automatically merge together. If you want to know if there is blood relationship, only the Dan we are using now is the most accurate.

Blood dripping and bone dripping are two ways to recognize relatives in ancient times. Dropping a bone is dropping blood on a bone. If blood seeps into the bone, they are relatives. The other is blood, that is, take out a drop of two people's blood and put it in a bowl. If they blend together, they are relatives. If they are not fused, there is no blood relationship. One of the advantages of dropping blood to recognize relatives is that you can definitely drop a father. If you insist, you can lose a lot of dads. The disadvantage is that it is not necessarily your own father who can be integrated.

Blood is made up of many substances, and the most critical component is water. Because blood contains water, no matter whether they are related by blood or not, as long as they are put together, they will definitely merge. Someone once did an experiment to drop the blood of two unrelated people in the same cup, and the blood quickly dissolved together. If another person tries, the result is still the same. Finally, some medical experts point out that as long as blood is put into water, it can be dissolved together in theory, so there is no scientific basis for the ancient people to bloodletting and recognize their relatives, and of course it is even more unreliable.

In ancient times, the methods used to identify relatives usually had no scientific basis. At present, paternity testing is mainly based on human genetic markers for final screening and judgment. Our paternity testing technology is very mature, and the time for waiting for the result is very short.