Double eyelids, big eyes, high nose, big earlobes and long eyelashes are all dominant inheritance. First, when both parents have earlobes 1. Father AA, mother AA, then 100% of children have earlobes; 2. If the father is Aa and the mother is AA, then 100% of children have earlobes; 3. If the father is Aa and the mother is AA, then 100% of children have earlobes; 4. If the father is Aa and the mother is Aa, then 3/4 children have earlobes and 1/4 have no earlobes. Therefore, when both parents have earlobes, the child1516 has earlobes, and116 has no earlobes. Second, when both parents have no earlobes, father aa and mother aa, then 100% of children have no earlobes. 3. When the father has no earlobe and the mother has earlobe 1. Father aa, mother AA, child with earlobe100%; 2. If the father is aa and the mother is Aa, then 50% of the children have earlobes and 50% have no earlobes. So when the father has no earlobe, the mother has earlobe, and the child has earlobe for 3/4, 1/4 has no earlobe. When the father has an earlobe and the mother has no earlobe, the result is the same as the third one. The fetus is upside down in the mother's abdomen. Ears are like an upside-down fetus: head down, body up. In the part equivalent to the "fetus", it is called the earlobe, which is where girls get their ears pierced and hold the earlobe. The earlobe is the last growing part of the whole ear, which is formed at about the 32nd week of the fetus. The rest of the ear was exposed at 6 weeks, 8 weeks or 10 weeks. There are certain genetic factors in the earlobe, which have a certain relationship with ancestors. In addition, through its changes, we can see that some sick ears in the human body are also a heat dissipation organ. Observing the animal kingdom, we know that animals in the cold zone have small ears, while tropical animals have large ears, typically elephants. This difference exists even within the same species.

The earlobe is what remains after the heat dissipation function of the ear deteriorates. Modern people can live well without ear heat dissipation, so the gene without earlobe has been passed down.