As we know, the imagination of Dragon Ball, however popular, it is subjected to a constant wave of confusion, dictated above all by a series of narrative inconsistencies that have repeatedly left fans perplexed. In this regard, we take this opportunity to definitively clarify a very controversial point in the history of the manga.
Many times, in fact, fans have submitted some doubts about some genetic traits, both in the absence of Goten's tail since birth and in the blue hair of the little Trunks. In an interview dating back to 2003, Akira Toriyama answered the question in question stating that it is a matter of "recessive genetic traits". Writer Derek Padulait further clarifies the issue by adding the following:
"Both Goten and Trunks were born without a tail. In fact, recessive genes can sometimes appear even with a copy, that's why what should be brown in theory turns blue [come nel caso degli occhi azzurri]. So why, instead, does Gohan have a tail? Saiyan, in fact, has a very rare expression of the tail gene, unlike the familiar hybrid traits - Saiyan and terrestrial blood - which have instead manifested themselves with a normal genetic expression. This, in conclusion, means that most children born from an intersection will not have a tail, with a few exceptions. "
Gohan, therefore, is the exceptional result of the combination of genes, which is why the presence of a tail at birth is a symptom of a particularly rare case. This also fits with the intentions of Toriyama himself who wanted to make Gohan the real protagonist, accentuating the Saiyan traits of the character.
Why does Gohan have a tail, but Goten and Trunks do not? According to Toriyama, "tails are a recessive genetic trait." Saiyan tail genetics is a popular subject among the Dragon Ball fandom, but there’s a lot of misinformation out there. Please share this! #DragonBallCultureDaily pic.twitter.com/uzHQAJKcHh- Derek Padula (@DerekPadula) May 23, 2020