On chapter 515 they mentioned all Kuja Tribe women always give birth to females.
How is this possible? Is there any explanation about this?
On chapter 515 they mentioned all Kuja Tribe women always give birth to females.
How is this possible? Is there any explanation about this?
No explanation is ever given beyond the word "mysteriously" but it isn't as ridiculous as it sounds.
In the real world, environmental factors such as the temperature and diet of the mother during pregnancy can affect the likelihood of a boy or a girl being born. Of course it rarely gets above 55-45 one way or the other, but in the unique environment of Amazon Lily it is possible that the odds of having a baby girl is completely overwhelming, to the point where no boy has ever been born on the island.
Unless the one piece author/s clarify the existence and origin of the Kuja tribe, there would be no accurate answer for this question. It happens most of the time in any anime and one piece is not an exception, let's just wait for any episodes where this tribe will be explain even more. For the meantime the succinct explanation of the Kuja tribe are as follows:
The Amazon Lily: http://onepiece.wikia.com/wiki/Amazon_Lily
The Kuja Tribe: http://onepiece.wikia.com/wiki/Kuja
The most simple answer would of course be "Magic" or anime logic.
However, when we look at the issue from a logical standpoint, we don't need to look at the tribe, but at the foreign countries, since the gender of the newborn is determined by the winning sperm, which either carries a female chromosome (X) or a male chromosome (Y).
Maybe the males in the foreign country only produce female sperm. Sperm production is affected by enviromental factors but this is unlikely, there'd be reports of that foreign country having female births (unless their females travel and get impregnated somewhere else as well). Keep in mind it's entirely possible that those reports could exist but the reader never gets told of any of this.
Most likely is that the tribe actually gets males born, but they are promptly killed (and no record of them is kept), much like real Amazon tribes did it.
Actually this might not be true. There may have kids being born as boys but due to some reasons the boys did not lived. In short, the elders are trying to prevent from boys being alive. I believe this is somewhat similar to what happened with Vincent(Hiei from Yu-yu Hakusho) wherein he was an outcast because of the tradition of having only female to live in their village.
Or maybe while they're out in the world, they did give birth to boys but was like 'oop! You're a boy; orphanage for you' and just only took home the girls. Remember, them getting pregnant requires them to leave the island OF WOMEN to go into the world OF MEN. So only people who left would know for sure. Who says they have to tell anybody they had a boy? Or that they were pregnant at all?