Why are all our voices different?

I think this question really comes down to “Why are all humans different from one another?” The reason that our fingerprints, faces, and many parts of our bodies are different are all the same. And I think that reason is “because everyone’s DNA is different.”

Then, why is everyone’s DNA different? I don’t know very much about biology or evolution, but I think it is because, this way, humankind can protect itself better. When humans first appeared, I think Earth was a very hard place to live. There were no doctors and no hospitals, so getting hurt was a big problem. And not every person is strong. So when a baby is born, it receives DNA from both its mother and its father, and that increases the variety in human DNA. I think that having more variety makes it easier for the group to survive.

So, because everyone’s DNA is different, each person’s mouth and throat are shaped differently, and that’s why our voices are different, too.

Original:

この質問は結局のところ「どうして人間はみんな違うの？」という質問に行き着くと思う。なぜなら、指紋や顔立ち、体のいろいろなところが違う理由も同じだからだ。そしてそれは「みんなのDNAが違うから」だと思う。では、なぜみんなのDNAは違うのだろう？私は生物学や進化の話はあまり詳しくないけど、人間一人一人のDNAが違って、声も違うのは、その方が人類を守れるからだと思う。人類が現れた時、地球はとても生きにくい場所だったと思う。お医者さんもいなくて病院もないから、ケガをしたら大変だ。そして人間は誰もが強いわけではない。だから赤ちゃんが生まれるときに、お母さんとお父さんの両方のDNAを受けついで、人類のDNAの多様性を増やした方が、グループとしての生存率が上がると思う。だからみんなのDNAは一人一人違うから、口や喉の形が違って、声も違うんだと思う。