I would like to begin this answer by clearing up some misconceptions about the Antarctic Treaty. The treaty was signed in 1959 and came into effect in 1961. The treaty doesn't say that nobody owns Antarctica, it explicitly states that it neither recognises nor disputes existing claims to the Antarctic.

The treaty mainly prohibits non scientific military activity on Antarctica, and allows for freedom of movement for everyone in Antarctica, and gives the country of origin jurisdiction over their people in Antarctica, irrelevant of whose territory they're on. It also has various other minor parts like stating "all treaty states will discourage activities by any country in Antarctica that are contrary to the treaty".

A later addition to the treaty in 1991 bans all mining in Antarctica for non-scientific purposes. The treaty effectively states Antarctica may or may not be part of a country, but no one can do anything there apart from science.

Most attempts at colonisation happened after the treaty was signed. In 1978 Emilio Palma was born in Antarctica, he was the son of the Argentine commander of Esperanza Base. His mother had been airlifted to Antarctica while pregnant in order to strengthen the Argentine claim to their Antarctic territory. There have since been 7 other people born in Esperanza Base. In the Antarctic Chilean town of Villa Las Estrellas there have been 3 births.

Esperanza and Estralles are the only two civilian settlements in Antarctica. In addition to them there are currently 42 permanent bases in Antarctica, however these bases don't have a permenant population and the people living there change. There is no one who has spent their entire life in Antarctica, so while there are permenant settlements there isn't a permenant population on Antarctica.