Here's the breakdown:
* Origins: Tanka poems originated in Japan around the 7th or 8th century. They were initially called "uta" (song) and were closely tied to traditional Japanese music and courtly culture.
* Early Forms: Early tanka forms were longer and less structured, but they gradually evolved into the familiar 5-7-5-7-7 syllable format we know today.
* Development: The Heian period (794-1185) saw a significant development of the tanka form, with poets like Lady Murasaki Shikibu (author of *The Tale of Genji*) writing renowned tankas.
* Influence: Tanka poetry continued to be popular throughout Japanese history, influencing other forms of literature and art.
Therefore, it's more accurate to say that tanka poems emerged organically as a result of the evolution of Japanese poetry.