You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
BBC_Television

Context:
David Attenborough was later granted sabbatical leave from his job as Controller to work with the BBC Natural History Unit which had existed since the 1950s. This unit is now famed throughout the world for producing high quality programmes with Attenborough such as Life on Earth, The Private Life of Plants, The Blue Planet, The Life of Mammals, Planet Earth and Frozen Planet.

Question:
When did the BBC Natural History Unit come into existence?

the 1950s