O Tannenbaum O Tannenbaum "" (; "O fir tree", English: "O Christmas Tree") is a German Christmas song. Based on a traditional folk song, it became associated with the traditional Christmas tree by the early 20th century and sung as a Christmas carol. The modern lyrics were written in 1824, by the Leipzig organist, teacher and composer Ernst Anschütz. A "Tannenbaum" is a fir tree. The lyrics do not actually refer to Christmas, or describe a decorated Christmas tree. Instead, they refer to the fir's evergreen quality as a symbol of constancy and faithfulness. Anschütz based his text on a 16th-century Silesian
Emmanuel David Tannenbaum subsequently devoted his research to studying various problems in evolutionary dynamics using quasispecies models. His seminal work centered on the key question of the evolutionary advantages of sexual reproduction. Tannenbaum demonstrated a strong selective advantage for sexual reproduction with fewer and much less restrictive assumptions than previously considered. Closely related to this line of reasoning, was the original work by Tannenbaum and James Sherley on the immortal strand hypothesis. Tannenbaum also proposed a pioneering theory of why higher organisms need sleep. Towards the end of his life, he proposed a new approach to anti-stealth technology based on the theory of