Frederic Clements is widely credited with formulating the first comprehensive theory of ecological succession in the early 20th century. He developed the concept of succession as a directional process leading to a stable climax community, influenced by climate. His monograph "Plant Succession: An Analysis of the Development of Vegetation" (1916) was foundational in this field.A) Charles Darwin's work focused on evolution by natural selection, not specifically ecological succession. C) Sir A. Tansley coined the term "ecosystem" but is not primarily credited with coining the idea of ecological succession itself, although he contributed to ecological thought. D) Emberlin is not a figure widely recognized for coining the initial formal idea of ecological succession compared to Clements.