The year 2019 marks the 100th anniversary of the death of Ernst Haeckel, a German zoologist, artist, and philosopher of science, who defended and supplemented Charles Darwin's system of theories regarding the mechanisms of biological evolution. We briefly recapitulate Haeckel's remarkable career and reproduce the Laudatio read by the President of the Linnean Society of London (1 July 1908), when Haeckel was awarded the Darwin-Wallace Medal. Finally, we summarize the importance of Haeckel's original concepts, insights, and theories with reference to our current knowledge in the areas of evolutionary biology, molecular phylogenetics, systematic zoology, and philosophical issues today.
Keywords: Charles Darwin; Darwin–Wallace Medal; Ernst Haeckel; Evolution.