More often than not, great scientific journeys start with a paradox. For instance, Charles Darwin was intrigued by the non-reproductive castes of some insect species, to the extent of considering them a major obstacle to his theory of evolution by natural selection. In the sixth edition of The Origin of Species he wrote:

The search for a resolution to Darwin’s sterile castes paradox produced a wealth of research that mainly took off in the 1960s and 1970s and that from the elegant William D. Hamilton’s formula (also known as Hamilton’s Rule) and John Maynard Smith’s concept of kin selection, through Edward O. Wilson’s impressive Sociobiology: The New Synthesis, has led us nowadays to Reproductive Skew Theory.

More than 80 years after Darwin’s formulation of his non-reproductive castes paradox, the ecologist George Evelyn Hutchinson (1959) was able to turn the apparently most trivial of questions: ‘Why are there so many kinds of animals?’ into a major evolutionary ecological paradox leading to the study and better understanding of the ecological processes, such as interspecific competition, that determine the structure and dynamics of natural communities. Over evolutionary time, such ecological processes can eventually produce character displacement and, ultimately, speciation.