Term proposed by J. H. Connell in 1980 to describe one possible reason for observed differentiations in niches. Competing species may be less fit than a species which avoids competing because it occupies a fundamental niche which does not overlap theirs. Natural selection may then favour the non-competing species; its population increases and those of the competing species decrease. The observed differentiation is then the result of past competition and to explain it in this way is to invoke the ghost of competition past.
http://academics.rmu.edu/~dress/Documents/Ecology/Ecology%20L16%20competition2.pdf. The concept explained in more detail.
Subjects: Ecology and Conservation.