After more than 20 years of research on the subject, the ecologist Stephen Hubbell in 2001 proposed a neutral theory of ecology aimed at explaining the distribution and abundance of species in ecosystems. His theory is based on a few simple assumptions: the dynamics of ecological communities are stochastic and are a "zero-sum game“; the equivalence of all individuals of all species in their probability of giving birth, of dying, of dispersing, etc. The vocabulary used by Hubbell ("ecological drift,“ "stochastic process,“ "neutrality“) indicates a clear proximity to other neutral theories in the life sciences, such as Kimura‘s. Although Hubbell‘s theory is still the subject of scientific controversy, we think that this paradigm shift in ecology is sufficiently serious to be analyzed from an epistemological perspective. Thus, we will try to understand the impact of this theory on many traditional ecological concepts (niche, competition, equilibrium, etc.) and evaluate its claims in terms of explanation, prediction, and transformation of ecological dynamics. On a more general level, Hubbell‘s ambition is to unify ecological and evolutionary theories in order to create a new paradigm of macroscopic life phenomena. This perspective must also be submitted to a critical inquiry in order to underline the arguments for this unification and its difficulties. Eventually, we should assess the influence of neutral physical models (principle of inertia, stochasticity) on biological models.