What is the term used to describe the evolution of different species from a common ancestor?

Divergence

Evolutionary divergence illustrates how, from a common ancestor, species can follow different evolutionary paths in response to their environments or ways of life. This fundamental aspect of evolution is visible in the tree of life, where branches represent the separation of evolutionary lineages over time. A classic example is the evolution of mammals after the extinction of dinosaurs, which allowed varied ecological niches to be filled by new divergent species. Evolutionary divergence underscores the importance of adaptation and natural selection in the development of biodiversity over geological time.