Let S be a topological
semigroup and let X be a left translation invariant, left introverted closed subspace of
CB(S). Let m and μ be elements of X∗, where μ(f) =∫f dμ for f in CB(S) and μ is
a measure on S which lives on a suitable set. It is shown that the evolution and
convolution of m and μ coincide. The same argument carries over to prove that if
X ⊂ W(S), then the evolution and convolution of m and n in X∗ are the same
(a known result). The topological invariance of invariant means on X∗ is
discussed.