  We investigate the evolution of mass segregation in initially sub-structured
young embedded star clusters with two different background potentials mimicking
the gas. Our clusters are initially in virial or sub-virial global states and
have different initial distributions for the most massive stars: randomly
placed, initially mass segregated or even inverse segregation. By means of
N-body simulation we follow their evolution for 5 Myr. We measure the mass
segregation using the minimum spanning tree method Lambda_MSR and an equivalent
restricted method. Despite this variety of different initial conditions, we
find that our stellar distributions almost always settle very fast into a mass
segregated and more spherical configuration, suggesting that once we see a
spherical or nearly spherical embedded star cluster, we can be sure it is mass
segregated no matter what the real initial conditions were. We, furthermore,
report under which circumstances this process can be more rapid or delayed,
respectively.
