We study the evolution of embedded clusters .
The equations of motion of the stars in the cluster are solved by direct N-body integration while taking the effects of stellar evolution and the hydrodynamics of the natal gas content into account .
The gravity of the stars and the surrounding gas are coupled self consistently to allow the realistic dynamical evolution of the cluster .
While the equations of motion are solved , a stellar evolution code keeps track of the changes in stellar mass , luminosity and radius .
The gas liberated by the stellar winds and supernovae deposits mass and energy into the gas reservoir in which the cluster is embedded .
We examine cluster models with 1000 stars , but we varied the star formation efficiency ( between 0.05-0.5 ) , cluster radius ( 0.1-1.0 parsec ) , the degree of virial support of the initial population of stars ( 0-100 % ) and the strength of the feedback .
We find that an initial star fraction M _ { \star } / M _ { tot } > 0.05 is necessary for cluster survival .
Survival is more likely if gas is not blown out violently by a supernova and if the cluster has time to approach virial equilibrium during out-gassing .
While the cluster is embedded , dynamical friction drives early and efficient mass segregation in the cluster .
Stars of m \gtrsim 2 M _ { \odot } are preferentially retained , at the cost of the loss of less massive stars .
We conclude that the degree of mass segregation in open clusters such as the Pleiades is not the result of secular evolution but a remnant of its embedded stage .