Large bifurcation supports

The talk deals with a general problem of the bifurcation theory on the two-sphere. Consider a vector field with arbitrary degeneracies: complex singular points, multiple limit cycles and polycycles. What part of the phase portrait will bifurcate under a perturbation of this field, and what part will remain unchanged? Not only the degenerated parts of the phase portrait mentioned above will bifurcate; some generic parts will also. A highly nontrivial question arises: WHO BIFURCATES? The answer will be given in the talk based on a joint work with Natalya Goncharuk.