Family size decomposition of genealogical trees.

We study the path of family size decompositions of varying depth of genealogical trees. We prove that this decomposition as a function on (equivalence classes of) ultra-metric measure spaces to the Skorohod space describing the family sizes at different depths is perfect onto its image, i.e. there is a suitable topology such that this map is continuous closed surjective and pre-images of compact sets are compact. We also specify a (dense) subset so that the restriction of the function to this subspace is a homeomorphism. This property allows us to argue that the whole genealogy of a Fleming-Viot process with mutation and selection as well as the genealogy in a Feller branching population can be reconstructed by the genealogical distance of two randomly chosen individuals.