  Evolutionary events such as incomplete lineage sorting and lateral gene
transfer constitute major problems for inferring species trees from gene trees,
as they can sometimes lead to gene trees which conflict with the underlying
species tree. One particularly simple and efficient way to infer species trees
from gene trees under such conditions is to combine three-taxon analyses for
several genes using a majority vote approach. For incomplete lineage sorting
this method is known to be statistically consistent, however, in the case of
lateral gene transfer it is known that a zone of inconsistency does exist for a
specific four-taxon tree topology. In this paper we analyze all remaining
four-taxon topologies and show that no other inconsistencies exist.
