11.Homologous structures are those structures which are derived from the common ancestor. These structures are similar in other species e.g. the wings of a bird and the forelimbs of bat are homologous structures. Therefore, it clearly indicates that these species have evolved from a common ancestor. Solution 11.Homologous structures are those structures which are derived from the common ancestor. These structures are similar in other species e.g. the wings of a bird and the forelimbs of bat are homologous structures. Therefore, it clearly indicates that these species have evolved from a common ancestor..