Answer:
Explanation:
Embryos of different vertebrate groups are morphologically similar during the early stages of development. Such similarity suggests a common ancestry. The closer the resemblance between the early stages of different organisms the closer their evolutionary relationship.
Homologous structures are structures that are superficially different and serve quite different functions but have a similar internal structure. Organisms sharing homologous structures are believed to have a common ancestral origin.
Antigen-antibody reactions, rhesus factor, blood groups and haemoglobin structure reveals some phylogenetic relationship among organisms suggesting common ancestry.
