The correct option is 2: Origin of metazoa. The Syncytial Theory, also known as the Ciliate Hypothesis, was proposed by Jovan Hadzi in 1953 and later championed by Hanson. This theory is a key hypothesis in evolutionary biology that directly addresses the grand challenge of explaining the evolutionary transition from unicellular Protists to multicellular animals, or Metazoa. Hadzi posited that the first multicellular animals arose not from a simple, spherical…Read More