How does a fish and human embryo look identical in the early stages of embryonic development?

In the early stages of embryonic development, fish and human embryos exhibit similar structures, particularly in the formation of pharyngeal arches, which resemble gill structures in fish. Both embryos share a common vertebrate ancestry, leading to the presence of analogous features such as a notochord, neural tube, and limb buds. These similarities reflect the conserved patterns of development across vertebrates, highlighting the fundamental biological processes that govern early embryogenesis.