Similarities in structure among distantly related species are analogous if they evolved independently in similar environments. They provide good evidence for natural selection. Examples of evidence from embryology which supports common ancestry include the tail and gill slits present in all early vertebrate embryos
Strong hydrologic connections among terrestrial and inland aquatic realms exist in both river floodplains and dryland ecosystems. In the evolution of river floodplains terrestrial vegetation diversifies inland aquatic habitats, providing a range of colonization options for different organisms
