What are three major trends of evolution in invertebrates?

Three major trends of evolution in invertebrates include the development of multicellularity, leading to more complex body structures and functions; the evolution of symmetry, particularly bilateral symmetry, which allows for more efficient movement and organization of body systems; and the emergence of specialized body systems, such as circulatory and nervous systems, which enhance survival and adaptability in various environments. These trends have contributed to the incredible diversity and ecological success of invertebrate species.