Most animals come from or branched from bilateral organisms. Flatworms, chordates, fishes, ichthyostegans, amphibians, lizards, early shrew-like mammals, spider monkeys, gorillas, humans. The other main symmetry is radial, like starfishes. I'm not an expert, but I saw it on youtube hehe.
Jance_Nemin t1_iu7ch7p wrote
Reply to ELI5 why do humans and most (all?) animals have symmetrical bodies? by kisamoto
Most animals come from or branched from bilateral organisms. Flatworms, chordates, fishes, ichthyostegans, amphibians, lizards, early shrew-like mammals, spider monkeys, gorillas, humans. The other main symmetry is radial, like starfishes. I'm not an expert, but I saw it on youtube hehe.