Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity, and other resources. The term anthropogenic designates an effect or object resulting from human activity.
Animals can be divided broadly into vertebrates and invertebrates. Vertebrates have a backbone or spine (vertebral column), and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals. The remaining animals are the invertebrates, which lack a backbone. These include molluscs (clams, oysters, octopuses, squid, snails); arthropods (millipedes, centipedes, insects, spiders, scorpions, crabs, lobsters, shrimp); annelids (earthworms, leeches), cnidarians (jellyfish, sea anemones, corals), and sponges.
Invertebrates are all animals without a backbone. Invertebrates never develop a backbone or spine. This is in contrast to the subphylum Vertebrata, in which these species do have a backbone. Many animals are invertebrates including insects, worms, crabs, mollusks, cuttlefish, spiders, starfish, squid, and so forth. The majority of species on our planet are actually invertebrates.