The current scientific definition is in no way rigorous enough to satisfy a scientist.This definition would allow slime molds (motile fungi) and Venus flytraps (a plant that 'moves' and 'eats other organisms') to be 'animals.' I would simply write: 'animal: a monophyletic kingdom of multicellular heterotrophic eukaryote with internal digestion. That is, animals are all descended from a common ancestor. They are organisms composed of many individual cells with distinct nuclei and membrane-bound organelles. They obtain nutrition solely by ingesting organic matter and then breaking it down.'
Movement is no kind of animal criterion. When was the last time a coral or barnacle moved? If you want to say that movement only has to apply to parts of the organism, then the Venus flytrap certainly moves, and even a tree moves when the wind blows. Dhicks3 17:30, 12 November 2010 (UTC)
U.S./American usage of 'animal' meaning 4 legged fauna. i.e. phrases like "birds, fish, and animals"??
"Evolutionary biologists say humans are also animals."
Just evolutionary biologists? I was under the impression that under this scientific definition, every living thing was either a plant or an animal. We are not plants. We eat things, we have cells, and there is no biological difference between us and "other" animals. Under this BIOLOGICAL definition, I don't think there's any question of whether we are animals. (We're not plants, or silicon based, etc)
num. 2 already covers non-scientific usage, IE all living things which aren't plants, except humans.
EDIT: I just changed the sentence to something more accurate:
"Humans are also animals, under the scientific definition, as we are not plants."
This fits with the previous sentence as well. I'll keep this as an explaination. 22.214.171.124 23:05, 11 May 2008 (UTC)
I think this is a specific expression, from Aristotle I think, not a general use of the word "animal." Redddogg 03:55, 27 June 2010 (UTC)