The species represents one certain type of organism, which, by definition, cannot interbreed with an organism of a different species. The largest or most general grouping is at the kingdom level, which Aristotle originally used to separate plants (plant kingdom) and animals (animal kingdom). Interestingly, Aristotle also identified a third kingdom—the mineral kingdom—in which hydrocarbon traps presumably belong. | The species represents one certain type of organism, which, by definition, cannot interbreed with an organism of a different species. The largest or most general grouping is at the kingdom level, which Aristotle originally used to separate plants (plant kingdom) and animals (animal kingdom). Interestingly, Aristotle also identified a third kingdom—the mineral kingdom—in which hydrocarbon traps presumably belong. |