Any taxonomic scheme has problems. We tend to label and dismiss anything once we assign it a category. Our classifications blind us to the wildness of natrual organization by supplying coneptual boxes to fit our preconceived ideas. They should reflect our study of nature. The two-tiered five-kingdom system will always need revision. Whatever its difficulties, it does not perpetuate the age-old errors of the “animal versus vegetable” dicholomy. We can group life into three or five or a million categories, but life itself will elude us.
Lynn Margulis, Symbiotic Planet: A New Look at Evolution, 1998, p. 68.
