Applied to humans, a Linnaean chart could be filled out in the following way. (Notice the prevalence of Greek and Latin terminology.)
Domain: Eukaryota – containing all organisms which have cells with a nucleus.
Kingdom: Animalia – including organisms with eukaryotic cells that have a cell membrane but lack a cell wall, are multicellular, and heterotrophic (meaning that they cannot synthesize their own food, as plants do.)
Phylum: Chordata – including animals with a notochord, dorsal nerve cord, and pharyngeal gill slits.
Subphylum: Vertebrata – animals possessing a backbone, which may be made of cartilage, to protect the dorsal nerve cord.
Class: Mammalia – endothermic vertebrates with hair and mammary glands which, in females, secrete milk to nourish the young.
Subclass: Placentalia – including animals that give birth to live young after a full, internal gestation period.
Order: Primates – including animals with a collar bone, eyes that face forward, grasping hands with fingers, and two types of teeth: incisors and molars.
Family: Hominidae – including primates with upright posture, a large brain, stereoscopic vision, a flat face, and hands and feet with different specializations (such as grasping and walking).
Genus: Homo – having an s-curved spine, “man.”
Species: Homo sapiens – characterized by a high forehead, well-developed chin, and thin skull bones.
While Latin and Greek are no longer used when scientists write or e-mail each other, these languages continue to survive in the names given to plants and animals. For those few among us who did study Latin and Greek, here is one practical application of hours and hours of learning vocabulary and conjugating verbs: it allows one to more easily see the origins of the terms used and thus facilitates our understanding of what is meant.
For all those others who did not study these ancient languages, consider the old saying “The more it changes…”