Lab 5 - Classification.docx - ANT 3514C Introduction to...

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ANT 3514C – Introduction to Biological Anthropology Lab 5: Classification Lab Objectives: Identify similarities and differences among a group of hypothetical organisms Construct a taxonomy for this group of organisms based on these traits Interpret the role of evolutionary process in constructing taxonomies Evaluate the traits for evolutionary significance Purpose: To understand the process of classifying organisms. Lab Activity: Classification of Caminalcules (adapted from Robert P. Gendron, Indiana University of Pennsylvania) Humans classify almost everything—including each other. This habit can be quite useful. For example, when talking about a car someone might describe it as a four-door sedan with a fuel injected V-8 engine. A knowledgeable listener who has not seen the car will still have a good idea of what it is like because of certain characteristics it shares with other familiar cars. Humans have been classifying plants and animals much longer than they have been classifying cars, but the principle is similar. One of the central problems in biology is the classification of organisms on the basis of shared character- istics, or traits . For example, biologists classify all organisms with a backbone as "vertebrates." In this case the backbone is a trait that defines the group. If in addition to a backbone an organism has gills and fins, then it is a fish, a subcategory of the vertebrates. This fish can be further assigned to smaller and smaller categories down to the level of the species. The classification of organisms in this way aids biologists by bringing order to what would otherwise be a bewildering diversity of species. (There are several million species, of which about 1 million have been named and classified.) The field devoted to the classification of organisms is called taxonomy [Gk. taxis , arrange, put in order + nomos , law]. Biologists use a taxonomic system that was devised by Carolus Linnaeus (1707-1778). It is a hierarchical system grouping organisms into ever more inclusive categories from species up to kingdom. Fig. 1 illustrates how four species are classified using this taxonomic system. (Note that it is standard practice to italicize the genus and species names.) KINGDOM Animalia Plantae PHYLUM Chordata Arthropoda Angiospermophyta CLASS Mammalia Insecta Monocotyledoneae ORDER Primates Carnivora Hymenoptera Liliales FAMILY Hominida e Canidae Apidae Liliaceae GENUS Homo Canis Apis Alium SPECIES sapiens lupus mellifera sativum Common Name “human” “wolf” “honeybee” “garlic” Figure 1 In the 18th C., many scientists believed that the Earth and all the organisms on it had been created suddenly in their present form as recently as 4004 BC. This popular view changed dramatically when Charles Darwin published On the Origin of Species in 1859. In his book, Darwin presented convincing evidence that life had evolved through the process of natural selection . The evidence gathered by 1
Darwin, and thousands of other biologists since then, indicates that all organisms are descended from a

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