Previous chapters have dealt basically with how the organisms function mostly at the molecular ievel. We now explore organism-level stmcture-and. therefore, function-and on a grander tale. the biology of the organism and how organisms as populations interact with one another pd with other organisms. as well as with their environment. Carolus Linnaeus is credited with org-sizing Irvinp things into understandable groups based on their structures and giving them a pro-part name. Today. we use many characteristics, including behavior and, more recently, DNA pnlysis. Since the ariiest times. humans have attempted to understand their world, and one of are ways to start the process is to organize it, The way humans have done this has changed over time. This chapter is about the grouping of organisms. Some of the vocabulary at the end of the charter will not be detailed here, but we suggest that the student know all of those terms; this holdstrueforall thechapters in this book.
Taxonomy. or the science of classifying organisms, groups organisms into categories based on «atrium characteristics.
Just as we find in grocery stores. the organisms are placed in specific categories. Imagine trying to find an item in the store if all of the delivery vehicles dumped their goods at the front door. In a like manner. grouping organisms has many benefits. Imagine proposing that a predator of a parasite be introduced into the local environment in an attempt to control the parasite population, but instead. the organism you believe to be the predator is actually a slight variation of that predator and has no interest whatsoever in the parasite you are trying to eliminate. You may now have two problems to deal with. and at the very least, you haven’t done anything to help control the parasite,
Aristotle's classification system proposed that if something moves. it is an animal, and if it doesn‘t. it is a plant. 0! course. sponges were mistakenly taken for plants, and when they threatened the shellfish industry centuries ago, were "killed" by being cut up and tossed back into the tea. To the surprise of the shellfish harvesters. the next year. the number of sponges had increased; the shell fishers were actually helping the sponges reproduce (asexually) by their actions.
Linnaeus proposed naming organisms by a two-name system that we call binomial nomenclature. There were very specific names based on the organism’s characteristics and are the genus and species of today. Note that the genus is always capitalized and the species is not, as in Terrestris «mericanut. and the entire name is underlined or italicized.
The modern system of classification now contains five major groups called kingdoms. Life on the planet could be seen as analogous to a grocery store. The major consumer item areas. such as produce. dairy, and canned goods, would be analogous to the kingdoms of living things. As with the grocery store. the tub-categories get more and more specific until it is possible to name an item exclusive of all other items in the store. You should know the categories. starting with the largest (the kingdom) and continuing to narrower and narrower groups in the sequence: Kingdom. Phylum. Class, Order. Family. Genus. and Species. in plants, the word “phylum" is replaced with