In the discipline known as taxonomy, scientists classify organisms and assign each organism a universally accepted name. The first part of the scientific name—in this case,Ursus—is the genus to which the organism belongs. Agenus(JEE-nus; plural: genera, JEN-ur-uh) is a group of closely related species. Linnaeus's hierarchical system of classification includes seven levels. They are—from smallest to largest—species, genus, family, order, class, phylum, and kingdom Family- group of genera that share many characteristics Order- group of similar families Class- group of similar orders Several different classes make up a phylum The kingdom is the largest and most inclusive of Linnaeus's taxonomic categories. Linnaeus named two kingdoms, Animalia and Plantae Carolus Linnaeus, a Swedish botanist who lived during the eighteenth century. He developed a two-word naming system called binomial nomenclature (by-NOH-mee-ul NOH-mun-klay-chur). This system is still in use today. In binomial nomenclature, each species is assigned a two-part scientific name. As biologists classify the diversity of life, what two main tasks do they carry out? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner.
Section 2: Darwin's ideas about descent with modification have given rise to the study of phylogeny, or evolutionary relationships among organisms The strategy of grouping organisms together based on their evolutionary history is called evolutionary classification. Species within a genus are more closely related to each another than to species in another genus. According to evolutionary classification, that is because all members of a genus share a recent common ancestor Characteristics that appear in recent parts of a lineage but not in its older members are called derived characters. Derived characters can be used to