Unit 1 Lesson 2 Classifying Organisms • What methods are used to classify living things into groups? • Why does every species have a scientific name? Classify to arrange things into groups Classification: the process of grouping things based on their similarities Taxonomy (from Gk. taxis – arrangement, order) the science of classifying organisms into groups Two types of objects Inanimate: “not living” Animate: “possessing life” Classifying Living Things • There have been many different ideas about how to organize, or classify, living things. • Aristole classified organisms into two main groups: plants & animals • Carolus Linnaeus classified organisms into two main groups, called kingdoms, based on similar structures. What evidence is used to classify living things into groups? · Cell type, complex or simple · Their ability to make food · The number of cells in their body Classifying Living Things • The current classification method for organisms is called systematics. • Systematics uses all known evidence to classify organisms, including cell type, how food and energy are obtained, structure and function of features, common ancestry, and molecular analysis. The Classification Hierarchy First recorded classification of organisms was attempted by Aristotle the Greek scientist and philosopher. Aristotle’s Classification System Plants HERBS - if they lacked woody parts SHRUBS - if they had several short woody stems TREES - one large woody stem . Aristotle’s Classification System Animals FISH – swim BIRDS - fly LAND ANIMALS - walk artificial classification system based on appearance (physical characteristics) Aristotle's system was used for approximately 2,000 years. (used into the 1600’s) Carolus Linnaeus In the 1700's Carolus Linnaeus, a Swedishnaturalist, discovered problems in the systematic arrangement for botany and began to sketch his own classification method. Carolus Linnaeus set forth a new classification system in his works (books he wrote). • Species Plantarum • Systema Naturae Species Plantarum • published 1753 • forms the basis for plant classification Systema Naturae • published 1753 • forms the basis for plant classification Carolus Linnaeus Linnaeus is known as the father of modern biological classification or the father of taxonomy. Carolus Linnaeus Linnaeus also established the modern scientific method of naming plants and animals. His system is also an artificial classification system (based on physical characteristics). It has more flexibility than the previous systems. It is still used today. Linnaeus's 7 Basic Levels of Classification His system has 7 basic levels (largest --->smallest) kingdom phylum (division) class order family genus species Species are often divided into sub-species (or varieties – like dogs). Subphyla & subclasses may also be used. kingdom Science Use a classification category that ranks above phylum and below domain Common Use a territory ruled by a king or a queen The more classification levels that two organisms share, the more characteristics they have in common. As you move down the levels there are fewer kinds of organisms in each group. Organisms are placed into domains and kingdoms based on their cell type, their ability to make food, and the number of cells in their bodies. Levels of Classification Some classification systems have an eighth level – domain – that is a level higher than kingdom. Levels of Classification Organisms are now classified into one of three domains and then into one of six kingdoms. Unicellular prokaryotes The "true bacteria". Examples: Enteric bacteria like E. coli, Salmonella typhus, Legionella, Heliobacter pylorii (cause of many ulcers), Neisseria gonorrhea (cause of gonorrhea), Nitrogen-fixing bacteria that are able to convert nitrogen gas into ammonia. Clostridium (tetanus, botulism). also unicellular prokaryotes but they are found in some of the most extreme environments on Earth (such as hot springs, very salty water, swamps, volcano vents in the Pacific Ocean floor, and the intestines of cows) Protist Fungi Animal Plant The Six Kingdoms Kingdom Archaebacteria Kingdom Eubacteria Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia Kingdom Archaebacteria In 1983, scientists tool samples from a spot deep in the Pacific Ocean where hot gases and molten rock boiled into the ocean form the Earth’s interior. To their surprise they discovered unicellular (one cell) organisms in the samples. These organisms are today classified in the kingdom, Archaebacteria. Archaebacteria are found in extreme environments such as hot boiling water and thermal vents under conditions with no oxygen or highly acid environments. Kingdom Eubacteria Like archaebacteria, eubacteria are complex and single celled. Most bacteria are in the EUBACTERIA kingdom. They are the kinds found everywhere and are the ones people are most familiar with. Eubacteria are classified in their own kingdom because their chemical makeup is different. Most eubacteria are helpful. Some produce vitamins and foods like yogurt. However, some eubacteria, Streptococci, can give you strep throat! Kingdom Protista Slime molds and algae are protists. Sometimes they are called the odds and ends kingdom because its members are so different from one another. Protists include all microscopic organisms that are not bacteria, not animals, not plants and not fungi. Most protists are unicellular. You may be wondering why those protists are not classified in the Archaebacteria or Eubacteria kingdoms. It is because, unlike bacteria, protists are complex cells. Kingdom Fungi Fungi are organisms that biologists once confused with plants, however, unlike plants, fungi cannot make their own food. Most obtain their food from parts of plants that are decaying in the soil. Mushrooms, mold and mildew are all examples of organisms in the kingdom fungi. Most fungi are multicellular and consists of many complex cells. Kingdom Plantae With over 250,000 species, the plant kingdom is the second largest kingdom. Plant species range from the tiny green mosses to giant trees. Plants are autotrophs, organisms that make their own food. You are probably quite familiar with the members of this kingdom as it contains all the plants that you have come to know - flowering plants, mosses, and ferns. Plants are all multicellular and consist of complex cells. Kingdom Animalia All animals consist of many complex cells. They are also heterotrophs. Members of the animal kingdom are found in the most diverse environments in the world The animal kingdom is the largest kingdom with over 1 million known species. What about Humans? Man is not an animal; he is God’s highest creation and created in God’s image. Christian Classification System? Why don’t Christians invent a “Christian Classification System” that would not be influenced by evolutionary bias? Any new system that uses physical characteristics as the basis for classification would likely group organisms quite similarly to the current system. Christian Classification System? There is a Christian classification system that has been proposed called baraminology. The term baraminology comes from the Hebrew words bara, meaning “create,” and min, meaning “kind.” Baraminology attempts to classify organisms according to their biblical kind. Christian Classification System? Since one of the primary functions of a classification system is to eliminate confusion regarding organisms, having a separate system that is similar but not really parallel would likely add confusion rather than eliminate it. A more reasonable solution is for Christians to accept the Bible as the source of all truth and reject any evolutionary bias found in the current system..