Classification of Life Sec. 2C

Objectives I will be able to explain the reasons for classifying living organisms. I will be able to list in order the 7 levels of the modern classification system. I will be able to describe two major problems associated with the modern classification system. I will be able to refute the supposed evolutionary significance of the modern classification system.

Why Classify? By learning characteristics about individuals, you can also learn characteristics about the whole group. Generalization Classification makes finding information about specific organisms easier.

to arrange things into groups Classify to arrange things into groups Classification: the process of grouping things based on their similarities

the science of classifying organisms into groups Taxonomy (from Gk. taxis – arrangement, order) the science of classifying organisms into groups

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.

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 .

Animals FISH – swim BIRDS - fly LAND ANIMALS - walk 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 Swedish-naturalist, discovered problems in the systematic arrangement for botany and began to sketch his own classification method.

Species Plantarum Systema Naturae 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 1758 forms the basis for animal 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.

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

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..

Problems of Classification Uncertainties in classifying Same species? False conclusions Evolutionary approach Common ancestors? Nonbiblical worldviews Species and biblical kinds