1.1 Identifying, Naming and Classifying Species SBI3U

Introduction to Classification Find a group of 3. All individuals must bring their school bags to the front of the room. In your groups, determine different ways in which you can categorise the numerous school bags. (look for similarities) Record your classification on the hierarchy given by the instructor

Remember… A species is a group of related organisms. Why can’t scientists just call them both bears? What problems are solved by determining that these two organisms are different species?

Why can’t scientists just call them both trees?

How could scientists determine if the green iguana is a different species from others in the island?

Idenfying and naming new species Sientists rely on various methods to compare, define and classify species. Scientists have not been able to come up with one definition of a species. As a result, they now use a variety of « Species Concepts » to describe different species.

Concept 1:Morpholocial Species Focused on the morphology (appearance) of the organism Scientists compare measurements and descriptions of similar organisms. Disadvantage: it is difficult to determine how many differences are required to consider organisms to be separate species. Also appearances can be deceiving

Concept 2: Biological Species Concept Looks at similar characteristics Looks at organisms ability to interbreed and produce viable offspring. Disadvantage: This cannot be applied to populations that are separated, that reproduce asexually or for fossils.

Concept 3: Phylogenetic Species Looks at the relationships between animals and their common ancestor. Through DNA analysis, scientists are able to compare organisms and look at their evolutionary relationships. Disadvantage: Evolutionary history is not known for all species.

Which species concept would you use to identiy each of the following? Chicken and Duck Two similar types of lizards A female horse and a male donkey reproduce to create a mule. The mule is a sterile organism Two distinct species of lizards had a common ancestor

Naming Species Taxonomy: branch of biology that identifies names and classifies species based on natural features. Carolus Linnaeus is the father of Taxonomy, and he created Binomial Nomenclature; a system designed to give organisms a two part name (species name) Why would Linnaeus want to create a classification system that was known/used worldwide?

Binomial Nomenclature Binomial nomenclature refers to a two-part naming system. An organism’s scientific or species name has two parts. First part, genus name, identifies the group of closely related species to which the species belongs. The second part of the name identifies the species. Both are either italicized or underlined. Homo sapiens Genus species First letter is capitalized First letter is lower case

Classification of species This system was also developed by Linnaeus Classification: the grouping of organisms based on a set of criteria that helps to organize and to indicate evolutionary relationships. All species are organized in a hierarchical manner, from most general to most specific.

How many ranks can you count? Which rank is the most general? Which rank is the most specific? What similarity is shared by the organisms in the top rank?

Hierarchical Classification There are 8 categories in which the animals must be classified. Each category is known as « rank » and named group of species is known as « taxon »

Rank Taxon Increasing Similarity Increasing Diversity

Hierarchical Classfication King Philip Cannot Operate Frog Guts Successfully RANKS Increasing Similarity

What is the taxonomic classification of the wolf?