Unit 1: Diversity 1.1-Identifying, Naming and Classifying Species SBU3U1

Overview:SPECIES SPECIES- a group of organisms that can interbreed in nature and produce fertile offspring. -Scientists have identified approx. 2 million different species on earth to date. -However they estimate that the total number on Earth actually ranges from 5- 20 million.

Identifying and Naming Species Scientists have used different methods to classify a species which are called species concepts: 1)Morphological species concept 2)Biological species concept 3)Phylogenetic species concept

1)Morphological Species Concept Morphology focuses on body shape, size, and colour Scientists compare measurements and descriptions of similar organisms over time

1)Morphological Species Concept Advantage: it is simple and widely used, especially for plants Disadvantage: difficult to determine how much variation is too much because majority of populations have non-identical individuals

2)Biological Species Concept Biological = whether or not 2 organisms can produce fertile offspring Therefore, if 2 individuals can mate under natural circumstances to produce offspring that can live and reproduce they are the same species

2)Biological Species Concept Advantage: widely used by scientists Disadvantage: This cannot be applied to populations that are separated, that reproduce asexually or fossils.

3)Phylogenetic Species Concept Phylogenetic focuses on evolutionary history among organisms Species are a cluster of organisms distinct from other clusters Pattern of relationship among organisms DNA analysis can be used

3)Phylogenetic Species Concept Advantages: applies to extinct species and uses DNA analysis Disadvantage: not all evolutionary histories are known

Naming Species Carolus Linnaeus ( Carl von Linne) = = the Father of taxonomy Taxonomy: identifies, names, and classifies species based on natural features Developed the System of binomial nomenclature two parts naming system

Scientific Naming System Each species has a 2 part latin name Homo sapiens (Humans) “genus name “ “species name” First part of name is called genus (capitalized + italicized) Second part of name is the specific species (lower case + italicized)

Check your understanding… 1.Which of the following is the scientific name for a cat ? Felis Catus Felis catus felis catus

Check your understanding… 2. The offspring of a male lion + female tiger is a liger. Ligers are infertile. Does this mean that lion and tigers are the same species? Explain.

Hierarchical Classification Classification is the grouping of organisms based on a set of criteria that helps to organize and indicate evolutionary relationships. ( developed by Linnaeus) Hierarchal Classification= arrangement of species into categories from most general to most specific

A hierarchy arranges items above, below, or at the same level as other items in the group. Hierarchal classification is considered to be a “nested classification”

Taxonomic Categories Used To Classify Organisms UNIT 1 Chapter 1: Classifying Life’s Diversity Section 1.1 Taxonomic Categories Used To Classify Organisms Taxonomic categories are used to classify organisms that have been identified. The categories or groupings are arranged in a hierarchy. Each level or category is known as the rank. The particular classification of an organism at each rank level is called the taxon (pl. taxa).

Taxonomy Cont’d… There are 8 taxonomic ranks. Domain is the most general, containing the most species. The species rank is specific to one species. It goes like this… D- domain ( most general) K – kingdom P – phylum C – class O- order F – family G - genus S – species (Most specific)

EXAMPLE: GREY WOLF

Classification of Living Things Video https://www.youtube.com/watch?v=vqxomJIBGcY

HOMEWORK -Read and make notes 1.1-pg. 10-15 -Summarize & Copy Table 1.1 ( pg. 11) in your notebook -Complete pg. 13 #1-4, pg. 16 # 6-11