C LASSIFICATION Why do you think scientists like to put organisms into groups, like mammals or insects?

W HAT IS C LASSIFICATION ? Classification is the arrangement of organisms into orderly groups based on their similarities Classification is also known as taxonomy Taxonomists are scientists that identify & name organisms Taxonomists classify organisms into groups called taxon

W HY C LASSIFY ? Scientists have classified about 2 million species However, there are many more organisms than we have found. Estimates usually range from 3-10 million, but go as high as 50 million That shows Earth has a tremendous amount of biodiversity (variety of organisms) This is only 1-5% of all organisms that have ever lived!!!!!

Sea “horse”?? W HY C LASSIFY ? Accurately & uniformly names organisms Prevents misnomers such as starfish & jellyfish that aren't really fish Uses same language (Latin or some Greek) for all names

C ONFUSION IN U SING D IFFERENT L ANGUAGES FOR N AMES

L ATIN N AMES ARE U NDERSTOOD BY ALL T AXONOMISTS

E ARLY T AXONOMISTS 2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into plants & animals He subdivided them by their habitat --- land, sea, or air dwellers

C AROLUS L INNAEUS : 1707 – th century taxonomist Classified organisms by their structure Developed naming system still used today

C AROLUS L INNAEUS Called the “Father of Taxonomy” Developed the modern system of naming known as binomial nomenclature Two-word naming system

B INOMIAL NOMENCLATURE Genus species Latin or Greek Capitalize genus, but NOT species Underline when writing Italicized in print American Robin

B INOMIAL NOMENCLATURE The International Code for Binomial Nomenclature contains the rules for naming organisms All names must be approved by International Naming Congresses (International Zoological Congress) This prevents duplicated names Organisms are often named using descriptive words, like habitat or a physical characteristic OR sometimes using the person whom discovered them

L EVELS OF C LASSIFICATION The levels of classification are a hierarchy of groups (taxa) from broadest (domain) to most specific (species)

L EVELS OF C LASSIFICATION Domain Kingdom Phylum Class Order Family Genus Species Sometimes subspecies is added to the bottom of the list Subspecies are the same species, but they live in different areas

King Phillip Came Over For Good Soup!

S YSTEMATICS Systematics is a science whose goal is to classify organisms in terms of their natural relationships Phylogenetics is a type of systematics

P HYLOGENETICS The analysis of the evolutionary or ancestral relationships among taxa. Classification is based on evolutionary relationships Found by studying RNA, DNA, amino acids, homologous structures, and embryos These relationships are often shown in a cladogram

C LADISTICS Cladisticsis a type of phylogenetics A cladogram is a type of phylogenetic diagram

C LADISTICS Cladogram -A diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales Shared characters are features that ALL members of a group have in common. For example, all organisms in the Domain Eukarya domain have true nuclei Derived characters are features that evolved only in the group under consideration. Feathers for example, are believed to have evolved only in the birds, not from a common ancestor that they have with reptiles.

C LADISTICS Cladograms are organized into clades, which is an ancestor and all of its descendants. Cladograms are not only based on physical features, they are also based on biomolecular similarities (like DNA, chromosomes and proteins) Outgroups -have no shared characteristics with the other organisms in the diagram and are only distantly related

C LADOGRAM Feathers are a derived characteristic in the birds Hagfish are the outgroup Jaws are a shared characteristic between all organisms except the hagfish

C LADOGRAM Hair is a derived characteristic in leopards (on this cladogram, only leopards have hair) NOTE-hair is a shared characteristic in the previous cladogram, so these characteristics can change based on the cladogram Character tables may help you make cladograms

D ICHOTOMOUS K EYS Used to identify organisms "Dichotomous" means "divided into two parts". Characteristics given in pairs Read both characteristics and either go to another set of characteristics OR identify the organism

D ICHOTOMOUS K EYS Always read both choices, even if the first seems to be the logical one at first. Be sure you understand the meaning of the terms involved. Do Not Guess. When measurements are given, use a calibrated scale. Do Not Guess. Since living things are always somewhat variable, do not base your conclusion on a single observation. Study several specimens to be sure your specimen is typical. If the choice is not clear, for whatever reason, try both divisions. If you end up with two possible answers, read descriptions of the two choices to help you decide

D ICHOTOMOUS K EYS 1. a. Bean round………..Garbanzo bean b. Bean elliptical or oblong…..Go to 2 2. a. Bean white…………White northern b. Bean has dark pigments……Go to 3 3. a. Bean solid in color…….Go to 4 b. Bean is spotted……..….Pinto bean 4. a. Bean black………… Black bean b. Bean reddish-brown…….Kidney bean

M AKING D ICHOTOMOUS K EYS Eliminate an organism in every step (one part leads to a name, the other part leads to another step) Use measurements rather than terms like "large" and "small". Try to make the choice a positive one -something "is" instead of "is not".

M AKING D ICHOTOMOUS K EYS - C ONTINUED If possible, start both choices of a pair with the same word. If possible, start different pairs of choices with different words. Precede the descriptive terms with the name of the part to which they apply.(like legs are red instead of red legs)

DICHOTOMOUS KEY ASSIGNMENT You will be creating your own dichotomous key The subjects of the key will be all the people in your row of desks Criteria must be high school appropriate and non-insulting Everyone should have between 7 – 10 people