*Turn in Catalyst Sheet & Unit 5 Packet* Friday May 12, 2017 I can: use modern classification systems to infer evolutionary relationships Agenda (10) Catalyst (10) Classification Inquiry (15) GN: Classification (35) Cladogram Lab (10) IP: Classification (5) Exit Ticket Catalyst Give an example of a virus. Can antibiotics be used to treat viral infections? You get a disease and your body recognizes the virus the next time you are infected. What kind of immunity is this? You are immune from a disease b/c you were breastfed. What kind of immunity do you have? *Turn in Catalyst Sheet & Unit 5 Packet* HW: None

Categorizing Organisms Part 1: Discuss with your group how you could group the organisms on your desk into 3 groups. Group 1 Organisms Characteristics Group 2 Group 3

Categorizing Organisms Part 2: Now discuss with your group how you would organize these organisms according to when in time they evolved.

Because of evolution there is great diversity of life!

Scientists need to organize over 2 million organisms!

Scientists need to organize over 2 million organisms!

Classification Classification: grouping organisms based on common ancestors and characteristics.

History of Classification

1. Aristotle classified organisms as either plants (plantae) or animals (animalia) But is everything a plant or an animal?

2. Carolus Linneaus developed the hierarchical system, which classifies in levels based on physical similarities

most general King Phillip came over for good most specific spaghetti

Write on your board: Which is the level more specific than genus?

Write on your board: Which is the next level that is more general than family?

Write on your board: Which levels are more specific than order?

Write on your board: Which is the most general level?

Write on your board: Which levels are more specific than family?

Genus: Species: Homo sapiens Genus species Most specific level Carolus Linneas also developed the system of binomial nomenclature = naming organisms with two names. The scientific name of an organism always consists of its genus name and its species name. Genus: Second most specific level Most specific level Species: Homo sapiens Genus species

What genus does this organism belong to? What species? Canis familiaris dog

What genus does this organism belong to? What species? Felis domesticus cat

Problems with Classification What kinds of problems could scientists run into if they were just grouping organisms by similar physical characteristics?

Problems with Classification What kinds of problems could scientists run into if they were just grouping organisms by similar physical characteristics? Turn and Talk

Modern Classification Biologists now group organisms according to their evolutionary relationships

Scientists use the following criteria to classify organisms: Structural similarities: similar fossils or anatomy Biochemical analysis: DNA, proteins and amino acids (still the best) Embryology: similar embryos

What type of evidence? comparing unborn fetuses of whales and sharks

What type of evidence? comparing DNA of whales and sharks

What type of evidence? comparing the fins of whales and sharks

Phylogenetic trees (aka cladogram)

Phylogenic trees show when in time traits developed You can use them to: 1. Find which organisms are most primitive. 2. Find which organisms are most closely related

Phylogenic trees show when in time traits developed You can use them to: 1. Find which organisms are most primitive. 2. Find which organisms are most closely related

Primitive: Primitive = old, simple The most primitive species are at the bottom (left) The most recent species are at the top (right)

Most primitive Most recent

Common Ancestry Each branch point represents the common ancestor of two species.

Organisms have the traits that come before them ex. everything after the Perch has lungs ex. What characteristic does the salamander have that the perch lacks? Species are closely related if they branch off close together

Think: In the cladogram, what species is most primitive? In the cladogram, what species is least primitive? What traits does the lizard have? What traits does the salamander have? What is the chimp most closely related to? Is the lizard more closely related to the salamander or the perch?

How to Make a Cladagram Found on Earth? Alive? Mammal? Walks? Human Lizard Rock Whale

Candy Cladogram Stay with your table ONLY Check your answers with me BEFORE you eat any candy Save bags – do not throw out! Paper due at end of class Work on Phylogenetic Trees Classwork & Exit Ticket when complete