UNIT 6 - Evolution SWBAT compare the relatedness of various species by applying taxonomic principles (cladistics, phylogeny, morphology and DNA analysis)

Classification in Everyday Life Think about classification that is used in everyday life. Can you give an example?

What is Classification? Classification is the grouping of information or objects based on similarities Taxonomy is the science of grouping and naming organisms

How Many Species Are There? About 1.8 million species have been given scientific names - nearly 2/3 of these are insects Total number of living species is estimated to be between 13 and 14 million, with most being insects and microscopic life forms in tropical regions However, we may never know how many there really are because many of them will become extinct before being counted and described

Why should we be worried to lose many animals every week to extinction?

Classification Game In the following few slide, you will find 14 different organisms, each of them labeled with a letter. In the following few slide, you will find 14 different organisms, each of them labeled with a letter. With your partner, write down two main classification types (example red/green). With your partner, write down two main classification types (example red/green). Then place the corresponding letters under the correct classification. Then place the corresponding letters under the correct classification. After making the two main categories, try to narrow each of those down into sub- categories After making the two main categories, try to narrow each of those down into sub- categories

Any Problems?

Possible Solutions Plants Animals ????

Any Problems? There were actually several different ways to go about classifying these 14 organisms. There were actually several different ways to go about classifying these 14 organisms. You might have done color, shape, size, number of legs… the possibilities are endless. You might have done color, shape, size, number of legs… the possibilities are endless. You might have encountered one or two that really did not fit into either of your two classifications, what should you do when this happens? You might have encountered one or two that really did not fit into either of your two classifications, what should you do when this happens? Make a new classification of course! And this is what scientist have done as well through the years. Make a new classification of course! And this is what scientist have done as well through the years.

Why classifying organisms? THINK BOX

Why Classifying Organisms? To represent relationships among organisms To makes things easier to find, identify, and study To understand our own evolution!

Devil Cat Reference: © TeacherWeb, Inc..

Ghost Cat Reference: © TeacherWeb, Inc.

Mountain Lion Reference: © TeacherWeb, Inc.

Screaming Cat Reference: © TeacherWeb, Inc.

Puma Reference: © TeacherWeb, Inc.

Florida Panther Reference: © TeacherWeb, Inc.

Cougar Reference: © TeacherWeb, Inc.

There are at least 50 common names for the animal shown on the previous 7 slides. Common names vary according to region.

Levels of Classification 7 levels known as taxa (sing. taxon) 1. Kingdom 2. Phylum 3. Class 4. Order 5. Family 6. Genus 7. Species King Philip Can Order For German Students

A Closer Look at the Taxa As one goes from the Kingdom to the Species (DOWNWARD)…An increase in the similarity between organisms occur There are fewer numbers of different kinds of organisms

Categories Within Kingdoms Kingdoms are divided into groups called phyla Phyla are subdivided into classes Classes are subdivided into orders Orders are subdivided into families Families are divided into genera Genera contain closely related species Species is unique

Human Classification Kingdom : Animalia (animal in Latin) Phylum : Chordata (spinal cord) Class : Mammalia (mammary glands) Order : Primates (two mammary glands) Family : Hominidae (bipedalism) Genus : Homo Species : sapiens

IBE – JTPS (Justify – Think Pair Share) Interpret this diagram

J-TPS (Justify –Think Pair Share) THINKPAIR SHARE - observe it - describe it - interpret it (what can you infer about that diagram?)

Cladistics –classification based on common ancestry –a cladogram is a tree that indicates how species are related What is a species?

group of species that share a common ancestor. Derived character Node Each place where a branch splits Derived traits are traits that are shared by some species but are not present in others. Clade What do the words “ancestor” and “descendant” mean? Cladogram

Derived characters –more closely related species share more derived characters When a DERIVED CHARACTER is above an organism, the organism lacks that derived character

Derived characters –more closely related species share more derived characters When a DERIVED CHARACTER is below an organism, the organism possess that derived character

Molecular evidence reveals species’ relatedness New technology allow biologists to compare groups of species at the molecular level DNA Protein Biochemistry (chemical processes related to biology)

Like family trees, phylogenetic trees represent patterns of ancestry. However, while families have the opportunity to record their own history as it happens, evolutionary lineages do not— species in nature do not come with pieces of paper showing their family histories. Instead, biologists must reconstruct those histories by collecting and analyzing evidence, which they use to form a hypothesis about how the organisms are related—a phylogeny. Check your understanding

The more related organisms are 1. the more characters they share 2. the more evolved they are 3. the stronger are 4. all of above Check your understanding

A clade is 1. a group of species coming from the same ancestor 2. a group of organisms belonging to the same species 3. a group of organisms able to reproduce and give fertile offspring 4. all of above Check your understanding

Cladistics is 1. the classification of organisms based on common ancestors 2. the classification of organisms based on physical characteristics 3. the classification of organisms based on their behaviours 4. all of above Check your understanding

List the derived characters present in this cladogram: _________________________________________________ _________________________________________________ ________________________________________

Check your understanding Where is the ancestor of A, B and C?

According to this phylogenetic tree, which organism is most closely related to R?

Revisit IBE – Interpret this diagram

Revisit IBE- interpreting cladograms Do you see ancestor/s and descendants? Do you see derived characters? Which one/s? What are the red marks called? Which are the species more closely related? Do you see any evolutionary relationship among these organisms?

J-TPS (Justify –Think Pair Share) THINKPAIR SHARE

Classifying lab How can methods of transportation be organized using a cladogram?

Phylogenetic Tree What organism is most primitive? What organisms would you say are closely related?

Check your understanding In this diagram, which organisms are most related to molluscs?

Check your understanding In this diagram, which organisms are most closely related to molluscs?

Check your understanding Are these cladograms the same? Why or why not?

Check your understanding Where is the ancestor of A, B and C?

Check your understanding Do flies and beetles have the same ancestor? Explain

Check your understanding Describe the relationship between clades and shared derived characters.

Check your understanding Describe the relationship between clades and shared derived characters. A derived character is one that emerges over time in a group of organisms and is the distinguishing trait between a diverging group, or clade, and the clades that have evolved previously. Every member of a clade can be traced back to a common ancestor that possessed and passed on that derived character.

Check your understanding What is the goal of cladistics?

Check your understanding What is the goal of cladistics? to arrange groups and species in the order in which they diverged from a common ancestor