Classification

1. Classification SC.912.L. 15.6 Discuss distinguishing characteristics of the domain and kingdoms of living organisms. CC: RST. 11-12.1, SL.11-12.4, MP.4

2. How do we name these similar but different animals? Polar bears and Brown Bears are their common names but how can we scientifically name them? How do you know the cat on the left? Puma Mountain lion Florida panther Cougar Puma concolor= cougar Puma concolorcoryi= florida panther

4. Dichotomous Key • Used to identify organisms • Series of paired statements or questions that describe alternative possible characteristics of an organism.

5. Linnaean Classification System • System that organized species into taxa that formed a hierarchy or set of ordered ranks.

7. Problems with Traditional Classification • Linnaeaus System is based on similarities and differences • The crab, barnacles, and limpet share some similarities and differences. • Under traditional classification, crabs would be classified into a separate group. BUT LOOKS can be deceiving!

8. Look more closely! LIMPET BARNACLE Limpet and barnacle larvae are very different. Barnacles have jointed limbs. Limpets DON’T ! Barnacles have a segmented body Limpets DON’T ! Barnacles have an exoskeleton that molts. Limpets DON’T ! CRAB

9. Look more closely! LIMPET CRAB BARNACLE Crab and barnacle larvae are very similar Barnacles have jointed limbs. So do CRABS ! Barnacles have a segmented body So do CRABS ! Barnacles have an exoskeleton that molts. So do CRABS !

10. Limpets have an internal anatomy more like snails, which are MOLLUSKS. Because of these characteristics, scientists have concluded that barnacles are more closely related to crabs than to MOLLUSKS LIMPET SNAIL

11. BOTH crabs and barnacles have been classified as CRUSTACEANS • Scientists today try to assign species to a larger group in ways that reflect how closely members of those groups are related to each other.

12. Modern Classification • Evolutionary Classification- grouping organisms based on evolutionary history. • Phylogeny: evolutionary history of lineages. • Common ancestors get placed in higher taxa • whose members are more closely related to • one another than to any other group. • This classification system groups organisms • into groups called CLADES. Clades- group of species that includes 1. single common ancestor 2. and all descendants of that ancestor—living and extinct.

13. CLADOGRAMS Links groups of organisms by showing how evolutionary lines, or lineages, branches off from common ancestors. • Derived Characters- a trait that arose in the most recent common ancestor of a particular lineage and was passed along to its descendants. • certain kinds of characters are looked at when assigning organisms into clades unlike Linnaeaus classification.

14. Interpreting Cladograms

15. Traditional VS. Modern Classification • Linnaean Class Reptilia is not a clade because it does NOT include modern birds. • Birds are descendants of reptiles, which can be seen from the cladogram on the right!

16. DNA in Classification • Genes can be derived characters. • The more derived GENETIC characters two species share, the more recently they shared a common ancestor and the more closely they are related in evolutionary terms.

17. The NEXT SLIDE WILL SAVE YOU ON THE EOC… COPY IT DOWN!!!

19. Words To Know: • Prokaryote- unicellular organism that lacks a nucleus • Eukaryote- organisms whose cells contain a nucleus • Peptidoglycan- serves a structural role in the walls of bacteria. • Cellulose- provides strength and rigidity to plant cells • Chitin- tough, protective covering or structural support for certain organisms. • Chloroplast- organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy. • Multicellular- two or more cells in an organism • Unicellular- organism is made up of one cell. • Autotroph- organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds—producer. • Heterotroph- organism that obtains food by consuming other living things—consumer.