1. Classification 1

2.  Evolution has lead to a large variety of organisms.  Biologists have identified and named about 1.5 million species so far.  They estimate anywhere between 2 and 100 million additional species have yet to be discovered. 2

3.  The science of classifying and naming organisms.  Goal – organize living things into groups that have biological meaning.  This ensures that everyone is talking about the same organism.  Uses accepted names and common criteria to group things. “Teacher” or “Mechanic” “Biology Teacher” or “Auto Mechanic” 3

4.  18th century- European scientists recognized that referring to organisms by common names was confusing.  Common names vary among regions within a country. In UK buzzard refers to a hawk In the US buzzard refers to a vulture 4

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7.  First attempts at standard scientific names often described physical characteristics.  As a result, these names could be 20 words long!  The English translation of the scientific name of a particular tree might be “Oak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges.” 7

8.  Carolus Linnaeus (18th Century) – a Swedish botanists. Hierarchical system that consists of 7 levels/taxa (taxon). Currently there are now 8 levels. 8

9. Domain Kingdom Phylum Class Order Family Genus species Largest / Least Specific Smallest / Most Specific Taxon :A group or level of organization 9

10. Domain Kingdom Phylum Class Order Family Genus species  Did  King  Phillip  Come  Over  For  Good  Soup 10

11. DOMAIN Eukaryota 11

12.  Developed by Linnaeus.  Two-word naming system.  Assigns a two-part scientific name. Universally accepted Written in Greek and Latin Written in italics First word is capitalized Second word is lowercased Composed of a genus and species Example:  Canis lupis  C. lupis 12

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14.  Organisms determine who belongs to their species by choosing with whom they will mate!  Taxonomic groups above species are “invented” by researchers.  Sometimes, due to Convergent Evolution organisms that are quite different from each other evolve similar body structures.  Example: Crab, limpet, barnacle 14

15. 15 Crabs Barnacles Limpets

16.  Darwin’s theory of evolution changed the entire way that biologists thought about classification.  Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities. Phylogeny  Species within a genus are more closely related then species within another genus. 16

17.  Many biologists now prefer a method called cladistic analysis.  This method of classification identifies and considers only those new characteristics that arise as lineages evolve over time.  Derived characteristics - Characteristics that appear in recent parts of a lineage but not in its older members. 17

18. Things to know: -Location of “circles” represent when a characteristic first appeared. -Derived traits determine the grouping of organisms. -Help scientists understand how one lineage might have branched from another. CLADOGRAM- a diagram which shows evolutionary relationships among a group of organisms.

19. Cladogram 19 A splitting event – called a node Descendants Derived character

20. 20 Cladogram

21.  Suppose you were trying to compare diverse organisms such as yeast and humans.  It wouldn’t make sense to try to classify anatomical similarities.  The genes of many organisms show important similarities at the molecular level.  These similarities can be used as criteria to help determine classification.  Example: Myosin in humans & yeast 21

22.  American vultures have a behavior similar to storks. Urinate on legs when overheated.  Evaporative cooling  Scientists analyzed DNA. Share more similarities in DNA. Common ancestor American vulture shares a common ancestor with a stork over the African vulture. 22

23.  Before Linnaeus’s time, the only two Kingdoms that existed were Plants and Animals.  As scientists discovered new organisms that didn’t fit into the plant or animal category, they made new categories.  Microorganisms got the kingdom - Protista  Mushrooms, yeast and mold were separated from plants – and made into Fungi. 23

24. 1. Bacteria  Kingdom Eubacteria 2. Archaea  Kingdom Archaebacteria 3. Eukarya  Kingdom Protists, fungi, plantae, animalia (Everything with a nucleus) 24

25. Unicellular Prokaryotic Live in Extreme environments Volcanic Hot springs Some need oxygen (Aerobic), others live in oxygen deprived (Anaerobic) environments Cell walls lack peptidoglycan Autotroph or Heterotroph Asexual reproduction- binary fission

26.  Unicellular  Prokaryotic - no nucleus, no membrane bound organelles.  Cell walls with peptidoglycan.  Some autotrophic/some heterotrophic.  Important decomposers.  Asexual reproduction.  Found in soil, water, on / inside humans.  Some cause disease, others help make chemicals to help humans fight disease causing bacteria. 26

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28.  Consists of all organisms that have a nucleus.  The four kingdoms include: Protista Fungi Plantae Anamalia 28

29. 1. Monera - Bacteria 2. Protist 3. Fungi 4. Plants 5. Animals 29

30.  Recently, biologists come to recognize that the Monera (bacteria) were composed of two distinct groups Eubacteria and Archaebacteria 30