Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 Classification. 2 There are 13 billion known species of organisms There are 13 billion known species of organisms This is only 5% of all organisms that.

Similar presentations


Presentation on theme: "1 Classification. 2 There are 13 billion known species of organisms There are 13 billion known species of organisms This is only 5% of all organisms that."— Presentation transcript:

1 1 Classification

2 2 There are 13 billion known species of organisms There are 13 billion known species of organisms This is only 5% of all organisms that ever lived!!!!! This is only 5% of all organisms that ever lived!!!!! New organisms are still being found and identified New organisms are still being found and identified I Species of Organisms

3 3 II What is Classification? 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

4 4 III Benefits of Classifying Accurately & uniformly names organisms Accurately & uniformly names organisms Prevents misnomers such as starfish & jellyfish that aren't really fish Prevents misnomers such as starfish & jellyfish that aren't really fish Uses same language (Latin or some Greek) for all names Uses same language (Latin or some Greek) for all names Sea”horse”??

5 5 Confusion in Using Different Languages for Names

6 6 Latin Names are Understood by all Taxonomists

7 7 IV Early Taxonomists 2000 years ago, Aristotle was the first taxonomist 2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into plants & animals Aristotle divided organisms into plants & animals He subdivided them by their habitat ---land, sea, or air dwellers He subdivided them by their habitat ---land, sea, or air dwellers

8 8 Early Taxonomists John Ray, a botanist, was the first to use Latin for naming John Ray, a botanist, was the first to use Latin for naming His names were very long descriptions telling everything about the plant His names were very long descriptions telling everything about the plant

9 9 Carolus Linnaeus 1707 – 1778 18th century taxonomist Classified organisms by their structure Developed naming system still used today

10 10 Carolus Linnaeus Called the “Father of Taxonomy” Called the “Father of Taxonomy” Developed the modern system of naming known as binomial nomenclature Developed the modern system of naming known as binomial nomenclature Two-word name (Genus & species) Two-word name (Genus & species)

11 11 V Standardized Naming Binomial nomenclature used Binomial nomenclature used Genus species Genus species Latin or Greek Latin or Greek Italicized in print Italicized in print Capitalize genus, but NOT species Capitalize genus, but NOT species Underline when writing Underline when writing Turdus migratorius American Robin

12 Scientific names help scientists to communicate. –Some species have very similar common names. –Some species have many common names.

13 13 Binomial Nomenclature Which TWO are more closely related?

14 14 Rules for Naming Organisms The International Code for Binomial Nomenclature contains the rules for naming organisms The International Code for Binomial Nomenclature contains the rules for naming organisms All names must be approved by International Naming Congresses (International Zoological Congress) All names must be approved by International Naming Congresses (International Zoological Congress) This prevents duplicated names This prevents duplicated names

15 15 VI Classification Groups Taxon ( taxa-plural) is a category into which related organisms are placed Taxon ( taxa-plural) is a category into which related organisms are placed There is a hierarchy of groups (taxa) from broadest to most specific There is a hierarchy of groups (taxa) from broadest to most specific Domain, Kingdom, Phylum, Class, Order, Family, Genus, species Domain, Kingdom, Phylum, Class, Order, Family, Genus, species

16 16 Hierarchy-Taxonomic Groups Domain Kingdom Phylum (Division – used for plants) Class Order Family Genus Species BROADEST TAXON Most Specific

17 17 Dumb King Phillip Came Over For Gooseberry Soup!

18 Domain: Eukarya copyright cmassengale18

19 19

20 The Domain Archaea has one Kingdom: The Domain Bacteria has one Kingdom: Eubacteria(true bacteria) Eubacteria(true bacteria) -found in practically every environment on earth -prokaryotes that have the same lipid in their cell membrane that eukaryotes have. -cell wall make of peptidoglycan Archaeabacteria(ancient bacteria) Archaeabacteria(ancient bacteria) -cell wall does not contain peptidoglycan -lipids are very different than bacteria and eukaryotes -seemed to have diverged very early from the bacteria domain, more similarities to eukaryotes than Bacteria domain Domains Broadest, most inclusive taxon Broadest, most inclusive taxon Three domains: Three domains:

21 21 Domain Eukarya is Divided into 4 Kingdoms Protista (protozoans, algae…) Protista (protozoans, algae…) Fungi (mushrooms, yeasts …) Fungi (mushrooms, yeasts …) Plantae (multicellular plants) Plantae (multicellular plants) Animalia (multicellular animals) Animalia (multicellular animals)

22 22 Protista Most are unicellular Most are unicellular Some are multicellular Some are multicellular Some are autotrophic, while others are heterotrophic Some are autotrophic, while others are heterotrophic Aquatic Aquatic Protists include all microscopic organisms that are not bacteria, not animals, not plants and not fungi. Protists include all microscopic organisms that are not bacteria, not animals, not plants and not fungi. Protists Ex. Paramecium, amoeba, alga,euglena Ex. Paramecium, amoeba, alga,euglena

23 23 Fungi Fungi Multicellular, except yeast Multicellular, except yeast Absorptive heterotrophs (digest food outside their body & then absorb it) Absorptive heterotrophs (digest food outside their body & then absorb it) Cell walls made of chitin Cell walls made of chitin Fungi are organisms that biologists once confused with plants, however, unlike plants, fungi cannot make their own food. Most obtain their food from parts of plants that are decaying in the soil. Fungi are organisms that biologists once confused with plants, however, unlike plants, fungi cannot make their own food. Most obtain their food from parts of plants that are decaying in the soil. Ex. Mushrooms, molds, yeast Ex. Mushrooms, molds, yeast

24 24 Plantae Multicellular Multicellular Autotrophic Autotrophic Absorb sunlight to make glucose – Photosynthesis Absorb sunlight to make glucose – Photosynthesis Cell walls made of cellulose Cell walls made of cellulose With over 250,000 species, the plant kingdom is the second largest kingdom. With over 250,000 species, the plant kingdom is the second largest kingdom. Ex. Trees, shrubs, flowers, mosses, ferns Ex. Trees, shrubs, flowers, mosses, ferns

25 25 Animalia Multicellular Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies) Ingestive heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals Feed on plants or animals The animal kingdom is the largest kingdom with over 1 million known species. The animal kingdom is the largest kingdom with over 1 million known species.animal ex. lions, tigers and bears ex. lions, tigers and bears

26 Eubacteria: Like archaebacteria, eubacteria are complex and single celled. Most bacteria are in the EUBACTERIA kingdom.eubacteria

27 Eubacteria: cont They are the kinds found everywhere and are the ones people are most familiar with. Eubacteria are classified in their own kingdom because their chemical makeup is different. Most eubacteria are helpful. Some produce vitamins and foods like yogurt. However, these eubacteria, Streptococci pictured above, can give you strep throat!

28 Archaebacteria: Archaebacteria In 1983, scientists tool samples from a spot deep in the Pacific Ocean where hot gases and molten rock boiled into the ocean form the Earth’s interior. To their surprise they discovered unicellular (one cell) organisms in the samples. These organisms are today classified in the kingdom, Archaebacteria.

29 Archaebacteria are found in extreme environments such as hot boiling water and thermal vents under conditions with no oxygen or highly acid environments. hot boiling water

30 Finding Archaebacteria: The hot springs of Yellowstone National Park, USA, were among the first places Archaebacteria were discovered. The biologists pictured above are immersing microscope slides in the boiling pool onto which some archaebacteria might be captured for study.

31 31

32 32 Taxons Most genera contain a number of similar species Most genera contain a number of similar species The genus Homo is an exception (only contains modern humans) The genus Homo is an exception (only contains modern humans) evolutionary relationships Classification is based on evolutionary relationships

33 33

34 34 Basis for Modern Taxonomy evolutionary relationships Classification is based on evolutionary relationships Homologous structures (same structure, different function) Homologous structures (same structure, different function) Similar embryo development Similar embryo development Molecular Similarity in DNA, RNA, or amino acid sequence of Proteins Molecular Similarity in DNA, RNA, or amino acid sequence of Proteins

35 KEY CONCEPT Organisms can be classified based on physical similarities.

36 Physical similarities are not always the result of close relationships. Genetic similarities more accurately show evolutionary relationships.

37 37 Homologous Structures (BONES in the FORELIMBS) shows Similarities in mammals.

38 38 Similarities in Vertebrate Embryos

39 39 Dichotomous Keying Used to identify organisms Used to identify organisms Characteristics given in pairs Characteristics given in pairs Read both characteristics and either go to another set of characteristics OR identify the organism Read both characteristics and either go to another set of characteristics OR identify the organism

40 40 Example of Dichotomous Key 1a Tentacles present – Go to 2 1b Tentacles absent – Go to 3 2a Eight Tentacles – Octopus 2b More than 8 tentacles – 3 3a Tentacles hang down – go to 4 3b Tentacles upright–Sea Anemone 4a Balloon-shaped body–Jellyfish 4b Body NOT balloon-shaped - 5

41 Cladistics is classification based on common ancestry. Phylogeny is the evolutionary history for a group of species. evidence from living species, fossil record, and molecular data shown with branching tree diagrams

42 Cladistics is a common method to make evolutionary trees. –classification based on common ancestry –species placed in order that they descended from common ancestor

43 43 Cladogram Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales

44 44 Primate Cladogram

45 A cladogram is an evolutionary tree made using cladistics. –A clade is a group of species that shares a common ancestor. –Each species in a clade shares some traits with the ancestor. –Each species in a clade has traits that have changed.

46 KEY CONCEPT Modern classification is based on evolutionary relationships.

47 Derived characters are traits shared in different degrees by clade members. –basis of arranging species in cladogram –more closely related species share more derived characters –represented on cladogram as hash marks FOUR LIMBS WITH DIGITS Tetrapoda clade 1 Amniota clade 2 Reptilia clade 3 Diapsida clade 4 Archosauria clade 5 EMBRYO PROTECTED BY AMNIOTIC FLUID OPENING IN THE SIDE OF THE SKULL SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW FEATHERS & TOOTHLESS BEAKS. SKULL OPENINGS BEHIND THE EYE DERIVED CHARACTER

48 FOUR LIMBS WITH DIGITS Nodes represent the most recent common ancestor of a clade. Clades can be identified by snipping a branch under a node. Tetrapoda clade 1 Amniota clade 2 Reptilia clade 3 Diapsida clade 4 Archosauria clade 5 EMBRYO PROTECTED BY AMNIOTIC FLUID OPENING IN THE SIDE OF THE SKULL SKULL OPENINGS IN FRONT OF THE EYE AND IN THE JAW FEATHERS AND TOOTHLESS BEAKS. SKULL OPENINGS BEHIND THE EYE NODE DERIVED CHARACTER CLADE

49 Molecular data may confirm classification based on physical similarities. Molecular data may lead scientists to propose a new classification. Molecular evidence reveals species’ relatedness. DNA is usually given the last word by scientists.DNA is usually given the last word by scientists.

50 KEY CONCEPT Molecular clocks provide clues to evolutionary history.

51 Molecular clocks use mutations to estimate evolutionary time. Mutations add up at a constant rate in related species. This rate is the ticking of the molecular clock. As more time passes, there will be more mutations. DNA sequence from a hypothetical ancestor The DNA sequences from two descendant species show mutations that have accumulated (black). The mutation rate of this sequence equals one mutation per ten million years. Mutations add up at a fairly constant rate in the DNA of species that evolved from a common ancestor. Ten million years later— one mutation in each lineage Another ten million years later— one more mutation in each lineage

52 Scientists estimate mutation rates by linking molecular data and real time. –an event known to separate species –the first appearance of a species in fossil record

53 Different molecules have different mutation rates.Different molecules have different mutation rates. –higher rate, better for studying closely related species –lower rate, better for studying distantly related species Mitochondrial DNA and ribosomal RNA provide two types of molecular clocks.

54 Mitochondrial DNA is used to study closely related species. grandparents parents child Nuclear DNA is inherited from both parents, making it more difficult to trace back through generations. Mitochondrial DNA is passed down only from the mother of each generation,so it is not subject to recombination. mitochondrial DNA nuclear DNA –mutation rate ten times faster than nuclear DNA –passed down unshuffled from mother to offspring

55 Ribosomal RNA is used to study distantly related species.Ribosomal RNA is used to study distantly related species. –many conservative regions –lower mutation rate than most DNA

56 KEY CONCEPT The current tree of life has three domains.

57 Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae Animalia Plantae

58 Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae –1866: all single- celled organisms moved to kingdom Protista Animalia Protista Plantae

59 Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae –1938: prokaryotes moved to kingdom Monera –1866: all single- celled organisms moved to kingdom Protista Animalia Protista Plantae Monera

60 The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae Classification is always a work in progress. –1938: prokaryotes moved to kingdom Monera –1866: all single- celled organisms moved to kingdom Protista Monera –1959: fungi moved to own kingdom Fungi Protista Plantae Animalia

61 The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae Classification is always a work in progress. –1938: prokaryotes moved to kingdom Monera –1866: all single- celled organisms moved to kingdom Protista –1959: fungi moved to own kingdom –1977: kingdom Monera split into kingdoms Bacteria and Archaea Animalia Protista Fungi Plantae Archea Bacteria

62 The three domains in the tree of life are Bacteria, Archaea, and Eukarya. Domains are above the kingdom level. proposed by Carl Woese based on rRNA studies of prokaryotes domain model more clearly shows prokaryotic diversity

63 Domain Bacteria includes prokaryotes in the kingdom Bacteria.Domain Bacteria includes prokaryotes in the kingdom Bacteria. –one of largest groups on Earth –classified by shape, need for oxygen, and diseases caused

64 –known for living in extreme environments Domain Archaea includes prokaryotes in the kingdom Archaea.Domain Archaea includes prokaryotes in the kingdom Archaea. –cell walls chemically different from bacteria –differences discovered by studying RNA

65 Domain Eukarya includes all eukaryotes.Domain Eukarya includes all eukaryotes. –kingdom Protista

66 Domain Eukarya includes all eukaryotes.Domain Eukarya includes all eukaryotes. –kingdom Protista –kingdom Plantae

67 Domain Eukarya includes all eukaryotes.Domain Eukarya includes all eukaryotes. –kingdom Protista –kingdom Plantae –kingdom Fungi

68 Domain Eukarya includes all eukaryotes.Domain Eukarya includes all eukaryotes. –kingdom Protista –kingdom Plantae –kingdom Fungi –kingdom Animalia

69 Bacteria and archaea can be difficult to classify.Bacteria and archaea can be difficult to classify. –transfer genes among themselves outside of reproduction –blurs the line between “species” –more research needed to understand prokaryotes bridge to transfer DNA

70 70


Download ppt "1 Classification. 2 There are 13 billion known species of organisms There are 13 billion known species of organisms This is only 5% of all organisms that."

Similar presentations


Ads by Google