Sylvia S. Mader Copyright © The McGraw Hill Companies Inc. Permission required for reproduction or display PowerPoint® Lecture Slides are prepared by Dr. Isaac Barjis, Biology Instructor BIOLOGY 10th Edition Systematics & Phylogeny Chapter 19: pp Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (All): © Sylvia S. Mader

2 Outline Taxonomy Binomial System Species Identification Classification Categories Phylogenetic Trees Systematics Taxonomy (naming of organisms) Classification (placing species in the proper categories) Systematics Today Cladistic Systematics Phenetic Systematics Classification Systems The Five Kingdom System The Three Domain System

3 Taxonomy Taxonomy is the branch of biology concerned with identifying, naming, and classifying organisms. A natural system of classification reflects the evolutionary history of organisms. Naming and identifying organisms began with the Greeks and Romans. Aristotle classified organisms into groups such as horses, birds, and oaks In the Middle Ages, organisms were described using long Latin descriptions. John Ray ( ), Argued that each organism should have a set name. Otherwise, “men…cannot see and record accurately.”

4 Classifying Organisms Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (All): © Sylvia S. Mader

5 Taxonomy: Binomial System Mid-eighteenth century, Linnaeus developed the binomial system of nomenclature First word is genus name Second word is specific epithet Refers to one species (of potentially many) within its genus A species is referred to by the full binomial name (Genus species) Genus name can be used alone to refer to a group of related species

6 Carolus Linnaeus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: Courtesy Uppsala University Library, Sweden; b: © Arthur Gurmankin/Visuals Unlimited; c: © Dick Poe/Visuals Unlimited a. b. Lilium canadensec. Lilium bulbiferum

7 Taxonomy: Distinguishing Species Distinguishing species on the basis of structure can be difficult Members of the same species can vary in structure Attempts to demonstrate reproductive isolation is problematic because: Some species hybridize, and Reproductive isolation is difficult to observe

8 Classification Categories Aristotle classified life into 14 groups (e.g., mammals, birds, etc.), Ray grouped animals and plants according to how he thought they were related. Modern taxonomists use the following classification: Species Genus – one or more species Family – one or more genera Order – one or more families Class – one or more orders Phylum – one or more classes Kingdom – one or more phyla Domain – one or more kingdoms

9 Hierarchy of Taxa for Parthenocissus quinquefolia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DOMAINS Eukarya KINGDOMS Plantae PHYLA Anthophyta Eudicotyledones CLASSES Vitales ORDERS Parthenocissus SPECIES Parthenocissus quinquefolia Virginia creeper (five-leaf ivy) Vitaceae FAMILIES GENERA P. quinquefolia

10 Classification Categories The higher the category, the more inclusive Organisms in the same domain have general characteristics in common Members of a species share quite specific characters. A character is any structural, chromosomal, or molecular feature that distinguishes one group from another In most cases, classification categories can be subdivided into additional categories Superorder Order Suborder Infraorder

11 Phylogenetic Trees Systematics is the study of diversity of organisms using information from cellular to population levels One goal of systematics is to determine phylogeny (evolutionary history) of a group Phylogeny is the evolutionary history of a group of organisms. Phylogeny often represented as a phylogenetic tree A diagram indicating lines of descent Each branching point: Is a divergence from a common ancestor Represents an organism that gives rise to two new groups

12 Classification and Phylogeny Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. monkeysapes common ancestor (mobile limbs) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. reindeermonkeysapes common ancestor (placental mammal)

13 Classification and Phylogeny Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Aepycero s Melampus (impala) Aepyceros Oryx Cervus Rangifer Cervidae Bovidae Artiodactyla Genus Species Family Order Oryx gazella (oryx) Cervus elaphus (red deer) Rangifer tarandus (reindeer)

14 Phylogenetic Trees Classification lists the unique characters of each taxon and is intended to reflect phylogeny Primitive characters: Present in all members of a group, and Present in the common ancestor Derived characters: Present in some members of a group, but Absent in the common ancestor

15 Cladistic Systematics Cladistics analyze primitive and derived characters and constructs cladograms on the basis of shared derived characters. Arrange taxa into a cladogram A cladogram is a special type of phylogenetic tree A clade is an evolutionary branch that includes: A common ancestor, together with All its descendent species It traces the evolutionary history of the group being studied. Constructing a Cladogram First step: construct a table of characters of the taxa being compared. Any character found in the outgroup as well is a shared primitive character. Homologies shared by certain lineages are shared derived characters.

16 Constructing a Cladogram Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. chimpanzeedogfinchcrocodilelizardfrogtuna lancelet (outgroup) Species Traits mammary glands gizzard epidermal scales amniotic egg four limbs vertebrae hair ingroup notochord in embryo

17 Constructing a Cladogram: Phylogenetic Tree vertebrae four limbs feathers gizzard hair, mammary glands long canine teeth enlarged brain chimpanzee tuna frog lizard crocodile finch terrier lancelet (outgroup) common ancestor epidermal scales Amniotic egg common ancestor Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

18 Parsimony Cladists are guided by the principle of parsimony—the minimum number of assumptions is most logical. The best cladogram is one in which the fewest number of shared derived characters are left unexplained or that minimizes the number of assumed evolutionary changes. Reliability of cladograms is dependent on the knowledge and skill of a investigator.

19 Different Grouping of Species common ancestor A B C D E F H I G A B C D E F H I G A B C D E F H I G Monophyletic grouping: This group is a clade because it contains B, closest common ancestor, and all the descendants of B. Paraphyletic grouping: This group is not a clade because it lacks F, also a descendant of the common ancestor B. Polyphyletic grouping: This group is not a clade because it lacks A, the closest common ancestor to all the descendants. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

20 Terms Used in Cladistics

21 Tracing Phylogeny Fossil Record Fossil record is incomplete It is often difficult to determine the phylogeny of a fossil Homology Refers to features that stem from a common ancestor Homologous structures are related to each other through common descent Analogy Similarity due to convergence

22 Ancestral Angiosperm © David Dilcher and Ge Sun paired stamens fruits Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

23 Tracing Phylogeny Convergent Evolution The acquisition of a feature in distantly related lines of descent The feature is not present in a common ancestor Similar structures are due to adaptation to the same type environment Parallel Evolution The acquisition of a feature in two or more related lineages The feature is not present in a common ancestor

24 Development Reveals Homologies Vertebrate (modern bony fish) anus Echinoderm (sea star) Anus develops from blastopore in both Adult sea star Similar embryos blastopore Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

25 Molecular Data Protein Comparisons Immunological techniques Degree of cross reaction used to judge relationship Amino acid sequencing Similar sequence in same protein indicates close relationship RNA and DNA Comparisons Systematics assumes: Two species with similar base-pair sequences are assumed to be closely related Two species with differing base-pair sequences are assumed to be only distantly related Molecular Clocks Use non adaptive nucleotide sequences Assumed constant rate of mutation over time

26 Molecular Data Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. human PRESENT white-handed gibbon rhesus monkey green monkey capuchin monkey Million years ago (MYA) Increased difference in DNA common chimpanzee

27 Science Focus: DNA Bar Coding of Life Traditionally, taxonomists relied on anatomical data Consortium for the Barcode of Life (CBOL), allows all scientists to be able to identify a species with the flick of a handheld scanner. Like the 11-digit Universal Product Code (UPC) used in a supermarket, DNA is UPC of organism on Earth. DNA–bar-coding device provides a fast and inexpensive way to catalog organisms.

28 Identifying Spiders Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a.b. a: © Brent Opell; b: © Kjell B. Sandved/Visuals Unlimited

29 Three-Domain System Sequencing of rRNA suggests all organisms evolved along three distinct lineages: Domain Bacteria Prokaryotic unicellular organisms that reproduce asexually. Cyanobacteria are large photosynthetic prokaryotes. Most bacteria are heterotrophic. Important in ecosystems - keeping chemical cycling going. Some bacteria are parasitic and cause disease. Domain Archaea Prokaryotic unicellular organisms that reproduce asexually. Live in extreme environments Cell wall is diverse but not the same as the bacterial cell wall.

30 Three-Domain System Domain Eukarya Unicellular and multicellular organisms Cells with a membrane-bounded nucleus Sexual reproduction common Contains four kingdoms Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia

31 Tree of Life Showing The Three Domains Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. common ancestor ARCHAEA BACTERIA EUKARYA animalsfungi plants cyanobacteria protists heterotrophic bacteria

32 Major Difference of Three Domains

33 The Three Domains of Life Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (Bacteria): © David M. Phillips/Visuals Unlimited; (Archaea): © Ralph Robinson/Visuals Unlimited; (Flower): © Ed Reschke/Peter Arnold, Inc.; (Paramecium): © M. Abbey/Visuals Unlimited; (Mushroom): © S. Gerig/Tom Stack & Associates; (Wolf): © Art Wolf/Stone/Getty Images Domain Eukarya Protists Paramecium, Paramecium Domain Eukarya Kingdom Fungi Mushroom, Hygrocybe Domain Eukarya Kingdom Plantae Black-eyed Susan, Rudbeckia Domain Bacteria Escherichia Domain Archaea Methanosarcina Domain Eukarya Kingdom Animalia Grey wolf, Canis

34 Review Taxonomy Binomial System Species Identification Classification Categories Phylogenetic Trees Systematics Taxonomy (naming of organisms) Classification (placing species in the proper categories) Systematics Today Cladistic Systematics Phenetic Systematics Classification Systems The Five Kingdom System The Three Domain System

Sylvia S. Mader Copyright © The McGraw Hill Companies Inc. Permission required for reproduction or display PowerPoint® Lecture Slides are prepared by Dr. Isaac Barjis, Biology Instructor BIOLOGY 10th Edition Systematics & Phylogeny Chapter 19: pp Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (All): © Sylvia S. Mader