10-1 CHAPTER 10 Taxonomy and Phylogeny of Animals Taxonomy and Phylogeny of Animals

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CHAPTER 10CHAPTER 10CHAPTER 10CHAPTER 10

Taxonomy and Taxonomy and Phylogeny of Phylogeny of

AnimalsAnimals

Taxonomy and Taxonomy and Phylogeny of Phylogeny of

AnimalsAnimals

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Linnaeus and TaxonomyLinnaeus and Taxonomy

More than More than 1.5 million species of animals1.5 million species of animals are are namednamed Estimated that these account forEstimated that these account for

Less than Less than 20% of all animals currently alive20% of all animals currently alive Less than Less than 1% of extinct animals1% of extinct animals

Taxonomy (aka - Systematics) Taxonomy (aka - Systematics) Formal system for naming and classifying speciesFormal system for naming and classifying species Science of classifying organisms based on Science of classifying organisms based on

similarity, biogeography, etc.similarity, biogeography, etc.


Systematics

3 types of Systematics/Taxonomy Evolutionary Systematics

Grouping organisms that resemble ancestors Numerical Taxonomy

Used mathematical models to group organisms according to overall similarities

Phylogenetic Systematics (cladistics) Use “outgroups”, differences between taxa to make a

subset called a clade (Greek - branch) Most commonly used, measures variety of

characteristics. *Discussed later*


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Greek philosopher Greek philosopher Aristotle Aristotle first classified first classified organisms (350 BC)organisms (350 BC)

Carolus LinnaeusCarolus Linnaeus designed the current designed the current system of classification (1750)system of classification (1750) Swedish botanistSwedish botanist with extensive experience with extensive experience

classifying objects, especially flowersclassifying objects, especially flowers Used morphology (study of form and structure) to Used morphology (study of form and structure) to

develop a classification system of animals and develop a classification system of animals and plants plants

Divided animal kingdom into Divided animal kingdom into speciesspecies and gave and gave each a distinctive nameeach a distinctive name

Grouped speciesGrouped species into genera, genera into orders, and into genera, genera into orders, and orders into classesorders into classes

His classification scheme has been drastically His classification scheme has been drastically altered, but the altered, but the basic principle is still followedbasic principle is still followed


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CarolusLinnaeus


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Hierarchy of taxonomic ranks now includes Hierarchy of taxonomic ranks now includes 7 major 7 major groupsgroups Kingdom, phylum, class, order, family, genus, and Kingdom, phylum, class, order, family, genus, and

speciesspecies Now, the new level of Now, the new level of DomainDomain is also used. is also used. All animals are placed in All animals are placed in Kingdom Animalia, or Kingdom Animalia, or

Domain EukaryaDomain Eukarya Taxa (Taxon) - Taxa (Taxon) - Groups of animals that share a Groups of animals that share a

particular set of characteristics.particular set of characteristics. Example: True Flies “Diptera” - single pair of Example: True Flies “Diptera” - single pair of

wingswings Each rank can be subdivided into additional levels Each rank can be subdivided into additional levels

of taxaof taxa Superclass, suborder, etc. Superclass, suborder, etc.



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Linnaeus

1735

2 kingdomsHaeckel

1866[5]

3 kingdoms

Chatton

1937[6]

2 empires

Copeland

1956[7]

4 kingdoms

Whittaker

1969[2]

5 kingdoms

Woese et al.

1977[3]

6 kingdoms

Woese et al.

1990[8]

3 domains

Eubacteria BacteriaProkaryota Monera Monera

Archaebacteria Archaea(not treated) Protista

Protista ProtistaProtista

Fung i Fung iVegetab ilia Plantae

Plantae Plantae Plantae

Animalia Animalia

Euka ryota

Animalia Animalia Animalia

Euka rya

Division of Life - Milestones


3 Domains - current proposal

Based on ribosomal RNA sequences


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Nomenclature:Nomenclature: assignment of a distinctive assignment of a distinctive name to each speciesname to each species

A A scientific name of an animal scientific name of an animal consists ofconsists of two two words (binomial nomenclature) words (binomial nomenclature) First word is theFirst word is the genus genus and is and is capitalizedcapitalized Second is the Second is the speciesspecies written in written in lower caselower case

Scientific name should be Scientific name should be printed in italics or printed in italics or underlinedunderlined if handwritten if handwritten Homo sapiensHomo sapiens Homo sapiensHomo sapiens

TaxonomyTaxonomy


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Some animals are subspecies, usually Some animals are subspecies, usually caused by Geographic locations. They are caused by Geographic locations. They are referred to as referred to as trinomials (3 names)trinomials (3 names) All threeAll three terms are in terms are in italicsitalics SubspeciesSubspecies is also in is also in lower case lower case Ex. Ex. Ensantina eschscholtziiEnsantina eschscholtzii (salamander) has (salamander) has

many subspecies.many subspecies. E.e. plantens, E.e. picta, E.e.croceaterE.e. plantens, E.e. picta, E.e.croceater

TaxonomyTaxonomy



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SpeciesSpecies

Biological Biological SpeciesSpecies Concept Concept Been refined and reworded several times Been refined and reworded several times

A species is a reproductive community of A species is a reproductive community of populations (reproductively isolated from populations (reproductively isolated from others) that occupies a specific niche in others) that occupies a specific niche in nature.nature.

Ability to Ability to successfully interbreedsuccessfully interbreed is central is central to the conceptto the concept


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SpeciesSpecies

Biologists use certain criteria for identifying Biologists use certain criteria for identifying speciesspecies

Common DescentCommon Descent Reproductive CommunityReproductive Community

Member of a species must form a Member of a species must form a reproductive community that reproductive community that excludes members of other speciesexcludes members of other species


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Cladogram Cladogram Diagram illustrating hierarchy of clades (groups Diagram illustrating hierarchy of clades (groups

of animals with common ancestry)of animals with common ancestry) To construct a To construct a Phylogenetic treePhylogenetic tree

Additional information concerning ancestors, Additional information concerning ancestors, duration of lineages, and amount of evolutionary duration of lineages, and amount of evolutionary change must be included (compared to change must be included (compared to cladogram)cladogram)

Taxonomic Characters and Phylogenetic ReconstructionTaxonomic Characters and Phylogenetic Reconstruction


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A cladogram

Amphioxus is the “outgroup” because it doesn’t share any of the defining characteristic with the other taxa. What characteristic separates Bass from Horses?


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Sources of Sources of PhylogeneticPhylogenetic Information Information (What do we use to identify animals??)(What do we use to identify animals??)

Comparative Morphology Comparative Morphology Examines shapes, sizes and development of Examines shapes, sizes and development of

organismsorganisms Skull bones, limb bones, scales, hair and Skull bones, limb bones, scales, hair and

feathers feathers Living specimensLiving specimens and and fossilsfossils are used are used



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Comparative BiochemistryComparative Biochemistry Analyzes sequences of amino acids in proteins Analyzes sequences of amino acids in proteins

and nucleotides sequences in nucleic acidsand nucleotides sequences in nucleic acids Recent studies show comparative biochemistry Recent studies show comparative biochemistry

can be applied to fossilscan be applied to fossils

Comparative Cytology Comparative Cytology Examines variation in number, shape and size Examines variation in number, shape and size

of chromosomes of chromosomes Used Used almost exclusively on living specimensalmost exclusively on living specimens



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Phylogenetic Tree basedOn Cytology: Comparing base substitutions on Cyctochrome C (a respiratory protein).#’ s represent number of Mutations that occurred.


Animal Kingdom Patterns of Organization

Symmetry Asymmetrical (no central

body point/axis) ex. sponge

Bilateral (if divided right/left sides are mirror image) ex. vertebrates

Radial (any plane cut through organism makes mirror image) ex. Sea anemone

Embryonic Tissue Layers: Diploblastic - 2 tissues

(ectoderm and endoderm)

Triploblastic - 3 tissue layers (also mesoderm)

Zygote Cleavage Protostome - blastopore

becomes mouth Deuterostome -

blastopore becomes anus



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Major Subdivisions of the Animal KingdomMajor Subdivisions of the Animal Kingdom

Traditional groupings based on embryological Traditional groupings based on embryological and anatomical charactersand anatomical characters

Branch (Parazoa): Branch (Parazoa): phylum Porifera, phylum Porifera, the sponges the sponges and and phylum phylum PlacozoaPlacozoa

Branch (Eumetazoa): all other phylaBranch (Eumetazoa): all other phyla


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Branch EumetazoaBranch Eumetazoa Grade I (Radiata): phyla CnidariaGrade I (Radiata): phyla Cnidaria Grade II (Bilateria): all other phylaGrade II (Bilateria): all other phyla

Division A (Protostomia):Division A (Protostomia): (subdivisions made by (subdivisions made by presence of coelom in embryo)presence of coelom in embryo)

Acoelomates: phyla Platyhelminthes, Acoelomates: phyla Platyhelminthes, Pseudocoelomates: phyla Rotifera, Nematoda, Pseudocoelomates: phyla Rotifera, Nematoda, Eucoelomates: phyla Mollusca, Annelida, Eucoelomates: phyla Mollusca, Annelida,

Arthropoda, Tardigrada, Arthropoda, Tardigrada, Division B (Deuterostomia):Division B (Deuterostomia):

phyla Echinodermata, Chordataphyla Echinodermata, Chordata



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Recent molecular Phylogenetic studies have Recent molecular Phylogenetic studies have challenged traditional classification of Bilateriachallenged traditional classification of Bilateria Grade II: BilateriaGrade II: Bilateria

Division A: (Protostomia):Division A: (Protostomia):(subdivisions made by (subdivisions made by molting/shedding)molting/shedding)

Lophotrochozoa (non-molting): phyla Lophotrochozoa (non-molting): phyla platyhelminthes, Rotifera, Mollusca, Annelida, platyhelminthes, Rotifera, Mollusca, Annelida,

Ecdysozoa (outer covering sheds or molts): phyla Ecdysozoa (outer covering sheds or molts): phyla Nematoda, Arthropoda, Tardigrada, Nematoda, Arthropoda, Tardigrada,

Division B (Deuterostomia): Division B (Deuterostomia): phyla Chordata, phyla Chordata, EchinodermataEchinodermata


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10-1 CHAPTER 10 Taxonomy and Phylogeny of Animals Taxonomy and Phylogeny of Animals