Tecumseh High School ppt.pdfCarolus Linnaeus-used a two part Latin name called a binomal. ! First...

Opening Activity

!  Latin Root Word: Tax-

C L A S S I F Y I N G O R G A N I S M S

Taxonomy

Taxonomy

!  Taxnomy-involves identification, naming and classification of species

!  Carolus Linnaeus-used a two part Latin name called a binomal nomenclature.

Binomial Nomenclature

!  Species name has two parts (Genus and species identifier)

" Genus species " Homo sapiens = Humans

! Two part name = binomial nomenclature (Latin)

Why?

!  To overcome regional names.

!  Example: Mountain lions-depending on where you are, this creature has a different name.

!  Some names are deceiving: cat fish, crayfish, and silverfish

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Florida Panther

Cougar

The Linnaean classification system has limitations. !  Linnaeus taxonomy doesn’t account for molecular

evidence. !  The technology didn’t exist during Linneaus’ time. !  Linnaean system based only on physical similarities.

•  Physical similarities are not always the result of close relationships.

•  Genetic similarities more accurately show evolutionary relationships.

Classification

Evolutionary Categorization

!  Phylogenetic Tree-a diagram that reflects possible evolutionary relationships with branches to help classify organisms. !  Based on similarities in

the fossil record, stages of development, biomolecule similarities.

Cladistics - is a relatively new system of phylogenetics classification that uses shared derived characters to establish evolutionary relationships. A derived character is a feature that apparently evolved only within the group under consideration.

!  Cladistics is a common method to make evolutionary trees.

–  classification based on common ancestry –  species placed in order that they descended from common ancestor

A phylogenetic tree based on a cladistic analysis is called a cladogram.

What derived character is shared by all the animals on the cladogram on the next slide?

•  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

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

•  A key is a device for easily and quickly identifying an unknown organism.

•  The dichotomous key is the most widely used type of classification tool in biological sciences.

•  The user is presented with a sequence of choices between two statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed.

The Dichotomous Key

1.

A. one pair of wings

B. Two pairs of wings

Taxonomy

!  Taxnomy-involves identification, naming and classification of species

!  Carolus Linnaeus-used a two part Latin name called a binomal.

!  First part = genus !  Second part = speceis !  Example: Pantera onca

Classification

Things change

!  The classification system has undergone some changes due to advances in DNA technology

!  Originally, there were only two kingdoms, plants and animals.

!  What about protists, fungi and prokaryotes? !  Eventually ended up with the 6 kingdom system of

today, which are under the three domains.

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!




–  1866: all single-celled organisms moved to kingdom Protista

Animalia!

Protista!

Plantae!




–  1938: prokaryotes moved to kingdom Monera


Animalia!

Protista!

Plantae!

Monera!






Monera!–  1959: fungi moved to own kingdom

Fungi!

Protista!

Plantae!

Animalia!






–  1959: fungi moved to own kingdom

–  1977: kingdom Monera split into kingdoms Bacteria and Archaea

Animalia!

Protista!

Fungi!

Plantae!

Archea!

Bacteria

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

Six Kingdom System

!  Currently use two alternative classification systems !  6 Kingdom system

" Kingdom: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia

Kingdom Archaebacteria

!  Unicellular prokaryotes !  Archae- : “ancient”

!  Autotrophic: produce food by chemosynthesis !  Evolved before photosynthesis

!  Live in harsh environments !  Swamps, salt lakes, and hot springs

!  Methanogens: produce methane gas from H2 and CO2

!  Extreme Halophiles: salt loving !  Thermoacidophiles: live in acidic environments

(hot springs, hydrothermal vents)

Kingdom Eubacteria

!  “True Bacteria” ! Most use oxygen ! Unicellular prokaryotes ! Kingdom Eubacteria and Archaebacteria =

Greatest number of living things on earth ! Cause tooth decay, strep throat, food poisoning

(Salmonella) ! Accounts for most bacteria

Kingdom Protista

! Contains all Eukaryotes that are not plants, animals, or fungi !  Protozoa

" Phylum Sarcodina: Amoebas: amebic dysentery " Phylum Ciliophora: Paramecium " Phylum Zoomastigina: zooflagellates: Leishmaniasis " Phylum Sporozoa: Plasmodium: Malaria

!  algae !  slime molds !  water molds

Kingdom Fungi

!  Heterotrophic unicellular and multicellular organisms

!  Absorb nutrients instead of ingesting them !  Mushrooms, puffballs, rusts, smuts, mildews, and

molds.

Kingdom Plantae

!  Multicellular !  Autotrophic and use photosynthesis as a source of

energy !  Most live on land and have a sexual cycle based on

meiosis

Kingdom Animalia

!  Eukaryotic, multicellular, heterotrophic organisms !  Have symmetrical body organization !  Have standard sexual cycle based on meiosis and the

recombination of genes.

Three Domain System

! Compare sequences of ribosomal RNA in different organisms to estimate how long ago pairs of different organisms shared a common ancestor

! Domain Archae = Kingdom Archae bacteria (Prokaryotic)

! Domain Bacteria = Kingdom Eubacteria (Prokaryotic)

! Domain Eukarya = Kingdom Protista, Plantae, Fungi, Animalia (Eukaryotic)

•  Domain Bacteria includes prokaryotes in the kingdom Bacteria.

–  one of largest groups on Earth –  classified by shape, need for

oxygen, and diseases caused

–  known for living in extreme environments

•  Domain Archaea includes prokaryotes in the kingdom Archaea.

–  cell walls chemically different from bacteria

–  differences discovered by studying RNA

•  Domain Eukarya includes all eukaryotes.

–  kingdom Protista



–  kingdom Plantae




–  kingdom Fungi




–  kingdom Fungi

–  kingdom Animalia

•  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

Tecumseh High School ppt.pdfCarolus Linnaeus-used a two part Latin name called a binomal. ! First...

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