classification of living things
Post on 02-Dec-2014
43 Views
Preview:
DESCRIPTION
TRANSCRIPT
CLASSIFICATION OF
LIVING THINGS
• THE NEED FOR CLASSIFICATION
• SHORT HISTORY OF CLASSIFICATION
• THE CLASSIFICATION SYSTEM
• Binomial System of Nomenclature
• Levels of Classification
• The Concept of Species
• BASES FOR GROUPING ORGANISMS
• SCHEMES OF CLASSIFICATION
INSTRUCTIONS
With a partner, view this slideshow on classification systems. You will be asked to answer 26 questions along the way. Keep your answers concise (brief but comprehensive), please!
The deadline for your answers is 5:00 p.m. TODAY. Remember, LATE = ZERO!
Lastly, please observe proper behavior in the library! Thank you.
THE NEED FOR CLASSIFICATION:
WHY CLASSIFY?
Taxonomic
group
Species Endemic
species
Percent
endemism
Plants 9,253 6,091 65.8
Mammals 167 102 61.1
Birds 535 186 34.8
Reptiles 237 160 67.5
Amphibians 89 76 85.4
Freshwater
fishes 281 67 23.8
Diversity and Endemism in the Philippines
To work with the diversity of life, we need a system of biological
classification that names and orders organisms in a logical
manner.
Q1. What is endemism?
Q2. What do the figures in the table above say about
endemism in our country?
Q3. Give the scientific names of the Philippine endemic
species pictured in this slide.
Two important features of a biological classification system:
1. Assigns a universally accepted name to each organism
THE NEED FOR CLASSIFICATION:
WHY CLASSIFY?
Left: common buzzard (Europe)
Right: turkey buzzard (N. America)
Q4. These two birds are
commonly known as
‘buzzards’. Give the
scientific name of each
buzzard.
Q5. Why is it important that
the assigned name is
‘universally accepted’?
Two important features of a biological classification system:
2. Places organisms into groups that have real biological
meaning
THE NEED FOR CLASSIFICATION:
WHY CLASSIFY?
Artificial classification Natural classification
• Uses only one or a few
characteristics
• Superficial
• Uses as many
characteristics as possible
• Can show evolutionary
relationships
THE NEED FOR CLASSIFICATION:
WHY CLASSIFY?
• Taxonomy
• Branch of biology that deals with the identification,
classification, and naming of organisms
• Major objectives
• To sort out closely related organisms and assigns them to separate species
• To order species into the broader taxonomic categories: genera to kingdoms
• Phylogeny
• The evolutionary history of a species or group of species
• Systematics = taxonomy + phylogenetics
• The study of biological diversity in the context of evolutionary
history
• Major objective: to have classification reflect the evolutionary
affinities of species
SHORT HISTORY
OF CLASSIFICATION
1. Early attempts at classification
• Two major groups: plant & animal kingdom
• Plants – grasses, herbs, trees, etc.
• Animals – fish, creeping creatures, fowl, beasts, cattle
Q6. Why is it that only plants and animals were
included in this classification system?
SHORT HISTORY
OF CLASSIFICATION
2. 4th century B.C.
• Aristotle classified animals
• Air dwellers, land dwellers, water dwellers
• Theophrastus classified plants
• Herbs (soft stems), shrubs (several woody stems),
trees (single woody stem)
Q7. What was the basis of Aristotle for
classifying animals? How about that of
Theophrastus for classifying plants?
SHORT HISTORY
OF CLASSIFICATION
3. Mid-1600s
• John Ray (English naturalist) was the first to use
the term species
• Species: a group of organisms that were structurally
similar and that passed these similarities on to their
offspring
• Genus: a group of closely related species
SHORT HISTORY
OF CLASSIFICATION
4. 18th century
• Scientific names in Latin
• Long names as detailed descriptions of the
physical characteristics of an organism
• Cumbersome and difficult to standardize
Q8. What is the old, polynomial scientific name of the fruit in the
picture, and what did it mean? How about its binomial scientific
name?
SHORT HISTORY
OF CLASSIFICATION
4. Carolus Linnaeus
• Swedish botanist
• Father of modern taxonomy
• Used structural similarities as a basis
for his classification system
Q9. This man standardized how we name each organism, though
he himself goes by many names. Give as many as you can.
Q10. Write something about the controversial ‘sexual system’ that
Linnaeus devised as a means of classification.
THE CLASSIFICATION SYSTEM
THE NAMING SYSTEM OF CAROLUS LINNAEUS:
BINOMIAL NOMENCLATURE
• Pre-Linnaean nomenclature:
• Genus name + many descriptive Latin words
• Rosa sylvestris alba cum rubore, folioglabro
(pinkish white woodland rose with hairless leaves)
• Rosa sylvestris inodora seu canina (odorless
woodland dog rose)
Q11. The polynomial names above both refer to the flower
pictured above. Give the current scientific name of this flower, and
give as many of its common names as you can.
THE CLASSIFICATION SYSTEM
THE NAMING SYSTEM OF CAROLUS LINNAEUS:
BINOMIAL NOMENCLATURE
• Binomial: two-part name
Nomenclature: system of naming things
• Two-part name:
• Genus/generic name
• Capitalized
• Species name/specific epithet
• Starts w/ lower-case letter
• Usually a Latin description of some important
characteristic of the organism
Pithecophaga jefferyi
Philippine eagle
• Gr. pithecus, “ape or
monkey” + phagein,
“eater of”
• Jeffrey Whitehead, father
of English explorer and
naturalist John
Whitehead
THE CLASSIFICATION SYSTEM
THE NAMING SYSTEM OF CAROLUS LINNAEUS:
BINOMIAL NOMENCLATURE
Conventions for using binomials and names of higher
taxonomic categories
A. Capitalize
1. Genus, but not the species
2. Latin names of categories above genus level, but not their English
counterparts
B. Italicize or underline
1. Genus & species, but not above genus level (whether Latin or English)
Examples:
Varanus mabitang or Varanus mabitang
Reptilia, reptiles
Q12. Give the common name
of Varanus mabitang
THE CLASSIFICATION SYSTEM
THE NAMING SYSTEM OF CAROLUS LINNAEUS:
BINOMIAL NOMENCLATURE
Conventions for using binomials and names of higher
taxonomic categories
C. Spell out
1. The generic name the first time it is used in each paragraph
2. The specific epithet every time it is used
D. Abbreviate
1. The generic name to its first letter at the second and subsequent
mentions in the same paragraph.
2. When the genus but not the species of the organism(s) is known. (In
this case, always spell out the genus name, even if it was already
mentioned previously in the same paragraph.)
Examples:
V. mabitang or V. mabitang
Varanus sp. (one unknown species), Varanus spp. (more than one unknown species)
THE CLASSIFICATION SYSTEM
LEVELS OF CLASSIFICATION
Q13. Write down an original mnemonic device to help aid in
memorizing the correct hierarchy of taxonomic groups: domain,
kingdom, phylum, class, order, family, genus, species
THE CLASSIFICATION SYSTEM
THE CONCEPT OF SPECIES
Q14. Complete the sentence: Morphology is the study of _____.
Earlier concepts of “species”
• Morphological concept: emphasizes measurable anatomical
differences between species
• Simply a rank (the lowest category) in Linnaeus’ hierarchy of
taxonomic categories
THE CLASSIFICATION SYSTEM
THE CONCEPT OF SPECIES
Biological Species Concept (BSC) by Ernst Mayr (1942)
• “Species are groups of interbreeding natural populations, which are
reproductively isolated from other such groups.”
• “This species is called biological not because it deals with biological
taxa, but because the definition is biological. It utilizes criteria that are
meaningless as far as the inanimate world is concerned.”
• Earlier concepts were based on properties that could also be applied to
noniving things
• Linnaeus recognized species of rocks and minerals based on degree of difference.
THE CLASSIFICATION SYSTEM
THE CONCEPT OF SPECIES
Biological Species Concept (BSC) by Ernst Mayr (1942)
• A true biological concept must be based on properties unique to
biological systems
• Ex. Reproduction and interbreeding – species are separated from one
another due to reproductive barriers
Q15. Match each of the reproductive barriers above with their correct
description. (Note: You need not memorize this part, just FYI.)
1. Habitat isolation
2. Temporal isolation
3. Behavioral isolation
4. Mechanical isolation
5. Gametic isolation
6. Reduced hybrid viability
7. Reduced hybrid sterility
8. Hybrid breakdown
A. Courtship rituals
B. Hybrids may be sterile
C. Occupy different habitats
D. Morphological differences
E. Breed at different times of the day, different seasons,
etc.
F. Sperm of one sp. may not be able to fertilize eggs of
another sp.
G. Hybrid offspring of different parent spp. do not
complete development
H. First-generation hybrids may be fertile, but subsequent
generations are feeble or sterile
THE CLASSIFICATION SYSTEM
THE CONCEPT OF SPECIES
• The species is the only category with a clear biological
identity. For other categories, different scientists have different
ideas about which characteristics are biologically most
important.
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
1. Structural information
Ex. fishes: class Agnatha, class Chondrichthyes, class Osteichthyes
Amphiprion sp.
(clownfish)
Petromyzon marinus
(sea lamprey)
Taeniura lymma
(blue-spotted ribbontail ray)
Q16. What structural features qualifies a fish as a member of class
Agnatha? class Chondrichthyes? class Osteichthyes?
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
2. Cytological information
Ex. fungi and plants
Amanita muscaria
(fly agaric)
Papaver somniferum
(opium poppy)
Q17. What is one major difference between fungal and plant cells?
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
3. Embryological information
Ex. phylum Chordata
Early stages of development
in vertebrate embryos:
(1) fish, (2) chicken, (3) pig, (4) human
Q18. Chordates are named for a skeletal structure present in all
chordate embryos as well as in some adult chordates. What is this
structure and what is it for?
1
2
3
4
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
4. Behavioral information
Ex. African vultures, American vultures, and storks
Gyps africanus
(African vulture)
Q19. What does the dragonfly book say about the peculiar behavior of
and possible relationship between two of these birds?
Coragyps atratus
(American vulture)
Mycteria americana
(Florida wood stork)
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
5. Biochemical information
Myosin is a protein found
in muscle cells.
Yeasts don’t have muscles,
but why do they have
myosin?
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
5. Biochemical information
• Taxonomists use molecular similarities and
differences to classify organisms. Why can they
do this?
• All forms of life (except some viruses) carry genetic
information in the form of DNA
• The DNA of all organisms share a common genetic
code.
• Genes and gene products (proteins) of living
organisms descended from genes of common
ancestors
• Differences in nucleotide/amino acid sequences
were produced by mutations that occurred after the
ancestors of the living species diverged.
Q20. Visit this link to learn how to transcribe and translate a
gene. For this question, your answer would be the amino acid
sequence of the protein you synthesized. -
http://learn.genetics.utah.edu/content/begin/dna/transcribe/
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
5. Biochemical information
• If two species diverged hundreds of millions of years ago, there has been lots of
time for mutations to alter the structure of DNA/protein.
• If two species shared common ancestors until fairly recently, their DNA/protein
will have similar sequences.
Q21. Based on the
diagram to the right,
what can you say about
the difference in amino
acid sequence between
two species compared to
the fossil evidence of
their common ancestor?
What does this have to
do with their taxonomic
classification?
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
6. Evolutionary relationships
• As supported by paleontology
• Pakicetus: extinct genus of cetaceans; early ancestor of modern whales
• Beluga whale: modern cetacean
• Aetiocetus: intermediate between ancestral Pakicetus form and modern beluga
Q22. Complete the sentence: Paleontology is the study of _____.
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
6. Evolutionary relationships
• As supported by homology
Q23. According to this link, what is homology?
http://evolution.berkeley.edu/evolibrary/article/similarity_ms_01
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
6. Evolutionary relationships
• As supported by homology
Systematists attempt to group organisms in ways that show their
evolutionary relationships, not just physical similarities
• similarities more recent common ancestor
• Homologous structures are due to
divergent evolution / adaptive
radiation • One species gives rise to many species
that appear different externally but are
similar internally
• Analogous structures are due to
convergent evolution
• Unrelated organisms independently
evolve similarities when adapting to
similar environments
General rule:
• # of homologous parts between 2 spp., closely related
• complex two similar structures are, likely it is they have evolved
independently
THE CLASSIFICATION SYSTEM
BASES FOR GROUPING ORGANISMS
6. Evolutionary relationships
• Phylogenetic trees and cladograms: branched diagrams that show
evolutionary history of related species
Phylogenetic tree:
branch lengths correspond
to time estimates
Cladogram: only represents
branching pattern; branch lengths
do not correspond to time
SCHEMES OF CLASSIFICATION
• As in all areas of science, ideas and models in
taxonomy change as new information and
technology arises
• Arranging the diversity of life into kingdoms is a
work in progress.
SCHEMES OF CLASSIFICATION
TWO-KINGDOM SYSTEM (1700S)
Plantae Green, photosynthetic
organisms that used
energy from the sun
Animalia Mobile organisms that
used food for energy
SCHEMES OF CLASSIFICATION
THREE-KINGDOM SYSTEM (1800S)
Plantae Green,
photosynthetic
organisms that used
energy from the sun
Animalia Mobile organisms
that used food for
energy
Monera Microorganisms
Q24. What technological
advancement paved the way
for the addition of a new
kingdom, Monera?
SCHEMES OF CLASSIFICATION
FOUR-KINGDOM SYSTEM (1950S)
Plantae Green,
photosynthetic
organisms that used
energy from the sun
Animalia Mobile organisms
that used food for
energy
Fungi With cell walls
of chitin
Monera Microorganisms
SCHEMES OF CLASSIFICATION
FIVE-KINGDOM SYSTEM (EARLY 1990S)
Eukaryotic
Prokaryotic
Fungi Animalia
Plantae
Protista
Monera Q25. Give one major
similarity and one major
difference between protists
and monerans.
SCHEMES OF CLASSIFICATION
THREE-DOMAIN SYSTEM (EARLY 1990S)
Eukaryotic
Prokaryotic
Fungi Animalia
Plantae
Protista
ARCHAEA BACTERIA
EUKARYA
Q26. According to
this link, what
molecular evidence
shows that Archaea is
more related to
Eukarya than to
Bacteria? -
http://bcs.whfreeman.
com/thelifewire/conte
nt/chp27/27020.html (Choose “step-through”
instead of “narrated” if there
is no audio in the library PCs)
SCHEMES OF CLASSIFICATION
DOMAIN Bacteria Archaea Eukarya
KINGDOM (Eubacteria) (Archae-
bacteria) Protista Fungi Plantae Animalia
CELL
TYPE
Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
CELL
STRUCTURES
Cell walls w/
peptidoglycan
Cell walls w/o
peptidoglycan
Cell walls of
cellulose;
some have
chloroplasts
Cell walls of
chitin
Cell walls of
cellulose;
with chloroplasts
No cell walls nor
chloroplasts
# OF CELLS Unicellular Unicellular Most unicellular;
some colonial;
some
multicellular
Most
multicellular;
some unicellular
Multicellular Multicellular
MODE OF
NUTRITION
Autotroph or
heterotroph
Autotroph or
heterotroph
Autotroph or
heterotroph
Heterotroph Autotroph Heterotroph
EXAMPLES Streptococcus,
Escherichia coli
Methanogens,
halophiles
Amoeba,
Paramecium,
slime molds,
giant kelp
Mushrooms,
yeasts
Mosses, ferns,
flowering plants
Sponges,
worms, insects,
fishes, mammals
END OF
SLIDESHOW
IMAGE SOURCES
• Slide 2
• Question mark – http://www.istockphoto.com/stock-photo-7651615-question-mark.php
• Email – http://www.shutterstock.com/pic-57235357/stock-photo-the-email-icon-sending-an-email.html
• Angel – http://nicecliparts.com/images-Sweat_Baby_Angels.php
• Slide 3
• Rafflesia – http://www.arkive.org/rafflesia/rafflesia-spp/
• Philippine crocodile – http://www.arkive.org/philippine-crocodile/crocodylus-mindorensis/image-G25800.html
• Tamaraw – http://www.arkive.org/tamaraw/bubalus-mindorensis/
• Philippine eagle – http://www.arkive.org/philippine-eagle/pithecophaga-jefferyi/image-G25801.html
• Slide 4
• European buzzard - http://en.wikipedia.org/wiki/File:Buteo_buteo_-Scotland-8.jpg
• N. American buzzard - http://en.wikipedia.org/wiki/File:Urubu_a_tete_rouge_-_Turkey_Vulture.jpg
• Slide 8
• Aristotle - http://www.gap-system.org/~history/PictDisplay/Aristotle.html
• Theophrastus - http://www.iep.utm.edu/theophra/
IMAGE SOURCES
• Slide 9
• John Ray - http://en.wikipedia.org/wiki/File:John_Ray_from_NPG.jpg
• Slide 10
• Tomato - http://en.wikipedia.org/wiki/File:Bright_red_tomato_and_cross_section02.jpg
• Slide 11
• Linnaeus -
http://en.wikipedia.org/wiki/File:Carolus_Linnaeus_by_Hendrik_Hollander_1853.jpg
• Slide 12
• Dog rose - http://en.wikipedia.org/wiki/File:Divlja_ruza_cvijet_270508.jpg
• Slide 13
• Philippine eagle - http://www.arkive.org/philippine-eagle/pithecophaga-jefferyi/image-
G112223.html
IMAGE SOURCES
• Slide 14
• Monitor lizard - http://www.terrarium-nature.com/articles.php?lng=fr&pg=483
• Slide 16
• Examples of taxonomic categories - http://en.wikipedia.org/wiki/Taxonomic_rank
• Slide 21
• Blue-spotted ribbontail ray - http://en.wikipedia.org/wiki/Taeniura_lymma
• Lamprey - http://en.wikipedia.org/wiki/Lamprey
• Clownfish - http://www.incredibleaquarium.com/index.php?main_page=index&cPath=31_45_63
• Slide 22
• Fly agaric - http://en.wikipedia.org/wiki/Fly_agaric
• Opium poppy - http://www.dailymail.co.uk/news/article-1028504/The-opium-fields-England--heroin-
producing-poppies-grown-make-NHS-pain-relief-drugs.html
• Slide 23
• Embryos - http://www.millerandlevine.com/km/evol/embryos/Haeckel.html
IMAGE SOURCES
• Slide 24
• African vulture - http://en.wikipedia.org/wiki/White-backed_Vulture
• American vulture - http://en.wikipedia.org/wiki/Black_Vulture
• Florida wood stork - http://en.wikipedia.org/wiki/Wood_Stork
• Slide 25
• Muscular system - http://www.medicalook.com/human_anatomy/systems/Muscular_system.html
• Yeast cells - http://www.sciencenews.net.au/using-yeast-cells-to-run-calculations/
• Slide 26
• Central dogma - http://faculty.ksu.edu.sa/al-saleh/Pictures%20Library/Central%20Dogma.jpg
• Genetic code - http://www.thetwentyfirstfloor.com/?p=722
• Slide 27
• Diagram - http://www.bio.miami.edu/dana/106/106F05_4print.html
• Slide 28
• Fossils - http://evolution.berkeley.edu/evosite/lines/IAtransitional.shtml
IMAGE SOURCES
• Slide 29
• Homologous limbs - http://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_03
• Slide 31
• Phylogenetic tree – Biology by Solomon
• Cladogram - http://bakerbiology.wikispaces.com/Cladograms
top related