classification of living things

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


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


WHY CLASSIFY?

Artificial classification Natural classification

• Uses only one or a few

characteristics

• Superficial

• Uses as many

characteristics as possible

• Can show evolutionary

relationships


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.




• 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




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




Conventions for using binomials and names of higher


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)


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

http://en.wikipedia.org/wiki/Mnemonic


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




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.



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 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.


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?



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?



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



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)



5. Biochemical information

Myosin is a protein found

in muscle cells.

Yeasts don’t have muscles,

but why do they have

myosin?




• 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/







• 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?



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 _____.




• As supported by homology

Q23. According to this link, what is homology?

http://evolution.berkeley.edu/evolibrary/article/similarity_ms_01







• 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




• 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.


TWO-KINGDOM SYSTEM (1700S)

Plantae Green, photosynthetic

organisms that used

energy from the sun

Animalia Mobile organisms that

used food for energy


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?


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


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.


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)

http://bcs.whfreeman.com/thelifewire/content/chp27/27020.html






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

classification of living things

Documents

means of classification

classification systems

classification system

term species species

philippine endemic species

group of species systematics

binomial nomenclature

concept of species bases