1 classification. 2 why classify? to study the diversity of life, biologists use a classification...
TRANSCRIPT
![Page 1: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/1.jpg)
1
Classification
![Page 2: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/2.jpg)
2
Why Classify?
• To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner.
• In taxonomy, scientists classify organisms and assign each organism a universally accepted name.
• By using a scientific name, biologists can be certain that everyone is discussing the same organism.
![Page 3: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/3.jpg)
3
Aristotle 384 BC
• Classified organisms as either plants or animals
![Page 4: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/4.jpg)
4
Carolus Linnaeus 1707-1778
• Classification system• Based on physical
structure• Taxonomic groups of
related organisms• Binomial nomenclature
(two names ex.Homo sapiens)
![Page 5: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/5.jpg)
5
Binomial Nomenclature
• Carolus Linnaeus• In binomial nomenclature, each species
is assigned a two-part scientific name. – The scientific name is always written in italics
or underlined. – The first word (the genus) is capitalized – The second word (the species) is lowercased.EX- Genus species or Genus speciesHumans- Homo sapien
![Page 6: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/6.jpg)
6
Linnaeus's System of Classification
• A group or level of organization is called a taxonomic category, or taxon
• Linnaeus had 7-
Kingdom “King
Phylum Phillip
Class Came
Order Over
Family For
Genus Great
Species Spaghetti”
![Page 7: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/7.jpg)
7
Taxonomic Groups
![Page 8: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/8.jpg)
8
![Page 9: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/9.jpg)
9
Classification of Man
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• Species Homo sapiens
![Page 10: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/10.jpg)
10
Species
• “Species are groups of actually or potentially interbreeding populations, which are reproductively isolated from other such groups.”
• Reproductively isolated group
Ernst Mayr
![Page 11: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/11.jpg)
11
Different Species
![Page 12: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/12.jpg)
12
Checkpoint Questions:
1. How are living things organized for study?
2. Describe the system for naming species that Linnaeus developed.
3. What are the seven taxonomic categories of Linnaeus’s classification system?
4. Why do scientists avoid using common names when discussing organisms?
5. What is significant about members of the same species?
![Page 13: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/13.jpg)
13
Modern Evolutionary Classification
• Organisms are grouped into categories that represent lines of evolutionary descent, not just physical similarities
Modern classification systems are based upon biochemical and genetic evidence that indicates evolutionary relationships
![Page 14: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/14.jpg)
14
Classification Using Cladograms• Cladistic analysis identifies and considers only the
characteristics that arise as lineages evolve over time. – Characteristics that appear in recent parts of a lineage but
not in its older members are called derived characters.– Derived characters can be used to construct a cladogram,
a diagram that shows the evolutionary relationships among a group of organisms.
![Page 15: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/15.jpg)
15
Cladogram
• Evolutionary relationship of a group of organisms
• Each clad (group) share something in common
• Ancestral traits are the oldest
• Derived traits evolved later
![Page 16: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/16.jpg)
16
Cladogram for Transportation
• Wheels are the most ancestral
• Wings are the most derived
![Page 17: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/17.jpg)
17
Construct a Cladogram
![Page 18: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/18.jpg)
18
Gorilla
• Four limbs• Fur• Lost tail
![Page 19: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/19.jpg)
19
Tiger
• Four limbs• Fur• Tail
![Page 20: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/20.jpg)
20
Lizard
• Four limbs• Tail
![Page 21: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/21.jpg)
21
Fish
• Tail
![Page 22: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/22.jpg)
22
Chimpanzee
• Four limbs• Fur• Lost tail
![Page 23: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/23.jpg)
23
Clad With 4 Limbs
![Page 24: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/24.jpg)
24
Clad With Fur
![Page 25: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/25.jpg)
25
Clad With No Tail
![Page 26: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/26.jpg)
26
Characteristics for Constructing Cladogram
• Tail is the most ancestral
• Four limbs is the oldest derived trait
• Fur is a later derived trait
• Loss of tail is the most derived trait
![Page 27: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/27.jpg)
27
Gorilla Chimpanzee
Tiger
Lizard
Fish
Four Limbs
Fur
Tail Lost
![Page 28: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/28.jpg)
28
Gorilla Tail?
• How do we know the gorilla lost its tail?
![Page 29: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/29.jpg)
29
Gorilla’s Vestigial Tail
Gorilla Human
![Page 30: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/30.jpg)
30
TRADITIONAL CLASSIFICATION
CLADOGRAM
Appendages Conical Shells
Crab Barnacle Limpet Crab Barnacle Limpet
Crustaceans Gastropod
Molted exoskeleton
Segmentation
Tiny free-swimming larva
Section 18-2Traditional Classification Versus Cladogram
Go to Section:
![Page 31: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/31.jpg)
31
Modern Evolutionary Classification
• Similarities in DNA and RNA
– The genes of many organisms show important similarities at the molecular level that can be used as criteria to help determine classification.
![Page 32: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/32.jpg)
32
Modern Evolutionary Classification
• Molecular Clocks
– A model known as a molecular clock uses DNA comparisons to estimate the length of time that two species have been evolving independently.
• Comparison reveals more DNA in common, the more recent the common ancestor
![Page 33: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/33.jpg)
33
Terminology
• Classification– Assigning organisms to
different catagories based on their relationship
• Taxonomy– The science of naming
organisms
• Systematics– Determining evolutionary
relationships of organisms
• Phylogeny– Evolutionary history
![Page 34: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/34.jpg)
34
Phylogenetic Tree
• Shows evolutionary relationships
• More historical than cladogram
![Page 35: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/35.jpg)
35
MyxozoaMyxozoaMyxozoaMyxozoa
ArthropodaArthropodaArthropodaArthropoda AnnelidaAnnelidaAnnelidaAnnelida
MolluscaMolluscaMolluscaMollusca
LophophoratesLophophoratesLophophoratesLophophorates
HemichordataHemichordataHemichordataHemichordata
ChordataChordataChordataChordata
Other Other pseudocoelomatespseudocoelomates
Other Other pseudocoelomatespseudocoelomates
NematodaNematodaNematodaNematoda
PoriferaPoriferaPoriferaPorifera
CtenophoraCtenophoraCtenophoraCtenophoraCnidariaCnidariaCnidariaCnidaria
PlacozoaPlacozoaPlacozoaPlacozoa
PlatyhelminthesPlatyhelminthesPlatyhelminthesPlatyhelminthesNemerteaNemerteaNemerteaNemertea
CiliophoraCiliophoraCiliophoraCiliophoraSarcomastigophoraSarcomastigophoraSarcomastigophoraSarcomastigophora
MicrosporaMicrosporaMicrosporaMicrosporaApicomplexaApicomplexaApicomplexaApicomplexa
MesozoaMesozoaMesozoaMesozoa
EchinodermataEchinodermataEchinodermataEchinodermata
CrustaceaCrustaceaCrustaceaCrustaceaChelicerataChelicerataChelicerataChelicerata
UniramiaUniramiaUniramiaUniramia
ProtochordatesProtochordatesProtochordatesProtochordates
![Page 36: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/36.jpg)
36
Birds MammalsReptile
Amphibian
Fish
Four Limbs
Amniotic Egg
Endothermic
Fur
Feathers
Vertebrae
![Page 37: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/37.jpg)
37
Monophyletic
• A group of all the descendants of a common ancestor
• The common ancestor is in the group
• Example: Mammalia– Ancestor was a
mammal like reptile
![Page 38: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/38.jpg)
38
Paraphyletic
• A group of descendants of a common ancestor
• Common ancestor is in the group
• Not all descendants are included
• Example: Reptiles– Does not include birds
and mammals
![Page 39: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/39.jpg)
39
Polyphyletic
• A group that has some similarities
• Common ancestor is in not in the group
• Not all descendants are included
• Example: Flying vertebrates
![Page 40: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/40.jpg)
40
*
* Archaea
![Page 41: 1 Classification. 2 Why Classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical](https://reader035.vdocuments.net/reader035/viewer/2022062515/56649d0b5503460f949df041/html5/thumbnails/41.jpg)
41
Checkpoint Questions:
1. How is information about evolutionary relationships useful in classification?
2. How are genes used to help scientists classify organisms?
3. What is the principle behind cladistic analysis?
4. Describe the relationship between evolutionary time and the similarity of genes in two species.
5. How have new discoveries in molecular biology affected the way in which we classify organisms compared with the system used by Linnaeus?