1. 5. Ecology and evolution
5.4 Classification

2. Some vocabulary
Phylogeny: the evolutionary history of a group of organisms.
Phylogenetic trees: formal hypotheses that identify likely relationships among species.
Taxonomy: the identification and naming of species and their placement in a classification.
Classification: an arrangement of organisms into hierarchical groups that reflect their relatedness
Taxon: The organisms included within any category of the taxonomic hierarchy
3. The Binomial System of Nomenclature
Carl von Linn (Carolus Linnaeus) invented a system in which species are assigned a two-part name, hence binomial.
The first part identifies a group of species with similar morphology: genus
The second part is the specific epithet or species
Ex.: Ursusmaritimus(polar bear), Pan troglodyte (chimpanzee), Homarusamericanus(lobster).
4. Rules for binomial nomenclature
the first name is the genus name
the genus name is always capitalized
the second name is the species name
the species name is not capitalized
italics are used if the name is printed
the name is underlined if handwritten
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5. Taxonomic Hierarchy
The taxonomic hierarchy Linnaeus defined is easily applied to Darwins
Arranges organisms into ever more inclusive categories or taxa. Largest to smallest:
Kingdoms : Prokaryotae, Protoctista, Fungi, Plantae and Animalia.
Phylum, Class, Order, Family, Genus, Species
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6. Blue Whale
Coast Redwood
Taxon
Kingdom
Phylum
Class
Order
Family
Genus
Species
Animalia
Chordata
Mammalia
Cetacea
Balaenopteridae
Balaenoptera
musculus
Plantae
Coniferophyta
Pinopsida
Pinales
Taxodiaceae
Sequoia
sempervirens
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7. 8. Traits of organisms as systematic characteristics
Linnaeus focused on external anatomy. Ex.: a bird is a class of oviparous (egg-laying) animals, with feathered bodies, two wings, two feet, and a bony beak. No other animals possess all these characteristics.
Two types of characteristics: morphological characters and behavioral characters
Molecular differences also help classify different organisms with similar characters
9. Examples using simple external recognition features
Plant classification:
Life cycle of a plant: male and female gametes fuse together zygote develops into an embryo how embryo develops depends on the type of plant it is
Four plant phyla:
Bryophyta mosses, livewortsand hornworts
Coniferophyta conifers
Filicinophyta ferns
Angiospermophyta flowering plants
10. * Indicates dispersal stage
11. Examples using simple external recognition features
Animal classification:
Life cycle of an animal: gametes fuse zygote develops into an embryo blastula different systems form, such as skeletal, nervous, digestive, blood, etc.
Animals are divided into over 30 phyla based on their characteristics
Examples of 6 phyla
12. Examples from six animal phyla
13. Arthropoda
With jointed legs & segmented body.
Have a hard exoskeleton made up of chitin.
True champions of diversity & adaptation as they have conquered most habitat world wide.
There are over a million species of arthropods worldwide.
Eg.: insects, spiders, scorpions & crustacean like crabs & shrimps.
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14. Time to put you to the test!
From the following pictures:
Study the organisms and assign each one to its phylum
2. List the organisms that are
A) bilaterally symmetric
B) radially symmetric
C) not symmetrical in their structure
3. List the organisms that have
Jointed appendages
Stinging tentacles
Bristles
4. List the organisms that filter feed by pumping water through tubes inside their bodies.
15. Invertebrate diversity
Alcyoniumglomeratum
Pycnogonumlittorale
Adociacinerea
Nymphongracilis
16. Invertebrate diversity
Lepidonotusclava
Corynactisviridis
Polymastiamammiliaris
Cyaneacapillata
17. Invertebrate diversity
Caprellalinearis
Loligoforbesii
Procedoreslittoralis
Gammaruslocusta
Arenicola marina
Prostheceraeusvittatus
18. Dichotomus key
It consists of a numbered series of pairs of descriptions to help assign a species to the correct group.
One description should clearly match the species and the other should clearly be wrong. They should be reliable and easily visible.
Each description leads either to another numbered pair in the key, or to an identification
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19. Dichotomuskey, example
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20. Dichotomos keys, homework
Apply and design a key for the ten organisms in your handout based on their footprints.