Taxonomy Environmental Ed. 1. Taxonomy The science of naming and classifying organisms.
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Taxonomy
Environmental Ed. 1
Taxonomy
• The science of naming and classifying organisms.
Linnaean taxonomy
• Named after Swedish botanist Carolus Linnaeus
• Classifies organisms based on their physical and structural similarities
• Uses Binomial Nomenclature
Binomial Nomenclature
• System that gives each species a two-part scientific name using Latin words.
• First part: genus
• Second part: species
• Ex: Puma concolor
• Common name: mountain lion, cougar, puma
• Scientific name: Puma Concolor
Linnaeus’ Classification System Has 7 Levels
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
Linnaean Classification System
If two species belong to the same order, what other levels in the
Linnaean system must they have in common?
• Kingdom• Phylum• Class• Order• Family• Genus• Species
If two species belong to the same order, what other levels in the
Linnaean system must they have in common?
• Kingdom• Phylum• Class• Order• Family• Genus• Species
• ANSWER: Kingdom, Phylum, Class
What limitations may the Linnaean system have?
• This system focuses on physical similarities alone
• Before technology allowed us to study organisms at the molecular level.
• Does not account for similarities that evolved through convergent evolution.
EX: the Red Panda which is more closely related to raccoons than Giant Panda’s.
Cladistics
• Classification based on common ancestry
• Uses evidence from living species, the fossil record, and molecular data
• Phylogeny: evolutionary history for a group of species.
Cladogram
• An evolutionary tree that proposes how species may be related to each other through common ancestors.
Animal Diversity
• Each animal Phylum has a unique body plan
• Animals are grouped using a variety of criteria
• A comparison of structure and genetics reveals the evolutionary history of animals.
Vertebrates
• An animal with an internal segmented backbone
• Most obvious animals around us
• Make up less than 5% of all known animal species
Invertebrates
• Animals without a backbone
• Most are not closely related to each other
Phylum Chordata
• Contains all vertebrates and some invertebrates
• Vertebrates: large, active animals that have a well-developed brain encased in a hard skull.
• Tunicates: urochordates, including both free-swimming and sessile animals such as sea squirts.
• Lancelets: cephalochordates, small eel-like animals that are commonly found in shallow tropical oceans.
Tunicates
Lancelets
Chordates share 4 common features- at some stage of development
1. Notochord: flexible skeletal support rod embedded in the animal’s back.
2. Hollow nerve chord: runs along the animal’s back
3. Pharyngeal slits: through the body wall in the pharynx. Water can enter the mouth and leave without passing through the entire digestive system.
4. Tail: contains segments of muscle tissue used for movement.
Endoskeleton
• An internal skeleton built of bone or cartilage
Vertebrate Classes
• Agnatha
• Chondrichthyes
• Osteichthyes
• Amphibia
• Reptilia
• Aves
• Mammalia
Class Agnatha
• Oldest class of vertebrates
• Jawless animals• Include lampreys, a
type of fish
Class Chondrichthyes
• Cartilaginous fish
• Animals include sharks, rays and chimeras
Class Osteichthyes
• Bony Fish• Have skeletons made
of bone
Class Amphibia
• First vertebrates adapted to live both in water and on land
• Include salamanders, frogs, toads, and caecilians
Class Reptilia
• Able to retain moisture, lets them live exclusively on land.
• Produce eggs• Include snakes,
lizards, crocodiles, alligators, and turtles
Class Aves
• Birds• Presence of feathers
Class Mammalia
• Animals that have hair, mammary glands, and three middle ear bones.
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