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Taxonomy. The science of naming and classifying organisms. Carl Linnaeus developed the scientific naming system still used today. Binomial nomenclature is a two-part scientific naming system. uses Latin words scientific names always written in italics or underlined
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Taxonomy The science of naming and classifying organisms
Carl Linnaeus developed the scientific naming system still used today • Binomial nomenclature is a two-part scientific naming system. • uses Latin words • scientific names always written in italics or underlined • two parts are the genus name and species descriptor
Tyto alba and Quercus alba Are these species related?
Barn owl: Tyto alba White oak:Quercus alba
A genus includes one or more physically similar species. • Species in the same genus are thought to be closely related. • Genus name is always capitalized. • A species descriptor is the second part of a scientific name. • always lowercase • always follows genus name; never written alone
Ursus maritimus Ursus maritimus Ursus arctos horribilis (horribilis is the subspecies)
Match the Latin names with the descriptions • Big-horned sheep from Canada • Bird with blue-green wings • House sparrow • An extinct human that walked upright • Tree with large flowers • Passer domesticus • Homo erectus • Cyanopicacyana • Magnolia grandiflora (e) Oviscanadensis
Scientific names help scientists to communicate. • Some species have very similar common names. • Some species have many common names.
How can you remember these levels? • Kingdom __________ • Phylum __________ • Class __________ • Order __________ • Family __________ • Genus __________ • Species __________
video • Tree of Life
BioEd Online Taxonomic Diagrams Mammals Turtles Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Birds PhylogeneticTree Cladogram
Cladistics is classification based on common ancestry. • Phylogeny is the evolutionary history for a group of species. • evidence from living species, fossil record, and molecular data • shown with branching tree diagrams
derived traits are shown with numbers 1-4- organisms are shown with letters A-D
1) Which traits do the Sinornis and Velociraptor share? 2) Which animal has the most traits? 3) Does the Allosaurus have down feathers?
Make a cladogram Alligator: amniotic egg, bones, four limbs, jaws, vertebrae Frog: bones, four limbs, jaws, vertebrae Gull: amniotic egg, bones, feathers, four limbs, jaws, vertebrae Lamprey: vertebrae Shark: jaws, vertebrae Swordfish: bones, jaws, vertebrae
1 a) oval leaf: go to 2 b) lobed leaf: go to 5 2 a) leaf w/smooth edge: go to 3 b) leaf w/serrate or “sawtooth” edge: go to 4 3 a) leaf 10 to 15 cm long. . . . . magnolia b) leaf 4 to 7 cm long . . . . . . . common pear 4 a) leaf 10 to 15 cm long . . . . Spanish chestnut b) leaf 4 to 7 cm long . . . . . . white elm 5 a) four or five lobes: go to 6 b) many lobes: go to 7
1 a) oval leaf: go to 2 b) lobed leaf: go to 5 2 a) leaf w/smooth edge: go to 3 b) leaf w/serrate or “sawtooth” edge: go to 4 3 a) leaf 10 to 15 cm long . . . . . magnolia b) leaf 4 to 7 cm long . . . . . common pear 4 a) leaf 10 to 15 cm long . . . . . Spanish chestnut b) leaf 4 to 7 cm long . . . . . white elm 5 a) four or five lobes: go to 6 b) more than 5 lobes: go to 7
6 a) four pointy lobes . . . . . tulip tree b) five pointy lobes: go to 8 7 a) lobes pointy . . . . . red oak b) lobes rounded . . . English oak 8 a) star-shaped leaf . . . . sweetgum tree b) leaf not star-shaped . . . Japanese maple
Common Latin noun endings • -a, -us, -um, -ae, -i, -is, -o
Mutations add up at a fairly constant rate in the DNA of species that evolved from a common ancestor. Ten million years later— one mutation in each lineage Another ten million years later— one more mutation in each lineage Molecular clocks use mutations to estimate evolutionary time. • Mutations add up at a constant rate in related species. • As more time passes, there will be more mutations. The DNA sequences from two descendant species show mutations that have accumulated (black). The mutation rate of this sequence equals one mutation per ten million years. DNA sequence from a hypothetical ancestor
grandparents mitochondrial DNA nuclear DNA parents Mitochondrial DNA is passed down only from the mother of each generation,so it is not subject to recombination. child Nuclear DNA is inherited from both parents, making it more difficult to trace back through generations. • Mitochondrial DNA is used to study closely related species. • mutation rate ten times faster than nuclear DNA • passed down unshuffled from mother to offspring
Evidence for molecular clockin Hemoglobin Quoll = Large carnivorous marsupial
Plantae Animalia Classification is always a work in progress. • The tree of life shows our most current understanding. • New discoveries can lead to changes in classification. • Until 1866: only two kingdoms,Animalia and Plantae
Protista • Until 1866: only two kingdoms,Animalia and Plantae Plantae Animalia • 1866: all single-celled organisms moved to kingdom Protista
Plantae Animalia Protista Monera • Until 1866: only two kingdoms,Animalia and Plantae • 1866: all single-celled organisms moved to kingdom Protista • 1938: prokaryotes moved to kingdom Monera
Plantae Animalia Protista Fungi • Until 1866: only two kingdoms,Animalia and Plantae • 1866: all single-celled organisms moved to kingdom Protista • 1938: prokaryotes moved to kingdom Monera • 1959: fungi moved to own kingdom Monera
Plantae Animalia Protista Archea Bacteria Fungi • Until 1866: only two kingdoms,Animalia and Plantae • 1866: all single-celled organisms moved to kingdom Protista • 1938: prokaryotes moved to kingdom Monera • 1959: fungi moved to own kingdom • 1977: kingdom Monerasplit into kingdoms Bacteria and Archaea
The three domains in the tree of life are Bacteria, Archaea, and Eukarya. • Domains are above the kingdom level. • proposed by Carl Woese based on rRNA studies of prokaryotes • domain model more clearly shows prokaryotic diversity
Domain Bacteria includes prokaryotes in the kingdom Bacteria. • one of largest groups on Earth • classified by shape, need for oxygen, and diseases caused
Domain Archaea includes prokaryotes in the kingdom Archaea. • cell walls chemically different from bacteria • known for living in extreme environments
Domain Eukarya includes all eukaryotes. • kingdom Protista
Domain Eukarya includes all eukaryotes. • kingdom Protista • kingdom Plantae
Domain Eukarya includes all eukaryotes. • kingdom Protista • kingdom Plantae • kingdom Fungi
Domain Eukarya includes all eukaryotes. • kingdom Protista • kingdom Plantae • kingdom Fungi • kingdom Animalia