Transcript Chapter 18 Classification

Chapter 18 Classification
18.1 Finding Order in Diversity
• Systematics – science of naming and grouping organisms
• Binomial Nomenclature – two word naming system started by Carolus
Linnaeus to describe and name each species
• Each species is give a two part name:
First part = Genus Second part = species
• Both are either underlined or italicized: ex: Genus species or Genus species
• Names are in Latin so they are universal
• Ex. Human = Homo sapiens
• System expanded to include 7 taxa
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Kingdom
Phylum
Class
Order
Family
Genus
Species
18.2Modern Evolutionary Classification
• Evolutionary Classification – the study of evolutionary relationships among
organisms; called PHYLOGENY
• Phylogeny- the study of how living and extinct organisms are related to one
another
• Classify/group organisms into categories that reflect lines of
evolutionary descent rather than overall similarities and differences
• Place organisms into higher taxa based on relatedness
• Clade – a group of species that includes a single common ancestor (living and
extinct)
• Use Derived Characteristics to assign species to clades
• A trait that arose in the most recent common ancestor
of a particular lineage and was passed along to its
descendants
• Ex: Felidae clade = retractable claws
18.2Modern Evolutionary Classification
Cladograms – diagrams that show how species and higher
taxa are related to each other
• Shows evolutionary lines, or lineages, branched off from a
common ancestor
• Places where the lineage spits is called a fork or node
• Nodes represents the point where new lineages last
shared a common ancestor
• The root (at the bottom) represents the ancestor
shared by all of the organism on the cladogram
• Relies of derived characters
• Building a Cladogram constructing a cladogram ws
Based on the cladogram, are amphibians more
closely related to humans or to ray-finned fish?
18.2Modern Evolutionary Classification
• What are the derived
characters in the cladogram
and which groups have those
characters?
18.2Modern Evolutionary Classification
• DNA is Classification
• All organisms have DNA, which can be compared in different species.
• The more derived genetic characteristics two species share, the more
recently the species shared a common ancestor and the more closely
related they are.
18.3 Building the Tree of Life
• The tree of life shows current hypotheses regarding evolutionary
relationships among taxa within the three domains of life
• Current 3 Domain and 6 Kingdom System
18.3 Building the Tree of Life
DOMAINS OF LIFE
• 3 Domains of Life
• Archaea (prokaryotic)
• Bacteria (prokaryotic)
• Eukarya (eukaryotic)
DOMAIN BACTERIA
Prokaryotic
Unicellular
Cell walls contain peptidoglycan
Ecologically diverse ranging from freeliving soil organisms to deadly parasites.
• Some autotrophic, some heterotrophic
• Some need oxygen to survive (aerobic),
some are killed by oxygen (anaerobic)
• Only one kingdom within this domain:
Kingdom Eubacteria
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DOMAIN ARCHAEA
Prokaryotic
Unicellular
Cell walls do NOT contain peptidoglycan
Live in very harsh environments
Some autotrophic, some heterotrophic
Some need oxygen to survive (aerobic),
some are killed by oxygen (anaerobic)
• Only one kingdom within this domain:
Kingdom Archaebacteria
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IMPORTANCE OF PROKARYOTES
1) Ecological Importance: Essential in maintaining every
aspect of the ecological balance of the living world
• Decomposers – recycling raw materials to the
environment, essential to sewage treatment & production
of purified water
• Producers – cyanobacteria are among the most plentiful
photosynthetic organisms in the world & many food chains
are dependent upon them
• Nitrogen Fixers – converting nitrogen gas into useable
forms
2) Human Uses
• Food – yogurt, other dairy products
• Medicine – making drugs for medical treatments
3) Disease – some bacteria can cause disease by destroying
living cells or by releasing chemicals that upset homeostasis
• EX’s/ Lyme disease, Tetanus, Tuberculosis, Strep Throat
• Controlled by sterilization, disinfectants
• Prevented by vaccines
DOMAIN EUKARYA
• All Eukaryotes: contain a nucleus & other membrane-bound
organelles
• Four Kingdoms
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Protista (protists)
Fungi
Plantae
Animalia
PROTISTS
• Unicellular, Colonial, or Multicellular
• Photosynthetic or Heterotrophic
• Catchall kingdom – group of eukaryotes
that did not fit into plants, animal or
fungus kingdom
ECOLOGICAL IMPORTANCE OF PROTISTS
• Autotrophic Protists – photosynthetic protists at the
base of the food chain makes much of the diversity of
aquatic life possible
• EX/ Algae
• Heterotrophic Protists – some heterotrophic protists
engulf and digest their food, while others live by
absorbing molecules from the environment.
• EX/ Paramecium, amoeba
• Symbiotic Protists
• Mutualistic – algae help health of coral reefs,
Trichonympha live in guts of termites, helping them
to digest cellulose
• Parasitic – can cause intestinal disease, African
Sleeping Sickness, & Malaria
Red blood cell
FUNGI
• Heterotrophic – feed on dead or decaying
organic matter (absorb)
• Secrete digestive enzymes into their food
source, then absorb nutrients though their
cell walls
• Cell walls made of chitin
• Unicellular (yeasts) or Multicellular
(mushrooms)
ECOLOGICAL IMPORTANCE OF FUNGI
• Decomposers – many species of fungi help ecosystems
maintain homeostasis by breaking down dead organisms
and recycling essential elements and nutrients.
• Parasites – parasitic fungi can cause serious diseases
in plants and animals
• EX/smuts and rusts in plants
• Athlete’s foot & ringworm
• Symbiotic Fungi:
• Lichens – mutualistic association between a fungus
and a photosynthetic partner (algae or
cyanobacteria). Are often the first organisms to
enter barren environments and help in early stages of
soil formation.
• Michorrhizae – mutualistic association between a
fungus and a plant root. Estimates that 80-90% of all
plant species have this sort of relationship. Fungus
collects water and minerals, bringing them to the
root, plant supplies the fungi with the products of
photosynthesis (sugars).
PLANTS
• Multicellular
• Cell walls with cellulose
• Autotrophic
• Have chloroplasts
ANIMALS
• Multicellular
• Heterotrophic
• No cell walls
• Most can move