Transcript Introduction to Zoology & Classification

Introduction to Zoology &
Classification
SCIENTIFIC WORDS / IDEAS
Scientific Terminology
• Hypothesis: A prediction of the outcome
of an experiment
• Written: If______________, then
_____________, because____________.
Testing Hypotheses
• Observation
– Something you take in with your senses
• Experiment
– Perform CONTROLLED experiments to test
repeated observations
– If continued to be accepted………….
Scientific Theory
•
•
•
•
•
Principle
Tested many times
Explains many different phenomena
Makes predictions
Falsifiable – people are constantly trying to
prove wrong and correct “bad”’ science
Theory vrs Scientific Theory
• Theory (as used outside of science)
– Guess
– Speculation
– Has not been tested
Law vrs Theory
• Law
– Observation that has been repeated
numerous times
– Law of gravity
– Does not explain the observation
• Theory
– Explains why or how something in nature
happens
Which is most important to a
scientist?
1.
2.
3.
4.
Fact
Hypothesis
Law
Theory
Theory is the most important
• Theory
– Explains laws,
hypotheses and facts
• Law
– States what happens
• Hypothesis
– Untested theory
• Fact
– Observation
Major Scientific Theories
• Germ Theory of Disease
– Germs cause infectious disease
• Atomic Theory
– Matter is made if tiny atoms
• Gene Theory (Chromosomal Theory)
– Genes on chromosomes determine heredity
• Cell Theory
– All living things are made of cells
Theory of Evolution
• Populations of
organisms change
over time
• Changes result in
new species that
share a common
ancestor.
Evolution is both a fact and a
theory
• Fact
– Evolution is
documented in the
fossil record and has
been observed in our
lifetime.
• Theory
– How evolution
happens
Theory of Evolution
• Scientists no longer
ask if evolution
occurs. They study
how evolution occurs.
• Evolution is the major
theory that guides
research in Zoology
CLASSIFICATION REVIEW
Aristotle 384 BC
• Classified organisms
as either plants or
animals
Carolus Linnaeus 1707-1778
• Swedish Botanist
• Systema Naturae, 10ed
– 1758
• Classification system
• Taxonomic groups of
related organisms
• Binomial nomenclature
– two names
– Genus + species
– Capitalized, Italics
Taxonomic Groups
Species
• “Species are groups
of actually or
potentially
interbreeding
populations, which
are reproductively
isolated from other
such groups.”
• When they reproduce,
create FERTILE
offspring
Ernst Mayr
*
* Archaea
Classification of Living Things
DOMAIN
Bacteria
Archaea
KINGDOM
Eubacteria
Archaebacteria
Protista
Fungi
Plantae
Animalia
CELL TYPE
Prokaryote
Prokaryote
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Cell walls with
peptidogly
can
Cell walls without
peptidoglyca
n
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Cell walls of
cellulose
;
chloropl
asts
No cell walls
or
chloropl
asts
Unicellular
Unicellular
Most unicellular;
some
colonial;
some
multicellular
Most
multicell
ular;
some
unicellul
ar
Multicellular
Multicellular
Autotroph
Heterotroph
CELL
STRUCT
URES
NUMBER OF
CELLS
MODE OF
NUTRITI
ON
EXAMPLES
Eukarya
Autotroph or
heterotrop
h
Autotroph or
heterotroph
Autotroph or
heterotroph
Heterotroph
Streptococcus,
Escherichi
a coli
Methanogens,
halophiles
Amoeba,
Paramecium
, slime
molds, giant
kelp
Mushrooms,
yeasts
Mosses,
ferns,
flowerin
g plants
Sponges,
worms,
insects,
fishes,
mammal
s
Kingdom Monera or Eubacteria
•
•
•
•
Single celled
Prokaryotic
Make or absorb food
Cell wall
– peptidoglycan
Kingdom Archaea
•
•
•
•
Single celled
Prokaryotic
Make or absorb food
DNA
– Similar to Eukaryotic
• Cell wall
– Pseudopeptidoglycan
or protein only
Kingdom Protista
• Single celled
• Eukaryotic
• Ingest or produce
food
• Kind of the “junk
drawer” of
classification
Kingdom Fungi
• Multicellular
• Eukaryotic
• Cell wall
– Chitin
• Absorb food
Kingdom Plantae
• Multicellular
• Eukaryotic
• Cell wall
– Cellulose
• Produce food
– photosynthesis
Kingdom Animalia
•
•
•
•
•
Multicellular
Eukaryotic
No cell wall
Ingest food
Motile
Terminology
• Classification
– Assigning organisms to
different catagories based
on their relationship
• Taxonomy
– The science of naming
organisms
• Systematics
– Determining evolutionary
relationships of organisms
Cladogram
• Evolutionary relationship
of a group of organisms
• Each clad (group) share
something in common
• Ancestral traits are the
oldest
• Derived traits evolved
later
• Nested hierarchially
Cladogram for Transportation
• Wheels are the most
ancestral
• Wings are the most
derived
MAKE A CLADOGRAM
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
Gorilla
Chimpanzee
Tiger
Lizard
Fish
Tail Lost
Fur
Four Limbs
Synapomorphy
• A derived character shared by two or more
groups.
– Fur is a synapomorphy for the various groups
of mammals.
– Synapomorphies are used to determine
evolutionary relationships
Symplesiomorphy
• Character shared by a number of groups
• Inherited from ancestors older than the
last common ancestor.
– Symplesiomorphies are not helpful in
determining evolutionary relationships
Accepted Cladogram for Animals
Birds
Mammals
Reptile
Feathers
Amphibian
Fish
Fur
Endothermic
Amniotic Egg
Four Limbs
Vertebrae
Homologous Characters
• Similarity in
features of
different groups
because of their
descent from a
common
ancestor
Analagous Characters
• Similarity in
characteristics in
different groups
caused by
factors OTHER
THAN their
distant common
ancestry
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
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
Polyphyletic
• A group that has
some similarities
• Common ancestor is
in not in the group
• Not all descendants
are included
• Example: Flying
vertebrates
Asymmetry
•No Lines of symmetry
•Most protists & many
sponges
•Do not develop complex
communication, sensory or
locomotor function
Radial Symmetry
•Multiple lines of
symmetry
•Not as simple
communication,
sensory or
locomotor
function; but still
not as complex
Bilateral Symmetry
•One line of symmetry
•Usually longitudinal, dividing
animals into right and left
mirror images
•Characteristic of active,
motile, crawling or swimming
animals
•Usually move in one direction
– so the end that faces the
world is normally where
complex sensory, nervous and
feeding structures evolve and
develop. (Cephalization)