Introduction to Zoology; EVOLUTION

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Introduction to Zoology EVOLUTION
Classification REVIEW
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SCIENTIFIC TERMINOLOGY
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Scientific Terminology

• Hypothesis A prediction of the outcome of an
  experiment
• Written If______________, then _____________,
  because____________.

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Testing Hypotheses

• Observation
• Something you take in with your senses
• Experiment
• Perform CONTROLLED experiments to test repeated
  observations
• Controlled means youre changing one variable
  at a time
• If continued to be accepted.

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Scientific Theory

• Principle
• Tested many times
• Explains many different phenomena
• Makes predictions
• Falsifiable people are constantly trying to
  prove wrong and correct bad science

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Theory vs Scientific Theory

• Theory (as used outside of science)
• Guess
• Speculation
• Has not been tested

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Law vs Theory

• Law
• Observation that has been repeated numerous times
• Law of gravity
• Does not explain the observation
• The what
• Theory
• Explains why or how something in nature happens
• The why or how

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Which is most important to a scientist?

• Fact
• Hypothesis
• Law
• Theory

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Theory is the most important

• Theory
• Explains laws, hypotheses and facts
• Law
• States what happens
• Hypothesis
• Untested theory
• Fact
• Observation

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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

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THE THEORY OF EVOLUTION THROUGH NATURAL SELCTION
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Theory of Evolution

• Populations of organisms change over time
• Changes result in new species that share a common
  ancestor.

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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

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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

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Evolution ? lots of misconceptions

• Change over time
• Not a straight line
• No direction to change ? not getting better
  each time
• Things in a population change at different rates,
  at different times in different ways
• Therefore, not every organism in a population
  changes or evolves

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Evolution Acts Upon

• Variation
• Members of a population vary from one another
• WHY?
• Asexual Reproduction
• Mutations
• No partner needed
• Sexual Reproduction
• Recombination each
• generation
• Mutations
• Partner needed

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Struggle for Life

• Organisms regularly compete to obtain food, space
  other necessities for life also to avoid
  predators
• There is an OVERPRODUCTION of organisms ? high
  birth rates lower death rates
• Shortage of needs (limited resources) force
  COMPETITION

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Fitness

• A key factor in the struggle for life is how well
  suited an organism is to its environment
• Fitness is a measure of an organisms ability to
  survive and reproduce
• This is a result of
• adaptations

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Adaptations

• Inherited characteristics that increase an
  organisms chance of survival
• Can be anatomical/structural, behavioral
  physiological

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Adaptations

• Successful adaptations lead to organisms being
  MORE suited to the environment, which allows for
  a better fitness, which creates a larger
  percentage of their DNA being passed on ? BETTER
  CHANCES AT SURVIVAL!
• Generation after generation individuals continue
  to compete each with its advantages
  disadvantages

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Survival of the Fittest

• Over time this competition allows certain
  adaptations to prosper over other adaptations
• This leads to the survival of the fittest ?
  individuals that are better suited (adaptations
  that enable fitness) survive reproduce most
  successfully
• NATURAL SELECTION

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Natural Selection

• This is the THEORY, evolution is a fact
  (observable)
• Without human control or direction
• Results in changes in a population over MANY
  generations
• Over LONG periods of time
• Produces organisms with different structures,
  occupying different niches occupying different
  habitats

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Descent with Modification

• aka change over time
• Through natural selection, each living species
  has descended with changes from other species
  over a long period of time
• Implies that all living organisms are related and
  that there is a common ancestor
• Tree of life links all things together

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SUMMARY

• There is a natural variation in a population.
  When this variation provides differences in
  adaptations that effect fitness, those organisms
  with adaptations that are favored will be able to
  reproduce more. When this occurs over many
  generations change can be seen in the species.

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CLASSIFICATION
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Aristotle 384 BC

• Classified organisms as either plants or animals

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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

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Taxonomic Groups
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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
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Archaea
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Classification of Living Things Classification of Living Things Classification of Living Things Classification of Living Things Classification of Living Things Classification of Living Things Classification of Living Things
DOMAIN Bacteria Archaea Eukarya Eukarya Eukarya Eukarya
KINGDOM Eubacteria Archaebacteria Protista Fungi Plantae Animalia
CELL TYPE Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
CELL STRUCTURES Cell walls with peptidoglycan Cell walls without peptidoglycan Cell walls of cellulose in some some have chloroplasts Cell walls of chitin Cell walls of cellulose chloroplasts No cell walls or chloroplasts
NUMBER OF CELLS Unicellular Unicellular Most unicellular some colonial some multicellular Most multicellular some unicellular Multicellular Multicellular
MODE OF NUTRITION Autotroph or heterotroph Autotroph or heterotroph Autotroph or heterotroph Heterotroph Autotroph Heterotroph
EXAMPLES Streptococcus, Escherichia coli Methanogens, halophiles Amoeba, Paramecium, slime molds, giant kelp Mushrooms, yeasts Mosses, ferns, flowering plants Sponges, worms, insects, fishes, mammals
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Kingdom Monera or Eubacteria

• Single celled
• Prokaryotic
• Make or absorb food
• Cell wall
• peptidoglycan

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Kingdom Archaea

• Single celled
• Prokaryotic
• Make or absorb food
• DNA
• Similar to Eukaryotic
• Cell wall
• Pseudopeptidoglycan
• or protein only

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Kingdom Protista

• Single celled
• Eukaryotic
• Ingest or produce food
• Kind of the junk drawer of classification

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Kingdom Fungi

• Multicellular
• Eukaryotic
• Cell wall
• Chitin
• Absorb food

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Kingdom Plantae

• Multicellular
• Eukaryotic
• Cell wall
• Cellulose
• Produce food
• photosynthesis

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Kingdom Animalia

• Multicellular
• Eukaryotic
• No cell wall
• Ingest food
• Motile

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Terminology

• Classification
• Assigning organisms to different categories
  (taxa) based on their relationship
• Taxonomy
• The science of naming organisms
• Systematics
• Determining evolutionary relationships of
  organisms

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CLADOGRAMs / PHYLOGENIC TREES
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Evolutionary Tree / 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

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Cladogram for Transportation

• Wheels are the most ancestral
• Wings are the most derived

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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

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Tiger
Lizard
Fish
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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

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Automorphy

• A character only featured by one taxon
• Example bird feathers

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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

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Accepted Cladogram for Animals
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Homologous Characters

• Similarity in features of different groups
  because of their descent from a common ancestor

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Analagous Characters

• Similarity in characteristics in different groups
  caused by factors OTHER THAN their distant common
  ancestry

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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

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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

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Polyphyletic

• A group that has some similarities
• Common ancestor is in not in the group
• Not all descendants are included
• Example Flying vertebrates