Evolution

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Evolution
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• I. Evolution __________
• A. New species evolve from pre-existing species
• B. Explains
• 1. Diversity of life
• 2. __________ between living organisms
• II. History of Life How we know
• A. ________-remaining traces of a once living
  organism
  
• 1. Fossil record- info about age and kinds of
  organisms
  
• a. ___________ rock
• b. Oldest layers at the bottom (typically)

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• B. Radioactive Dating- tells us when organisms
  lived
  
• 1. ________- isotope of carbon (extra neutrons)
  which decays into C12 over time.
  
• 2. _______- the length of time it takes for ½
  the mass of an element to decay
  
• 3. C14 takes 5700 years for half to become
  C12
  
• 4. Only accurate to 60,000 years
• 5. Earth-4.5 billion years old (half life of
  ____________ which decays to thorium)
  

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• C. Fossil record has revealed times of
  _____________ followed by rise in new species.
  
• 1. Caused by drastic changes in environment
• Example - Extinction of dinosaurs allowed the
  rise of mammal NOVA clip
  
• D. _______________
• Fossils show that new organisms arise in areas
  where similar forms already lived
  
• Example - Marsupials
• Others ___________________

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• III. Adaptation- a trait that allows a species
  to better survive in its environment. Cartoon
  
• A. _______________ Adaptations structural
• 1. anteater- long, sticky tongue
• 2. Hollow bones of birds
• 3. Stinging cells on jellyfish
• B. Physiological Adaptations ___________
• 1. Fireflies (light up)
• 2. Scent of skunks
• C. _____________ Adaptations
• 1. Courtship displays (peacock)
• 2. Rhythm of lights in firefly (females attract
  males)

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(No Transcript)
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• What Kind of Adaptation?
• Woodpecker Finches
• Monarch and viceroy butterflies
• Smell of roses
• Eagles pushing sibling out of nest
• Quills on a porcupine
• Building a nest
• Walking stick looks like a twig
• Flower that smells like rotten meat
• Spots of a fawn
• Turtle pulling in its head

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Take notes on the various plants and animals of
the Seychelles islands. Note adaptations and
what type each one is. After watching the video,
write a paragraph describing 3 plants or animal
adaptations you saw. For each, tell what kind of
adaptation it is morphological, behavioral, or
physiological
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• IV. Theories of Evolution
• Jean Baptiste LaMarck (1744-1829)
• Hypothesis - Inheritance of _____________ (also
  Use and disuse)
  
• acquired trait- changes after birth
• Thought that traits could be passed to offspring
• Structures used more- develop more
• Giraffes long necks- stretched to reach leaves
• Eventually rejected by Mendels research,
  although much later
  
• Modern genetics - Phenotypic changes dont change
  genotype ?no way to change genetic info in sex
  cells for inheritance other than mutation
  
• LaMarck is first to state
• organisms change over time
• new types of organisms come from older types

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B. Charles Darwin 1. 5 years traveling th
e world HMS Beagle (mapping earth g
athering specimens) 2. Notes on living sp
ecies, fossils, and geologic processes
3. ____________ Islands (be able to
compare and contrast to Seychelles)
a) islands near Ecuador b) plants and animals r
elated to, but different from mainland.
c) famous discovery- 13 species of ___________
-Descended from single/few birds from mainland
- different types of beaks (genetic variation)
- ate different foods -adapted to type of foo
d d) species must change - to survive changi
ng habitats - many differences in millions of y
ears
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• Darwins Theory
• Evolution by Natural Selection
• (Book On the Origin of Species by Means of
  Natural Selection)
  
• All organisms descended from common ancestors
  that lived a long time ago.
  
• Environment limits growth of populations (food
  supply, war, disease)

• Changes in Species by Natural Selection
• overproduction- in good conditions populations
  increase until resources (food) become scarce.
  
• Competition-
• Between Species (wolves vs. coyotes for deer)
• Within Species (bluegill vs. bluegill for
  insects)
  

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• 3. Survival of the _________- best adapted to the
  environment survive (adaptive advantage)
  
• Reproduction- those that survive pass on traits
• Examples
• Daphnia magna
• Galapagos finches

• Speciation and Isolation
  - species that are divided by geography may
  evolve into separate species. (over time, some
  traits are passed on, others not) (Ostrich and
  rhea.)
• Darwin and Mendel lived at the same time. No
  one took Mendels work seriously -- it was not
  studied until 40 years after he did his
  experiments
• Watch Video on Galapagos Islands

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• V. Evidence of Evolution
• Homologous Structures
• Similar structure on different species
• Function somewhat similar ?very different
• Example pentadactyl limbs
• Similar structures suggest a common ancestor
• What can be more curious than that the hand of a
  man, formed for grasping, that of a mole for
  digging, the leg of a horse, the paddle of a
  porpoise, and the wing of a bat should all be
  constructed on the same pattern and should
  include the same bones in the same relative
  positions?
• Charles Darwin in On the Origin of Species

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Pentadactyl (5-digit) Limbs
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• Nearly all vertebrates have a pentadactyl limb
• Structure is similar in all, despite different
  uses for the limb

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• B. _____________ Structures (analogous means
  parallel)
  
• 1. Similar function, different structure
• (example wings on bats and butterflies)
• 2. Does not show a relationship
• C. ___________Structures
• 1. Apparently functionless structures
• that used to serve a function
• 2. Like structures in other organisms that
  DO function

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• D. Similarities in Embryos
• 1. _________ (becomes backbone) in all
  vertebrates
  
• 2. Gills (yes, you had vestigial gills!)
• Similarities in DNA
• 1. Same _________bases in all living things
  (A,T,G,C)
  
• A comparison of a similar protein between more
  closely related species reveals fewer differences
  in amino acid sequence, while distantly related
  species proteins have more variation (human
  genome project)
• Scientists can predict when 1 species split into
  2 (common ancestry)

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Comparison of vertebrate embryos
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ß hemoglobin comparison
The number of changes is the number of
differences in the amino acid sequence of the
protein between the divergent groups.
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If we have a common ancestor with chimpanzees,
then why do we have different numbers of
chromosomes (46) than the great apes (48)?

• Chapter 6 from NOVA Intelligent design on
  trial.
  
• Extra credit opportunity watch the video
  hyperlinked above. Earn 1 pt extra credit for
  each chapter by writing a half page or more
  summary.

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• Patterns of Evolution
• _______________
• 2 species are changing at the same time together
• Examples
• predator and prey
• Plants and animals that pollinate them
• ________________
• Species from different ancestors become more
  alike
  
• Example
• Shark (fish) and dolphin (mammal) (mammals first
  appeared on land)

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• ____________ Evolution
• New species- less and less like the one it
  evolved from
  
• Examples
• Horse, donkey, zebraall from pliohippus
• _________ radiation- many species evolved from
  one species
  
• Galapagos finches- diverged because of
  availability of food.
  
• Artificial selection- man speeds up divergence
• much more than would have happened in nature
• dogs Canis familiaris (German shepherd, poodle)

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• d) 3 Great Periods of adaptive radiation
• i. Rise of marine (ocean) animals (many
  habitats, little competition
  
• ii. Rise of ___________ Plants (followed
  evolution of insects and birds)
  
• iii. Rise of __________
• Extinction of dinosaurs
• Mammals able to grow larger and survive.

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Natural Selection and Genes
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A. Selection works on the ___________ of
organism 1. Helpful traits must appear to be s
elected a) beak types in finches b) fan disp
lay by peacock 2. Harmful traits (genes) may die
out slowly a) If dominant, tend to be lost
b) Recessive traits hidden by dominant ones
3. ________ allows populations of species to
adapt. If all individuals have same genes, env
ironmental change may cause species to become e
xtinct
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• B. Rate of Evolution
• ______________
• a) Darwin- Slow Steady (hard to see)
• b) Problem Fossil record shows some gaps,
  however, slowly closing as new fossils are
  uncovered
  
• _____________ Equilibrium
• Quick Changes (over 1000s of years)
• Changes separated by long periods of no change
  (may explain some gaps in fossil record.)
  

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3. Current Knowledge/Issues
a) Mutations cause quick changes
i. Viruses and bacteria evolve very
rapidly. (we cant find new antibiotics fast
enough) ii. Genetic Engineering-what effect?
b) Extinction- Loss of species i. many
endangered species lost each year--
rainforests ii. Endangered species. Name some?
?