Good Morning Honors!

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Good Morning Honors!

• Get ready to do the flip part of the labwe
  need to get this started at 1155 sharp. Make
  sure your group KNOWS what is going on. I will be
  making ONE announcement, at the start of the
  time. Groups without a time will be the
  evaluators and get to check the groups when you
  move two tables. ?

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Good Morning!

• Please log Coloring Plate 1
• Due tomorrow coloring plate 2 and 17-1 to 17-2
  reading (notes or questions)
• Get ready for some NOTES today ?
• Lab tomorrow, notes Wednesday, notes Friday (FYI)

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Eras of Life

• Investigating the geologic time scale

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Precambrian

• Life arose in the Precambrian era
• 87 of the entire geologic time scale
• Early bacteria probably resembled chemosynthetic
  bacteria that live today
• 3.8 BYA, the first chemical fingerprints of
  complex cells occur
• Microfossilssingle-celled prokaryotic fossils
• 3.46 BYA, photosynthetic bacteria occur

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Origin of Free O2

• Prokaryotes evolved without oxygen
• Cyanobacteria evolved with photosynthesis
• Atmosphere filled with free O2
• Accumulation of poison O2 was the first selection
  pressure
• Demise of anaerobic organisms and rise of aerobic
  organisms

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A better atmosphere

• O2 forms ozone, or O3 in the upper atmosphere
• Ozone shield blocks Ultraviolet radiation from
  the sun that would otherwise break down organic
  compounds

• Allowed organisms the option to live on land,
  unshielded by the water

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Eukaryotic Cells Arise

• Eukaryotic cell
• Always aerobic
• Has a nucleus
• Has organelles
• Arose 2.1 BYA

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The Endosymbiotic Hypothesis ?

1. Mitochondria were once free-living, aerobic,
   prokaryotes (crossovers)
2. Chloroplasts were also free-living, but were
   aerobic photosynthetic prokaryotes
3. A nucleated cell probably englufed these
4. Became organelles (mutualistic relationship)
5. Cillia and flagella may have originated from
   slender, undulating prokaryotes

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Data Supporting this theory

1. Mitocondria and chloroplasts have their OWN DNA.
2. The DNA is similar to bacteria
3. They also have their own ribosomes
4. The ribosomes are like bacteria
5. Both reproduce by binary fission!

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Evolution of Sexual reproductionHow did sexual
reproduction speed up the evolutionary process?

• Prokaryotes?asexual reproduction?less genetic
  variation? no super advantageous traits? very
  little natural selection!

• Eukaryotes?sexual reproduction?shuffled up
  genes?advantageous traits? natural and sexual
  selection!

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Multicellularity Arises

• It is not really known when they appeared
• The first multicellular organisms would have been
  microscopic
• Fossils-Ediacara hills of south Australia
• 600-545 MYA
• Soft-bodied, early invertebrates
• Mudflats in shallow marine water
• Lacked internal organs
• Absorbed nutrients from the sea

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Paleozoic Era

• Lasted over 300 million years
• Very active period
• 3 major extinctions
• total disappearance of a species or taxonomic
  group
• Mass extinction large number in a short amount
  of time (a few million years)

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Periods in the Paleozoic Era

• Cambrian
• Devonian

• Ordovician/Silurian
• Carboniferous

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The Cambrian period

• Invertebrates without a vertebral column
• Todays invertebrates ancestors
• Fossils are easy to find in the Cambrian, but not
  before (do you know why?)
• Cambrian seafloors dominated by trilobites
• Evolution of exoskeletons
• Evolution of skeletons due to selection pressures

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Organisms of the Cambrian period

• Trilobites, jellyfish, worms, sponges, brachiopods

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Ordovician Period/Silurian

• Marine algae expanded to fresh water
• Vascular plants invaded land
• Spiders, centipedes, mites and millipedes
  preceded insects
• Early vertebral columns evolved

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Organisms of the Ordovician

• Ancestors of octupi/squid, aquatic arthropods,
  jawless fish, insects, simple plants

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Devonian Period

• Age of the FISHES
• Common organisms ferns, fish with
  jaws/bones/scales, cartilaginous fishes (sharks),
  first amphibians

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Carboniferous period

• Coal forming forests
• Common organisms club moss, horsetails, giant
  ferns, reptiles/amphibians, winged insects
• Age of the amphibians
• Early plants and amphibians were larger and more
  abundant
• Permian mass extinction-95 complex life

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Part 2 Mesozoic and Cenozoic
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Mesozoic Era

• After the Permian extinction
• Lasted 180 million years
• The era that included dinosaurs and flowering
  plants (plants as we know them)
• Three periods-
• Triassic
• Jurassic
• Cretaceous

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Triassic Period

• Common organisms fishes, insects, reptiles,
  cone-bearing plants

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Triassic Period

• Age of the reptiles
• Gymnosperms flourished
• Age of the cycads
• Reptiles underwent adaptive radiation
• Small mammals arose

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Good Friday Morning!Please turn in your
radiometric dating lab Log Coloring Plate 3
for stampingHONORS APPLICATIONS?People going
to regionals-Dont leave today without your sci
fair binder (get it now ?)
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Therapsids, reptiles with mammal-like features
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Coelophysis- Carnivore with hollow bones and two
legs
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Jurassic Period- Common Dinosaurs for 150
million years!

• Dicraeosaurus-very large
• Archaeopteryx- first birds

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Cretaceous Period

• Common Dinosaurs (T. rex), reptiles, leafy
  trees, shrubs
• New Chinese fossil, Jeholodens, reveals early
  mammal with long snout and sprawling reptile-like
  hind limbs.
• Mass extinction at the end of this Era

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The Cenozoic Era

• Divided into Tertiary and Quaternary periods
• Mammals with hair and mammary glands speciate

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Tertiary Period

• Common animals marine mammals (whales/dolphins),
  flowering plants, insects, grasses, grazing
  animals

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Quaternary Period

• The worlds climate cooled over the last 2 epochs
• Pleistocene Epoch
• Many large sloths, beavers, wolves, bison, woolly
  rhinoceroses, mastodons, mammoths

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Mammalian Diversification

• Paleocene Epoch
• Mammals were small and resembled rats
• Eocene Epoch
• All of the modern orders of mammals had developed
• Oligocene Epoch
• Many herbivores and carnivores-extinct today

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Evolution of the Primate family

• 20,000 YAG, warming of the Earth, melting of the
  glaciers
• Common algae, coral, mollusks, fish, mammals,
  insects, birds, mammoths
• First primates were squirrel-like mammals
• Apes diversified during the Miocene and Pliocene
  epochs-includes first hominids

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Factors that influence Evolution

• Patterns

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What are the patterns of evolution?

1. Continental Drift
2. Plate Tectonics
3. Mass Extinctions

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Continental Drift

• The Earths crust is dynamic, not immobile
• 1920- Alfred Wegener presents idea of continental
  drift

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Pangaea

• During the Permian period, the continents were
  joined to form one super continent
• Later, it divided into Gondwanaland and Laurasia
• Then split to form todays configuration
• Confirmed in the 1960s

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Explains why

• Continents look like they could have fit
  together at one point
• Similar geological structures (e.g. mountain
  ranges) are found in areas where continents used
  to touch

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Unique distribution patterns of species (e.g.
species of seed fern Glossopteris)
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Fossils found on different continents
(Cynognathus and Lystrosaurus)
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Australia, S. America, and Africa have
distinctive mammals

• Current mammalian diversity is the result of
  isolated evolution, post-founder species

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Plate Tectonics

• The study of the behavior of Earths crust
• Moving plates are formed at ocean ridges
• Destroyed at subduction zones
• Seafloor is spreading is the lateral movement of
  oceanic crust away from ocean ridges due to
  material being added

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Ocean Ridges

• Ridges on ocean floors where oceanic crust forms
• Molten rock rises and adds material

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Subduction Zones

• Regions where oceanic crust collides with
  continental crust
• Oceanic crust descends into the mantle where it
  is re-melted

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Ocean Trenches

• Where the ocean floor is at the leading edge of a
  plate
• Deep trench forms bordered by volcanoes or
  volcanic island chains

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Mountain Ranges

• Two continents collide forming a mountain range
• Himalayasresult of the collision of India and
  Eurasia
• Transform boundaries
• Regions where two crustal plates meet and scrape?
  Earthquakes!

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Mass Extinctions

• Five mass extinctions total at the end of
• Ordovician
• Devonian
• Permian
• Triassic
• Cretaceous
• Attributed to tectonic, oceanic, and climactic
  changes in our Earth

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The Cretaceous Extinction

• Walter and Louis Alvarez
• Extinction due to a bolide
• An asteroid that explodes producing meteorites
• Supporting data-
• Layer of iridium in Cretaceous clay
• Huge crater near the Yucatan
• Worldwide atomic explosion

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David Raup and John Sepkoski

• Proposed that marine fossils show mass
  extinctions every 26 million years
• This is in periocidy with astronomical movement
  through the galaxy

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Ordovician Extinction

• Attributed to continental drift
• Gondwanaland at the south pole
• Glaciers chilled the oceans and land until the
  glaciers drifted away from the pole

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Permian Extinction

• Very severe extinction
• 90 of ocean species and 70 of land species
  extinct
• Perhaps due to
• Excess carbon dioxide
• Due to a change in ocean circulation
• Due to a lack of polar ice caps

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Triassic Extinction

• Meteorite collision with Earth
• Crater in central Quebec? impact site?