Origin of Life

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• Origin of Life

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History of Life on Earth
History of the World https//www.youtube.com/watch
?vm1R8-E71wAc

• The origin of life, 4.6 billion years ago.
• The Universe came into being about 15 billion
  years ago.
• Big Bang Theory The sudden appearance of all the
  matter and energy in the Universe as a single
  very hot and dense point.

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Formation of Organic Molecules

• Fairly complex organic molecules will form
  spontaneously under conditions that existed on
  the primitive Earth.
• Results in a primordial soup
• Oceans filled with a dilute solution of organic
  molecules of all kinds.

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Age of the Bacteria

• Prokaryotes dominated the Earth for most of its
  history.
• Prokaryotic fossils are very small, and consist
  mainly of fossilized cell walls.
• Traces of organic compounds can also be found.
• Bacteria can live under a much wider variety of
  conditions than eukaryotes.
• They use many different sources of energy and
  carbon, and they can grew at very high
  temperatures, high pressures, acidic conditions.
• They were called Archaebacteria.

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The Onset of Oxygen

• The atmosphere of the primitive Earth was
  probably like that of Mars today nitrogen,
  carbon dioxide, water vapor, but no free oxygen.
• Cyanobacteria is credited with creating the
  oxygen in the atmosphere.
• About 2 billion years ago, the oxygen level in
  the atmosphere started to rise.

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Rise of the Eukaryotes

• Endosymbiont hypothesis mitochondria were once
  free-living bacteria that developed an
  intracellular symbiosis with a primitive
  eukaryote.
• Today all eukaryotes have mitochondria.
• Chloroplasts another endosymbiont, of a
  cyanobacteria. Found in plants and algae.

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Early scientists proposed ideas about evolution.

• Evolution is the process of biological change by
  which descendants come to differ from their
  ancestors.

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HISTORY OF LIFE IN ONE YEAR

• https//www.youtube.com/watch?v5uodfwAgzTQ

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Self Check

• Which of the following is a term for a group of
  similar organisms that can reproduce and produce
  fertile offspring?
• a. individual
• b. population
• c. species
• d. fossil

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Ch 12.1
Evidence of common ancestry(Evolution Theory)
among species comes from many sources.

• Indirect Evidence
• Fossil Record
• Geography
• Comparative Anatomy
• Comparative Embryology
• Comparative Biochemistry
• Direct Evidence
• Current observations

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Evidence for evolution in Darwins time came from
several sources.

• Fossils provide evidence of evolution.

• Fossils in older layers are more primitive than
  those in the upper layers.

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Theories of geologic change set the stage for
Darwins theory.

• There were three theories of geologic change.
• catastrophism

• gradualism

• uniformitarianism

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• Uniformitarianism is the prevailing theory of
  geologic change.

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Law of Superposition

• In which rock layer would you find the oldest
  fossils and why?

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• The study of geography provides evidence of
  evolution.

• island species most closely resemble nearest
  mainland species
• populations can show variation from one island to
  another

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• Embryology provides evidence of evolution.

• identical larvae, different adult body forms
• similar embryos, diverse organisms

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Poll

• Which of these embryos is that of a human?
• A B C D

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(No Transcript)
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Self-Check

• 1. Biogeography is the study of the
• a. distribution of organisms around the world.
• b. environments around the world.
• c. different types of rocks around the world.
• d. age of fossils around the world.

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Self-Check

• 2. What is suggested by the similarity of early
  embryos of different species of vertebrates?
• a. no evolutionary relationship between the
  groups
• b. recent common ancestry
• c. similar environments in the past
• d. evolution from a distant common ancestor

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• The study of anatomy provides evidence of
  evolution.

• Homologous structures are similar in structure
  but different in function.
• Homologous structures are evidence of a common
  ancestor.

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• The study of anatomy provides evidence of
  evolution.

• Analogous structures have a similar function.

• Analogous structures are not evidence of a common
  ancestor.

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Analyze

• Using the terms homologous and analogous,
  identify which group of structures provides
  evidence for a common ancestor. Explain.

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Structural patterns are clues to the history of a
species.

• Vestigial structures are remnants of organs or
  structures that had a function in an early
  ancestor.
• Ostrich wings are examples of vestigial
  structures.

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Self-Check

• 3. Some organisms that share a common ancestor
  have features that have different functions, but
  similar structures. These are known as
• a. vestigial structures.
• b. analogous structures.
• c. homologous structures.
• d. fossil structures.

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Self-Check

• 4. If an organism has a vestigial structure, that
  structure likely once had a function in a(n)
• a. close relative.
• b. early ancestor.
• c. unrelated organism.
• d. embryological stage.

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Self-Check

• 5. Which of the following is an example of a
  vestigial structure?
• a. the wings of red-tailed hawks
• b. the hind limbs of a house cat
• c. the fins of a shark
• d. the wings of an ostrich

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Comparative Biochemistry

• All living things contain similar biochemical
  compounds
• Examples would include structure and function of
  DNA, RNA, and proteins (including enzymes) are
  similar in all organisms
• IF AVAILABLE THE BEST EVIDENCE TO USE WHEN
  COMPARING ANCESTORY

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KEY CONCEPT Darwins voyage provided insight on
evolution.
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Charles Darwin and the HMS Beagle
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Darwin observed differences among island species.

• Variation is a difference in a physical trait.
• Galápagos tortoises that live in areas with tall
  plants have long necks and legs.
• Galápagos finches that live in areas with
  hard-shelled nuts have strong beaks.

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• An adaptation is a feature that allows an
  organism to better survive in its environment.

• Species are able to adapt to their environment.
• Adaptations can lead to genetic change in a
  population.

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• Variation
• Adaptation

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Darwin observed fossil and geologic evidence
supporting an ancient Earth.

• Darwin found fossils of extinct animals that
  resemble modern animals.
• Darwin found fossil shells high up in the Andes
  mountains.

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• He saw land move from underwater to above sea
  level due to an earthquake.

• Darwin extended his observations to the evolution
  of organisms.

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• Fossils

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Self Check

• The difference in the physical traits of an
  individual from those of other individuals in a
  group is called a(n)
• a. change.
• b. adaptation.
• c. species.
• d. variation.

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• Over time, adaptations can lead populations to
  experience
• a. environmental changes.
• b. genetic changes.
• c. geologic changes.
• d. extinctions.

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• What did Charles Darwin observe in finch
  populations on the Galápagos Islands off the
  coast of South America?
• a. different species on different islands
• b. all species on one of the islands
• c. identical species on all the islands
• d. the same species as in North America

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• What did Charles Darwin learn from the fossils of
  a giant armadillo that he found in Argentina?
• An earthquake led to the armadillos extinction.
• Armadillos used to be marine organisms.
• Modern animals may be related to fossilized
  organisms.
• Fossils do not resemble modern animals.

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• Fossils of marine organisms high in the Andes
  Mountains led Darwin to conclude that
• a. Earth is 6000 years old.
• b. interspecific variation had taken place.
• c. great change can happen over time.
• d. an earthquake had taken place.