Alexander
Crumpton
Fuqua
 The science involved with the study of a past life.
 The data used for this study of a past life are fossils
 Fossils are the preserved remains or traces of
organisms that have been preserved by geologic
processes.
 Provide evidence of how life and the environment has
changed
 The processes we see today are similar to those in the
past.
 The idea that the same geologic processes shaping the
earth today have been at work throughout history.
 Erosion
 Deposition
 Movement of Lithospheric Plates
 Changes in atmosphere
 The principle that states that all geologic changes
occur suddenly .
 Through catastrophes such as:
 Impact of an asteroid or comet
 Earthquakes
 Mold Fossil
 Cast Fossil
 Petrified (Permineralized) Fossil
 Preserved Fossil
 Carbonized Fossil
 Trace Fossil
 Forms when sediments bury an organism and the
sediments change into rock
 The organism decays leaving a cavity in the shape of
the organism
 Forms when a mold is filled with sand or mud that
hardens into the shape of the organism
 Also known as permineralized fossils
 Forms when minerals soak into the buried remains,
replacing the remains, and changing them into rock
 Forms when entire organisms or parts of organisms are
prevented from decaying by being trapped in rock, ice,
tar, or amber.
 Forms when organisms or parts, like leaves, stems,
flowers, fish, are pressed between layers of soft mud or
clay that hardens squeezing almost all the decaying
organism away leaving the carbon imprint in the rock.
 Forms when the mud or
sand hardens to stone
where a footprint, trail,
droppings, or burrow of
an organism was left
behind
 Helps to give clues to an
animals diet and
lifestyle.
 A record of the major events and the diversity of life
forms in Earth’s history
 At the end of each era, a mass extinction occurred,
many kinds of organisms died out.
 Eon: largest division of time
 Containing two or more Era
 Era: a defined period of time with a start event and an
end event
 Period: form a division which geologist use to divide
earth’s history.
 Epoch: a division of time that is longer than an age,
but shorter than a period
 Precambrian Era
 First era of time
 Bacteria and simple algae, leading to jellyfish and sea worms
 Few fossils
 Paleozoic Era
 Early invertebrates, trilobites, leading to early vertebrate fish,
arachnids, insects, first amphibians, reptiles become
dominant by the end.
 Early land plants, mosses, ferns, cone-bearing plants
 Mesozoic Era
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Reptiles were dominant animals, dinosaurs
Small mammals and birds appeared
Flowering plants and types of mammals increased
Dinosaurs became extinct at the end of this era
 Cenozoic Era
 New mammals appeared
 Diversity of life increased
 Relative age of rocks does not tell exact age
 Can be determined using 2 different methods:
 Ordering of Rock Layers
 Index Fossils
 Ordering of rock layers
 The Law of Superposition
 Each rock layer is older than the one above it.
 Younger layers lie on top of older layers, unless disturbed.
 Index Fossils
 Used to find the relative age
 To be considered an index fossil:
 An organism must have lived for a short period of time in
Earth’s history and must be widespread across the globe.
 Trilobites
 Hard shelled animals
 3 body sections
 Lived in shallow seas
 Became extinct about
245 million years ago.
 Absolute dating is any method of measuring the age of
an event or object in years.
 Radiometric dating
 Radioactive “Parent atoms” decay into “daughter atoms” at a
predictable rate.
 They become trapped in rock when it forms.
 By measuring amount left after decay, scientist can predict
how much time has passed.
 Carbon-14 dating is most frequently used.
 Half-life: the amount of time needed for half of a
radioactive isotope to disappear.
 Other artifacts scientist can use to determine
geological history:
 Ice cores
 Cylinders of ice drilled out of glaciers and polar ice sheets
 Help understand how the climate has changed over time
 Record of atmosphere and compounds in the air where it
formed.
 Examining layers of sedimentary rock
 Makes up about 75% of earths surface
 Forms where sand, mud, or other sediments collect
 Can be disturbed by igneous rock, which is formed from
molten rock (magma), causing intrusions.
 An arrangement of rock layers in which the oldest
rocks are at the bottom.
 Folding: rock layers bend and buckle
 Faulting: a break in the earths crust
 Intrusion: molten rock that squeezes into existing
rock. Always younger than the layer it cuts through.
 Tilting: when internal forces in the earth slant the
layers
 Unconformities: a break in the geologic record created
when rock layers are eroded or when sediment is not
deposited for a long time
 Represent missing time that was not recorded.
 Biological evolution: the change over time of living
organisms
 Acquire characteristics through adaptations
 Change in structure, behavior, or physiology that helps an
organism survive a particular environment
 Homologous Structures: same structure, different function
(wing of a bat and arm of a human)
 Analogous Structures: same function, different structure
(wing of a bird and wing of a butterfly)
 Fossils can be compared to each other and living
organisms to observe any changes over time
 Transitional fossils
 It occurs when an environment changes and the
organism does not have traits necessary to survive and
reproduce.
 Most species that have lived on earth are now extinct.
 Extinction is apparent in the fossil record.
 System used to organize all life on Earth.
 Used to:
 Describe organisms
 Examine the relationships between organisms
 Also referred to as taxonomy (KPCOFGS)
 States that species change over time
 Change in response to their environment
 Charles Darwin is known as the “Father of Evolution”
 Theory that all life is related from a common ancestor
 As genetic mutations occur, the beneficial mutations are
kept and passed on, because they aid in survival
 The process known as natural selection
 The beneficial mutation builds and creates an entirely
different organism.
Charles Darwin
•
Charles Darwin was a naturalist who
sailed around the world from 1831 to 1836
to study biology and geology.
•
With some of the information about
plants and animals he observed on this
trip in mind, he later published a book
about the theory of evolution by natural
selection.
Darwin’s Finches
Here is an example of a Galapagos finch that Darwin researched that adapted
their beaks to eat a type of food source common to the area.
 Phenotype
 Body structure and characteristics
 Can influence the ability to find, obtain, or utilize resources
(Food, water, shelter, etc) and even reproduce
 Genotype
 The genetic code of an organism
 Beneficial vs Harmful Mutations
 Physical Conditions
 If the environment changes, the organisms with favorable
traits to survive, will reproduce and pass on those traits.
 Those without the traits, most likely die or produce fewer
offspring.
 The greater the diversity of a species, the greater the chance
for survival during environmental changes.
 Geological Evolution: change in landforms over time.
 Theory of Plate Tectonics
 Movement of earth’s continental and oceanic plates
 Caused mountains and trenches to form which continually
shape the earth’s surface.
 Movement of the plates causes changes in climate,
geographic features, sea levels, and types of organisms in a
location.
 Pangaea
 Theory of Continental Drift
 Law of Superposition:
 In any undisturbed sequence of rocks deposited in
layers, the youngest layer is on top and the oldest on the
bottom.