1. Origins of Life
Geology & Evolution Review
- Age of Earth Theories -

2. Age of the Earth Assumptions
 Science involves a lot of guesswork
 Presuppositions affect research outcomes
 Scientists with different beliefs look at the same data and
come to very different conclusions
Assumption of Assumption of All theories of
Evolution Creation
Earth’s origins
are based on
Scientific Data assumptions &
theories that
can never be
Evolution is Intelligent Design proven
Seen is Seen

3. Age of the Earth: Evolution
Many scientists today believe that:
• Humans began to evolve 1.4 million years ago
• Fish were seen about
500 million years ago
• Earth’s first life forms
appeared 3.5 billion
years ago
• Our planet is roughly
4,600,000,000 years
old

4. In 1859, Darwin published his theory of
evolution in "The Origin of Species"
• Theory not readily accepted
 Earth not believed to be old enough
 Scientists look for clues that suggest Earth is very old
• Now scientists use fossil and geologic records to construct
a very long history of life on Earth

5. Age of the Earth: The Bible
• Bishop Ussher (in 1654) estimated Earth was created 6000
years ago (in 4004 BC) - based on the Bible & historical documents
• Most Creationists now estimate earth’s
age to be about 10,000 years old
- based on historical documents & scientific
evidence
Bishop Ussher
(1581-1656)

6. Age of the Earth: Theistic Evolution
Some scientists think evolution and
the Bible fit together perfectly
• Genesis creation account a
metaphor (not a literal 6 days)
• God supernaturally initiated the
evolutionary process
 created universe
 "planted" DNA on Earth

7. Age of Earth Research
 All these theories still being researched
• Theories change based on new data and findings
• Don’t be too hasty to judge until you've really studied all the facts
 All these theories require a certain
amount of faith

8. Primordial Soup
 Assumes ancient earth atmosphere
of ammonia, hydrogen, methane and
water vapor
• volcano-like environments
 Lightning striking methane gas could
form organic compounds
• Amino acids, ATP, sugars and nitrogen
bases synthesized from cyanide in lab
experiment
 These simple molecules could
arrange themselves into small,
single-stranded strips of RNA which
in turn produce DNA
 Problems:
• 2nd Law of Thermodynamics (entropy)
• Early atmosphere now believed to contain
CO2 & O2

9. Endosymbiont Theory
 If a prokaryote ingested some aerobic bacteria, it's possible that they
formed a symbiotic relationship that helped them both survive better.

10. Extraterrestrial Seed Theory
 Complex DNA coding would have
been necessary for even the
hypothetical first simple cells.
 DNA evidence speaks of intelligent,
information-bearing design.
• Extra-terrestrial civilization
sent/brought DNA to earth
 Panspermia - "seeds everywhere"
• archaebacteria, which can be dormant
and withstand harsh environments,
could have existed on another planet,
making its way to Earth via space dust
(meteorites) instead of originating
here

11. Big Bang Theory
 A cosmic explosion (or expansion) hurling matter in all
directions created the universe 10-20 billion years ago
Evidence
• distant galaxies are traveling away from
us at great speeds
• Cosmic radiation (from the explosion?)
can be observed
Problems
• 1st Law of Thermodynamics – energy can
neither be created nor destroyed
• Entropy (2nd Law) – every life process
increases the disorder and disorganization
of matter (unless there is some sort of
intervention)
• Doesn’t account for organic (living)
matter, only gas
Probably will never be proven or dispelled
– not a testable theory

13. Review: Earth/Fields of Study
 Archeology
• The study of Artifacts
 Paleontology
• The study of Fossils
 Geology
• The study of Rocks & Earth's composition/history
 Embryology
• The study of embryos (pre-born organisms)
 Which parts of Earth are
• SOLID inner core & crust
• LIQUID outer core
• SEMI-SOLID mantle

14. Review: Rock Cycle
 What are the 3 major rock types?
• Sedimentary
• Metamorphic
• Igneous
 What are the steps involved in the
formation of Sedimentary rocks?
• Weathering
• Erosion hint: WED B/C/C
• Deposition
• Burial/Compaction/Cementation
 Give an example of weathering
• physical, chemical & biological (tree roots, freezing water, animals burrowing, rust,
acid rain, waves crashing, etc.)
 What is erosion?
• soil and sand carried away by water, wind, glaciers, landslides, etc.
 Name some ways sediments are deposited.
• settling of biogenic ooze, melting icebergs & glaciers, volcanic eruptions, estuaries,
evaporation

15. Review: Rock Cycle
 Describe the process of Burial, Compaction & Cementation.
• Layers buried under new sediment
• Particles pressed together by weight of water/sediment above
• Sediment cemented by minerals crystallizing between particles
 What forces produce metamorphic rock?
• Heat & Pressure
 What types of rock can become
metamorphic rock?
• all types
 What is produced when rock is melted
into a semi-solid form?
• magma
 What is the difference between an igneous intrusion & igneous
extrusion?
• intrustion: magma that comes up but never reaches the surface (dike/sill/batholith)
intrustion
• extrusion: magma that is spewed or flows out of the crust (lava)
extrusion

16. Review: Fossils
 What is a fossil?
• Evidence of organisms that once lived on Earth
 Where are most fossils found?
• In sedimentary rock (also tar pits, amber or frozen in ice)
 Explain what a MOLD & CAST fossil is?
• organism is buried in mud and disintegrates, leaving a hollow mold which later fills with sediment
 Give an example of a TRUE FORM fossil.
• insect incased in amber or frozen wooly mammoth
 How does PETRIFACTION occur?
• plant or animal remains are covered with water, and over time minerals from the water are absorbed into it and solidify
 Name some examples of TRACE FOSSILS.
• T-Rex footprints, feeding marks, dino poo, tree root cavities, roundworm burrows

17. Review: Geologic Time
 What are some ways a scientist might
estimate the age of a fossil or rock layer?
• Stratigraphy
• Dendrochronology
• Radioisotope dating
• Molecular clocks
• Index fossils
 Explain the difference between
RELATIVE AGE and ABSOLUTE AGE.
• Relative: compares index fossils and rock layers (stratigraphy) to give an "older
Relative
than" or "younger than" estimation
• Absolute: uses Dendrochronology & Radioisotope dating to give an estimated
Absolute
number of years old
 What does the principle of superposition assume?
• that younger rock layers and fossils are deposited on top of older fossils & rocks

18. Review: Geologic Time
 What assumptions have
been made in the
formation of the GEOLOGIC
COLUMN pictured here?
• slow, even sedimentation
rates (no hydrologic sorting
or catastrophic events)
• radiometric dating of rock
layers is accurate
• index fossils are reliable
indicators to date rock layers
• lack of transitional fossils &
gaps in fossil record are due
to periods of rapid evolution

19. Review: Paleontology Viewpoints
Phyletic Gradualism (Uniformitarianism)
 "The present is key to the past"
 Slow sedimentation rates remain relatively constant throughout history
• .2 - 100 cm of sediment laid down per 1000 years
• takes millions of years for sedimentary rock layers to form
Phyletic Discontinuity (Catastrophism)
 Catastrophic events cause rapid, widespread sedimentation
• volcanoes, floods, ice ages, etc.
• hydrologic sorting produces distinct rock layers with different fossils
Punctuated Equilibrium
 Slow sedimentation rates and evolutionary changes "punctuated"
(interrupted) by catastrophic events and rapid evolution
• Explains mass extinctions, "Cambrian Explosion" & lack of transitional fossils
 Sudden disappearance of certain species
 Sudden appearance of new species (fossils)
 Rapid evolution triggered by sudden environmental changes

20. Review: Classification
 What are the 8 levels of classification?
Hint: Did King Philip Came Over For Good Soup?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
 What is the type of
evolutionary grouping
shown here called?
• a cladogram
(Tree of Life)

21. Review: Phylogenetic Classification
 3 Domains in the "Tree of Life"
• Bacteria
• Archaea
• Eukarya
 6 Kingdoms?
• True bacteria
• Ancient bacteria
• Protists
• Fungi
• Plants
• Animals
 What do scientists look at when trying to classify organisms
into clades?
• morphology
 homologous & analogous features
• embryological development
• genetic similarities
• the fossil record

22. Review: Evolution
 What does "descent with modification" mean?
• Given enough time, many small changes in the gene
frequency of a species result in big changes within a
population, resulting in speciation
 What adaptations are passed between
generations?
• Only inherited (genetic) traits are given to offspring
 What are 3 mechanisms of
evolutionary change?
• genetic variation
• natural selection
 adaptations that increase fitness are "chosen" by the
environment to be passed on via reproduction
• genetic drift
 random changes in gene frequency

23. Review:
Genetic Variation
 Evolutionary change can ONLY happen with
changes to the genes of a population.
 What are 3 sources of variation?
• Mutation
 caused by errors in DNA replication,
increased by exposure to mutagens
• Gene Flow
 genetic exchange due to migration
of individuals
• Sexual Reproduction
 meiosis:
• crossing over
• independent assortment

24. Review: Natural Selection
 How does it work?
• A change in traits occurs
 due to genetic variation
 i.e. a green beetle has brown baby
• There is differential reproduction
 environmental changes affect who survives to
reproduce
 i.e. green beetles get eaten by birds, so only brown
beetles survive to reproduce
• Inherited traits are passed on
 i.e. surviving brown beetles have brown babies
because this trait has a genetic basis
 What is an ADAPTATION?
• a feature that becomes common in a population
because it provides some improved function
necessary for survival and/or reproduction
 What is evolutionary fitness?
• the ability to survive and reproduce

25. Review: Evolution
 What is the likelihood of a mutation being beneficial?
• extremely small - most mutations are neutral, harmful, or lethal
 Which cells in an organism pass on their DNA to offspring?
• gametes (egg, sperm, pollen, etc. - reproductive cells)
 What contributes to an organism "FITNESS"?
• ability to compete for resources
• health/hardiness
• reproductive success
• predator evasion
• resistance to disease, starvation, effects of aging
 What is extinction?
• when a species (and their DNA) fails to survive (they all die)

26. Review: Types of Evolution
 What is microevolution?
• changes in traits (and gene frequency) within a species
 Name some examples of microevolution.
• Peppered moth industrial melanism, beetle colors, Darwin's
finches, antibiotic-resistant bacteria
 What is macroevolution?
• changes above species level
 Name some examples of macroevolution.
• ferns  pine trees, fish  amphibians, dinosaurs  birds, whales 
horses **never observed in nature
 What is coevolution?
• when two different species affect each others' adaptations
 What close relationships between organisms could
contribute to coevolution?
• Competitive, mutualistic, predator/prey, parasite/host

27. Review: Age of Earth Theories
• How old do "Young- • How old do Evolutionists
Earth" Creationists estimate earth’s age to
believe earth to be? be:
about 10,000 yrs about 4,600,000,000 yrs
• What is Theistic Evolution?
a theory of creation that assumes each "day" of creation was perhaps
millions of years long
incorporates the idea of evolutionary formation of living species but
identifies a Creator (God) as the instigator (DNA-planter?)