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#1. List two similarities between trilobite’s A, B, C, D.
#2. List two differences between trilobite’s A, B, C, D.
#3. Explain a reason why trilobites A and D are
different, yet similar.
500 mya
450 mya
Chevalier de Lamarck
 French biologist and botanist, (1744-1829)
 Research led him to conclude that plants and animals
change over time to adapt to their environment. These
changes in organisms are passed on to offspring.
Charles Darwin
 British naturalist, (1809-1882)
 Naturalist aboard the H.M.S. Beagle from 1831 to 1836
 Studied the life and fossils found on the Galapagos Islands
Best known for studying finches.
Darwin

He was influenced by Lamarck’s research
 Based on his research in the Galapagos he suggested
the following theories:
(1) that evolution had occurred
(2) that most evolutionary change was gradual, requiring
thousands or millions of years
(3) that the primary mechanism for evolution was a process
called natural selection
(4) that the millions of species present on Earth today arose
from a single original life form through a branching
process called speciation, by which one species
can give rise to two or more species (Coyne, 2007).
Natural selection (commonly referred to as the
survival of the fittest) The theory that the organisms that survive to
produce offspring have inherited the most favorable
traits for survival in a particular environment.
 Led to the development of the theory of evolution.
Natural Selection
Brought about by:
Competition
Predation
Climate changes
Immigration/Emigration
What physical features makes
these organisms suited (or not
suited) for this environment?
What physical features makes
these organisms suited (or not
suited) for this environment?
Evolution- Theory; a process that
produces new life forms over time.
Gradualism- evolutionary processes take place
over millions of years in gradual and continuous
changes between organisms (millions to hundreds
of millions of years).
 Commonly accepted theory.
 Supported by Darwin.
 Fossil record is incomplete, it does not represent every evolutionary
change that took place.
Punctuated Equilibrium- evolutionary
processes occur in rapid, irregular spurts
(thousands to a few million years).
 Suggested by Stephen Gould (1941-2002).
 Fossil record has examples of rapid changes between species.
Creationism- is a set of beliefs
based on the idea that a Supreme
Being brought into existence Earth
and all its life through a direct act of
creation.
Why is evolution not a proven
theory or law?
• Gaps in the fossil record.
Side of classroom by door:
Brainstorm
three
arguments in
favor of
evolution.
Side of classroom by windows:
Brainstorm
three
arguments in
favor of
creationism.
How Are Fossils Formed?
Fossil- any remains, impression, or trace of
a living thing of a former geologic age, as
a skeleton, footprint, etc.
High probability of becoming a fossil if:
 Hard parts (bones, shells) vs. soft parts
(jellyfish)
Buried quickly
Index Fossil- fossils used to define and
identify geologic periods.
High probability of becoming an index fossil if:
 Easy to identify
Wide geographic distribution
Lived for a short time period
Gaia Lab
• Everything is connected!
• Butterfly effect
Banded Iron Formation
Oxygen in atomosphere
began between about 3.71.8 bya was oxidized
(oxidation is the reaction of
oxygen with another
substance).
On Earth, the free oxygen
combined with the free iron
to form “rust” in the
Banded Iron rocks.
When the free iron was
“used up,” oxygen was free
to accumulate in our
atmosphere.
Photosynthesis