Transcript Slide 1

I used the law
of
superposition
and crosscutting
relationships
to arrange the
rock layers in
chronological
sequence.
Exponential Decay Graph For
Radiometric Dating, by Mr. Naugles
This is a print-screen from an Excel Spreadsheet File
Intrusion A is 2 half-lives old = 1.408 byo.
Absolute Dating is Radiometric uses
y=(0.5)x
an Exponential Decay Function. Based
on the measurements that showed
only ¼ of the parent material
remained, I reasoned that two halflives had passed since intrusion A was
formed. This meant that older layers
are older than 2 half-lives.
Life developed on Earth
3.6 billion years ago.
Early eukaryotes
were the first cells on
earth to have a
nucleus, about 1.8
billion years ago.
Oxygen from
cyanobacteria was
changed to ozone by
UV light, creating the
protective ozone
layer that allowed
other life to live
without getting toxic
sunburn. I noticed
that mammals
appeared earlier than
flowering plants in
the fossil record.
In the environment
where there were
equal amounts of
tan and brown
ground cover, the
number of brown
versus tan beetles
stayed about
equal. However,
in environment 2
and 3, the color
that better
matched the
ground cover
allowed the
beetles to survive
and reproduce
more successfully.
After counting the beetles of
each type, over three
different generations in
three different
environments, I found that
the beetles whose color
matched the leaves
increased in number. The
beetles whose color did not
match the leaves decreased
in number.
The environment determined
the proportion of
brown:tan beetles,
probably because predators
can see and eat contrasting
beetles more easily than
predators can eat beetles
with a color that matches
or blends-in. When
predators can see
something that is clearly a
beetle, they are more likely
to eat the beetle. If the
predators cannot see the
beetle as easily, they are
less likely to eat the beetle.
Surviving to reproduce requires that beetles do not get
eaten. Beetles that survive to reproduce create the next
generation, causing color proportion to change with color
changes in the beetles’ environment.
History of Earth and Life with
Evolution,
by Fulano Sabelotodo, period 2
• Studying Earth’s Past involves relative dating
and radiometric dating.
• Understanding the history of Life on earth
involves understanding the Geologic Time
Scale. Mammals appear in the fossil record
earlier than flowering plants.
• Evolution is the gradual change in species over
time. Beetle color can change, over many
generations, to match the environment, when
the environment changes.