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ANIMAL ADAPTATIONSOrganisms have a great variety of internal and external structures
that enable them to survive in a specific habitat (e.g., echolocation, seed dispersal, skull diversity). (C.S. 3.2; 5.2 & 4.1)
Mrs. TrotterVian Middle School
Peppered Moth
Which mice are easily spotted?
Resistance Building
In humans
More vestigial structures
How many people have wisdom teeth?
Fossils
Fossils provide important evidence of how life and environmental conditions have changed (e.g., Law of Superposition, index fossils, geologic time period, extinction). (C.S. 5.2)
How do fossils form
Actual fossils
The law of superposition
Essentially it says that the older rock is going to be located on the bottom
Watch this example of how rock layers can change
Notice the layering of rocks
It would be helpful if the layers were left undisturbed…
But we live on an constantly changing Earth!
Some are easy geologic problems
Like faults
Or Molten lava flows
You can make your own model
Law of Superposition
Started from the Bottom
A silly song to help “rap” up
the problem
Relative Dating
If the younger rocks are on top and the older rocks are on bottom
If the rocks are undisturbed We can guess or relatively date the age
of a fossil
You wouldn’t
find modern artifacts
at the bottom layers
Index Fossils
The Trilobite fossils
One day someone may find something you have left behind
Fossil Record
Right now our fossil record is incomplete Fossils are hard to find Rarely do people agree on the age We merely make an educated guess
How do scientist determine the age of the Earth?
Until recently, astronomers estimated that the Big Bang occurred between 12 and 14 billion years ago. To put this in perspective, the Solar System is thought to be 4.5 billion years old and humans have existed as a genus for only a few million years. Astronomers estimate the age of the universe in two ways: 1) by looking for the oldest stars; and 2) by measuring the rate of expansion of the universe and extrapolating back to the Big Bang; just as crime detectives can trace the origin of a bullet from the holes in a wall.
You believe what you want to believe It’s your choice That is the great thing about being free and
living in America Just keep an open mind and consider all the
options and angles Also consider the educational
background/religious/atheistic beliefs of those trying to persuade you
Learning about things-even if you don’t agree- makes gives you a well rounded education
Turn to the back page of your worksheet!
We will answer #’s 1-4
Importance of Fossils
Fossils give us proof of preexisting life, and clues to what the environment might have been like
Lamarck’s hypothesis of acquired characteristics
He suggested that characteristics or traits, developed during a parent organism’s lifetime are inherited by its offspring
Darwin’s theory of evolution by Natural Selection
Natural selection means that organism with traits best suited for their environment are more likely to survive and reproduce
Gradualism
Describes evloution as a slow ongoing process by which one species changes to a new species
Punctuated equilibrium
A model that shows rapid evolution comes about when the mutation of a few genes results in the appearance of a new species over a short period of time
