Transcript Evolution Notes #2

Today’s Agenda
April 8, 2016
1. Evolution Notes Part
III
• 5 principles of evolution
Homework
Answer Questions on
the 5 Principles of
Evolution
Today’s Agenda
April 11, 2016
1. Evolution Notes Part II
• 5 principles of evolution
Homework
Answer Questions on
the 5 Principles of
Evolution
Evolution Notes: Part 2
First Theory of Evolution
• First developed by Jean Baptiste de Lamarck &
was known as the ‘Theory of Acquired Characteristics’
• Principles of Lamarck’s Theory:
– a. “offspring are born with traits from their
parents that the parent developed during their
lifetime”
• Ex: Elephants used to have short trunks but water and
food became difficult for them to reach. They stretched
their trunks to reach the water and food better. Their
offspring were then born with longer trunks.
– b. Evolution is a predetermined plan. The
results have already been decided.
First Theory of Evolution
• Lamarck’s theory is not accepted. It
was replaced by Darwin’s theory.
• Does Lamarck’s theory make sense? What’s
wrong with his theory?
• was correct in that offspring are born with
traits from their parents
• was incorrect in that those traits that
are developed over time can be passed
on to their offspring
• Lamarck did not understand heredity
(genes)
Today’s Accepted Theory of
Evolution
• Developed by Charles Darwin
• It is called the ‘Theory of
Evolution by Means of Natural
Selection’
• There are 5 main points to this
theory
Darwin first developed
his theory by studying
organisms in South
America & the
Galapagos Islands.
He published his book
On the Origin of
Species by Means of
Natural Selection in
1859
Darwin’s Theory of Evolution
by Means of Natural Selection
Five (5) Principles
Principle #1
#1: Organisms produce more
offspring than can survive
- This is to increase the chance that
some will survive to pass on genes,
which is the goal of all living things.
• Example 1: Frogs
What could happen to
some of these
offspring?
• Example 2:
Peppered Moths
What could have
happened to these
moths?
Principle #2
#2: Variations are found among
individuals of a species
What is a Variation?
• A variation is a difference between
members of the same species.
– For example, fur color in squirrels & body
color in moths.
Black Variation
White Speckled Variation
Principle #3
#3: Variations are passed down to
offspring
These baby
squirrels inherited
their grey color from
their parents
Generation 1 has
both black and
white speckled
moths surviving
Both Generations 2
& 3 have black and
white speckled
moths because
both variations
were passed down
from Generation 1.
Principle #4
#4: Some variations allow members
of a population to survive and
reproduce better than others.
*These are called adaptations - Helpful
Variations!*
Which variation is the adaptation? Why?
Grey Eastern Grey
Squirrel
Albino Easter Grey
Squirrel
Black Eastern Grey
Squirrel
Before Industrial
Revolution, the white
speckled variation was
the helpful trait
(camouflage).
During Industrial
Revolution, the black
variation was the helpful
trait (camouflage).
Principle #5
#5: Over time, offspring of
individuals with helpful variations
make up more and more of a
population
Points of Natural Selection…
1. The environment does not cause
INDIVIDUALS to change.
1. The environment causes an entire
SPECIES to change by changing the
circumstances by which the
variations survive. This changes the
population of one of the
variations!
Points of Natural Selection…
3. In other words, a whole SPECIES
ADAPT and INDIVIDUALS either
SURVIVE or DIE.
3. If all the INDIVIDUALS DIE, the
SPECIES goes EXTINCT (could not
adapt).
Today’s Agenda
April 11, 2016
1. Natural Selection in Action
•
•
•
Galapagos
Peppered Moth
Rock Pocket Mouse
Homework
Answer Questions on
the 5 Principles of
Evolution
The Elephant
Man- Proteus Syndrome
Joseph
Merrick
• Less than 1 in a million
people
• A few hundred
reported cases
• A genetic RANDOM
mutation NOT inherited
• Cells are UNABLE to
regulate their growth
• Abnormal growth of
fatty tissue, bones &
skin
Natural Selection in Action
• Galapagos Island Finches:
Peppered Moths
• Rock Pocket Mouse:
Today’s Agenda
April 12, 2016
1. Natural Selection in Action
•
•
•
Galapagos
Peppered Moth
Rock Pocket Mouse
Homework
Answer Questions on
the 5 Principles of
Evolution
Homework Questions
1. Why can’t a horse and a donkey be in the
same species?
They can NOT produce fertile offspring.
1. Why Lamarck’s ‘Theory of Acquired
Characteristics’ is wrong?
Traits are NOT developed during adulthood.
1. Why do organisms produce more offspring
than can survive?
To INCREASE the odds that some will
SURVIVE to pass on their genes
Homework Questions
4a. Write the definition for variation.
A DIFFERECE between members of
the SAME species
4b. Give at least 2 examples of
variations in a population of humans.
Hair color, eye color, skin color
Homework Questions
5a. Write a definition for ‘adaptation’.
A variation that allows members of a
population to survive and reproduce
better than others
5b. State an example of an adaptation
that a squirrel has. Explain why it is an
adaptation.
Color of fur helps to blend in with
surroundings (camouflage)
Homework Questions
6. Explain why albinism is NOT an
adaptation.
It’s NOT adventageous
7. Below are 3 individuals of the species
Eastern Grey Squirrel. Which is the least
likely to survive in any environment? Why?
Grey Eastern Grey
Squirrel
Albino Easter Grey
Squirrel
Black Eastern Grey
Squirrel
1. Why do organisms produce more
offspring than can survive?
Organisms produce more offspring
than can survive to INCREASE the
chances that an offspring will survive
and pass on the parent’s genes.
2. Define variation:
Variation is a difference in
members of the same species.
• Give an example of
variations in a population
of snakes.
Examples of variations are colors
and patterns of a snake’s skin.
3. Define adaptation:
An adaptation is a HELPFUL variation.
A. Give an example of an adaptation that a
snake has. Explain why it is an adaptation.
An example of an adaptation that a snake
has is a flexible jaws, rattling, and hissing
4. There are three individual species of Eastern Grey
Squirrel – Grey Eastern Grey Squirrel, Albino Eastern Grey
Squirrel and Black Eastern Grey Squirrel.
a. What is the variation of these squirrels?
Color is the variation of these squirrels.
b. If these three types of squirrels lived in the
woods in Milford, which would have the
adaptation and why?
The gray squirrel because it can camouflage.
c. Which squirrel is the least likely to survive in
Milford and why?
The white squirrel because it canNOT camouflage.
Natural Selection: a natural process resulting in the evolution
of organisms that are best adapted to the environment.
There are three types of polar bears: one with thick
coats, one with thin coats and one with medium
coats. It is fall, soon to be winter. The
temperatures are dropping rapidly and the bears
must be kept warm, or they will freeze to death.
Many of the bears have had 2 cubs each but due to
the extreme temperatures, many mothers only
have one cub left.
1. Which polar bear will NOT benefit from
natural selection?
The one with thin fur.
2. Identify the type of variation in the polar
bear population. A type of variation in the
polar bear is fur thickness.
3. Who is the most fit for her environment?
The most fit for the environment is the
polar bear with thick fur.
3. Predict how the gene pool will change over
with
thewith
polarthick
bears?
Thetime
polar
bears
fur will most likely be
the ones to survive and pass on their genes.
1
2
3
5. Describe what is happening in figures 1 – 3.
(What is happening to the mice and the hawk?)
The hawk is hunting the black mice because
the hawk can see them better. The white
mice camouflage with the white background.
1
2
3
6. Is the population (amount) of mice different in
figure 3 than in figure 1? Explain your answer.
The population of white and black mice is
the same in figure 1. There are 4 of each
variation. In figure 3 the population of black
mice decreased and the population of white
mice has stayed the same.
7. Living things that are well adapted to their
environment survive and reproduce. Those that are
not well adapted don’t survive and reproduce. An
adaptation is any characteristic that gives the living
thing the ability to survive and reproduce. What
characteristic of the mice is an adaptation
that increased (made better) their chance of
surviving and reproducing?
The mice that have white coloring have the
adaptation to survive in the white
background. They are the ones that are able
to pass on their genes to their offspring.
8. An inherited characteristic that helps an animal or
plant have more offspring will tend to become more
common in a population as a result of evolution by
natural selection. Explain why a characteristic which
helps an animal to live longer will generally tend to
become more common in the population as a result
of evolution by natural selection. (Why are there
more white furred mice than black furred mice?)
The animal or plant that is best adapted to
survive will be the one to pass on their genes
to their offspring. They are the ones that are
alive to pass on their genes.