Name: __________________________________________
Date: _________________________
Evolution Notes
Bell Work:
1. How would you define evolution? ____________________________________________________________
__________________________________________________________________________________________
2. What evidence have you heard of that supports the theory of evolution? ______________________________
__________________________________________________________________________________________
3. What makes evolution possible? _____________________________________________________________
__________________________________________________________________________________________
4. What is natural selection? Can you give an example? _____________________________________________
__________________________________________________________________________________________
5. How would selective breeding play a role in evolution? ___________________________________________
__________________________________________________________________________________________
NOTES:
Evolution: ________________________________________________________________________________
Lamark’s Theory:
 Lamark thought that animals could adapt to their environments and then pass these acquired
characteristics along to their offspring.
 For example: He thought that giraffes couldn’t reach the leaves on tall tree, so they stretched their necks
until they got longer. Then these giraffes passed this trait on to their offspring.
 We know that can’t be true because you only pass on your DNA to your offspring.
 If you have surgery to make you taller this is not in your genes and cannot be passed on to your
offspring.
Darwin:
 In 1831 Charles Darwin went for a boat ride on the H.M.S. Beagle.
 On this trip he notices many he began to wonder why organisms seemed so well suited for their
environments.
 He collected fossils as well as living specimen.
 Finally in 1859, Darwin publishes his theory of evolution in his paper “On the Origin of Species”
Theory of Evolution:
 There is natural variation among different organisms within a species.
 This variation is cause by meiosis (crossing over and Mendel’s Laws) and fertilization
(combining new traits from two different organisms) and mutations (changes in the sequence of
DNA)






 Adaptations are variations that occur and make an organism better suited to survive and pass on
its genes
Organisms compete with each other for survival, causing natural selection.
Natural selection – the organisms with the traits that are most beneficial will survive to reproduce and
pass on those traits, while the others will die off.
This is also know as survival of the fittest
Over time, natural selection changes the inherited characteristics of a population, so modern organisms
look different from their ancestors
Taking this a step further, Darwin proposed common descent
 That all organisms evolved from one common ancestor
Evidence used to support this theory of common descent:
 Fossil Record – by looking at structures left behind by previous organisms we can show the
changes within species and try to make links and find common ancestors
 Geographic Distribution of Living Species – many organisms across the world are very similar,
yet have distinct differences that make them more suited for their particular environment
 Homologous Structures – structures that serve different functions, but are structurally similar
 Early Development – most embryos with a backbone go through very similar stages during
development and look very similar
Artificial Selection:
 Sometimes humans interfere with natural selection (we’ve already talked about this because of selective
breeding)
 We breed organisms based on traits that would normally not be selected in nature.
 Ex: We choose cows that produce more milk, dogs that have a gentle demeanor, crops that taste
better or produce more, etc . . .
 What other examples of artificial selection can you think of?
Rates of Evolution:
 Evolution is a slow process.
 Gradualism – Some scientists speculate that the genetic changes occurring in species occurs at a
constant rate very slowly. They speculate that evolution is a process like erosion. It causes huge changes
because tiny changes are occurring constantly.
 Punctuated Equilibrium – Other scientists speculate that there are long periods where nothing happens,
but occasionally big changes in species occur. These could be because of dramatic changes in the
climate such as an ice age or due to natural disasters.
Patterns of Evolution:
 Convergent Evolution – when two species develop similar traits because they play similar roles in the
environment. These adaptations are not similar because they share a common ancestor!
 EX: sugar gliders in Australia and flying squirrels in North America
 Divergent Evolution – when two species do share a common ancestor, but change drastically because of
their different niches, or roles in the environment.
 EX: finches on the Galapagos Islands
 Phylogeny – evolutionary history of an organisms or group of organisms
Video Questions:
1. What things do you think would help a zebra survive?
2. What things do you think help the lions survive?
3. Is this natural or artificial selection? How do you know?
4. What zebras did the lions attack?
5. If I told you that lions were colorblind, what other trait do you think has developed in the zebra population
to help them survive?
Discussion:
1. Is there natural selection within the human population?
2. If so, what traits are selected for in humans?
3. Moth example:
a. Before the industrial revolution which moths thrived?
b. After the industrial revolution which moths thrived?
c. Is this natural or artificial selection? Explain.
4. Why is biodiversity important?
Name: __________________________________________
Date: _________________________
Evolution Notes
Evolution: ________________________________________________________________________________
__________________________________________________________________________________________
Lamark’s Theory:
 Lamark thought that animals could ________________ to their environments and then pass these
_______________________ characteristics along to their _______________________
 For example: He thought that ____________________ couldn’t reach the leaves on tall tree, so they
____________________ their necks until they got ___________________. Then these giraffes passed
this __________________ on to their offspring.
 We know that _______________ be true because you only pass on your ___________ to your offspring.
 If you have ______________________ to make you ___________________ this is not in your
_____________ and cannot be passed on to your offspring.
Darwin:
 In 1831 Charles ____________________ went for a boat ride on the H.M.S. __________________.
 On this trip he notices many ____________________ organisms, he began to wonder why organisms
seemed so __________ suited for their ____________________________
 He collected ___________________ as well as ______________________ specimen.
 Finally in 1859, Darwin _______________________ his theory of _________________________ in his
paper “______________________________________________”
Theory of Evolution:
 There is natural __________________________ among different organisms within a _______________
 This variation is cause by ___________________ (_________________ _____________ and
Mendel’s Laws) and fertilization (combining __________ traits from two __________________
organisms) and _______________________ (changes in the sequence of DNA)
 Adaptations are _______________________ that occur and make an organism
_______________ suited to ___________________ and pass on its _________________
 Organisms ______________________ with each other for survival, causing ____________________
_____________________
 Natural selection – the organisms with the ________________ that are most ___________________
will survive to _______________________ and pass on those traits, while the others will ________ off.
 This is also know as ______________________ of the _____________________
 Over _______________, natural selection changes the ______________________ characteristics of a
_______________________, so modern organisms look ______________________ from their
______________________
 Taking this a step further, Darwin proposed __________________ ______________________
 That all organisms ________________________ from one common _____________________
 Evidence used to support this theory of common descent:
 _______________ Record – by looking at ___________________ left behind by
________________ organisms we can show the ________________ within species and try to
make _______________ and find common ancestors
 Geographic Distribution of ___________________ Species – many organisms across the
_____________ are very similar, yet have ____________________ differences that make them
more suited for their particular ______________________
 __________________________ Structures – structures that serve different _________________,
but are __________________________ similar
 Early _________________________ – most ________________ with a backbone go through
very similar stages during development and look very similar
Artificial Selection:
 Sometimes __________________ interfere with __________________ selection (we’ve already talked
about this because of ______________________ _______________________)
 We _____________ organisms based on traits that would normally not be selected in _______________
 Ex: We choose cows that produce more _______________, dogs that have a ________________
demeanor, crops that taste better or produce more, etc . . .
 What other examples of artificial selection can you think of?
Rates of Evolution:
 Evolution is a ______________ process.
 Gradualism – Some scientists speculate that the ____________________ changes occurring in species
occurs at a ____________________ rate very slowly. They speculate that evolution is a process like
_________________. It causes _____________ changes because tiny _________________ are
occurring constantly.
 ________________________ Equilibrium – Other scientists speculate that there are ______________
periods where ____________________ happens, but occasionally __________ changes in species
occur. These could be because of dramatic changes in the _____________________ such as an ice age
or due to natural _____________________.
Patterns of Evolution:
 _______________________ Evolution – when two species develop _________________ traits because
they play similar ______________ in the environment. These ______________________ are not similar
because they share a ______________________ ancestor!
 EX: sugar gliders in Australia and flying squirrels in North America
 Divergent ______________________ – when two species do _______________ a common
___________________, but change _________________________ because of their different
______________, or roles in the environment.
 EX: finches on the Galapagos Islands
 Phylogeny – evolutionary ____________________ of an organisms or group of organisms
Critical Thinking Questions:
1. How would you define evolution? ____________________________________________________________
__________________________________________________________________________________________
2. What evidence have you heard of that supports the theory of evolution? ______________________________
__________________________________________________________________________________________
3. What makes evolution possible? _____________________________________________________________
__________________________________________________________________________________________
4. What is natural selection? Can you give an example? _____________________________________________
__________________________________________________________________________________________
5. How would selective breeding play a role in evolution? ___________________________________________
__________________________________________________________________________________________
Discussion:
1. Is there natural selection within the human population?
2. If so, what traits are selected for in humans?
3. Moth example:
a. Before the industrial revolution which moths thrived?
b. After the industrial revolution which moths thrived?
c. Is this natural or artificial selection? Explain.
4. Why is biodiversity important?
5: In the space below, draw a family tree (Grandparents, parents, great grandparents, aunts, uncles, nieces,
nephews, children, etc). Below it, save space to EXPLAIN who is DECENDENT from whom. (Look that
word up if you don’t know it.)