Biology: Evolution, The Theory Of Natural Selection and Evidence

Study Guide-Natural Selection/Evolution & Evidence

1. Define evolution:

DEFINITION: The process by which a species slowly begins to adapt or change to certain constraints to help it survive.

2. What scientist theorized that evolution is driven by natural selection? CHARLES DARWIN

  1. What was the name of his book?

    • On The Origin of Species

  2. What was the name of the ship he traveled on?

    • HMS Beagle

  3. Most of his research was done on the Galapagos Islands where he studied finches and tortoises

8. What is natural selection? 

The process by which a species get naturally determined by nature, the animals that have the best fitting traits will survive and pass those traits on. NATURE DECIDES WHO LIVES AND WHO DIES.

The process by which a species evolves by best fitting within an environment for survival.

9. Describe the key components of Darwin’s theory of Natural Selection

a. Genetic Variation- we need the populace to have difference (i.e. different fur thickness, different fur color, etc.) variation within a population

b. Overproduction- more babies born than can survive

c. Competition- a group or species competing for mates, shelter, food, etc. competition is normal.

d. Differential Reproduction- the organisms that have successful adaptations will live produce and make more!!!!!!


10. What is an adaptation? Define fitness. 

An adaptation is something that helps an organism survive within the certain environment

FITNESS: good fitness means you fit within that population


11. How does an adaptation impact fitness?

if you have adaptations that are beneficial to your environment you will become more fit and survive, the reciprocal for not beneficial



A. Fossil Record – 

1. Fossils are used to trace the evolutionary development of organisms.  Circle the Transitional Fossils.


2. Explain how fossils are made: 

Fossils are made: not need to be explaioned

3. Where do we find fossils?

SEDIMENTARY ROCK

4. What types of information can we get from fossils?

What types of organisms existed, and how long ago did they live, they give a good baseline for what and when!


B. Comparing Anatomy between species:

  1. Define Homologous Structures

have a similar structure, but they do different things. tells us they evolved from a common ancestor. DIVERGENT EVOLUTION

  1. What can you conclude about the 

relationship between penguins, 

alligators, bats, and humans?

they have homologous structures so they must be closely related

      3. Define Analogous Structures

the bones or interior structure may not be the same, but they do the same thing! its fraudulent 👿

  1. Using the diagram to the right, explain why the 

pterodactyl, bat, and bird did not come from a

 common ancestor.


the bones are not laid out in the same spots, they are 

structurally different, it is likely there is no common

ancestry.








  1. Define Vestigial Structures; give an example of a vestigial structure.

A structure that the species or organism has adapted to not need it anymore, so it serves no use.


5. Comparing embryological development:

What can you conclude about the evolutionary

you can conclude that they are closely related, because they are similar and look similar at THIS stage of development.

relationships between these organisms?

yesm they are alike.





6. Comparing biochemistry:

What can you conclude about

the evolutionary relationship

between the horse and zebra?

they are closely related, they have

one difference in the amino acids.




7. 2 Types of Evolution:

  1. Define Divergent Evolution – 

when you diverge or come away from a common ancestor

  1. Define Convergent Evolution – 

 the species that are not closely related, do not come from a common ancestor, evolve similar traits DUE to their environments.










Which example is divergent evolution? A or B? AAAAA

Which example is convergent evolution? A or B? BBBBBB