1. Evolution Notes

2. Yes it is…. Evolution is ‘just’ a theory isn’t it?
but what is a theory anyway?
Popular Definition of a Theory - a “_____” or “hunch”.
guess
Scientific Definition of a Theory - a well-substantiated __________ of an aspect of the natural world.
Scientific Theories are based on _______, facts, and have been ______ in many ways.
explanation
evidence
tested

3. Where did the Theory of Evolution come from?
The theory of evolution was thought of by both _______ ______ and ______ ______ _______.
Charles Darwin
Alfred Russell
Wallace

4. Charles Darwin studied traits of organisms on the ________ Islands and developed the theory of evolution by ______ ________.
Galapagos
natural selection

5. survival of the fittest
Alfred Russell Wallace studied traits of organisms on the _____ Archipelago of islands and coined the term “__________________”.
Malay
survival of the fittest

6. This is an Agrias butterfly from South America
What is Evolution?
Evolution is the process of species _______________ to better suit their environment.
Species: a group of organisms that can ____ with one another to produce ______ offspring.
changing over time
This is an Agrias butterfly from South America
mate
fertile

7. Mutations: ______ to an organism’s DNA made during ______.
Species change over time because of ________ and ______________.
mutations
natural selection
Mutations: ______ to an organism’s DNA made during ______.
Mutations create ________ in a population.
changes
Point of Mutation
meiosis
variations

8. Which color variation do you think is better suited to survive?
Natural Selection
In Natural Selection organisms with favorable _____ best suited to their environment are more likely to ______ and _________.
traits
survive
reproduce
Which color variation do you think is better suited to survive?

10. The Process of Natural Selection
1. Overproduction: organisms in a population produce more ________ than their environment can support.
Not all offspring will ______ long enough to reproduce.
offspring
survive
Green Sea Turtles lay 100 eggs in a “clutch”
Only one or two will survive to adulthood

11. The Process of Natural Selection
2. There must be ________ within the species.
Variation: _________ among _____ between individuals of the same species.
variations
differences
traits

12. Variations must be _______ from an organism’s parents.
inherited

13. The Process of Natural Selection
3. Organisms _______ to ______ in their environment.
Starvation, ______, competition & ________ limit populations of all species.
struggle
survive
disease
predation

14. helpful traits survive environment reproduce
Organisms that survive the struggle have ______ variations of _____ (adaptations) that help them ______.
Adaptations: features that make an organism suited for its __________ so it can survive, _________, & pass its genes/ alleles onto its offspring.
helpful
traits
survive
environment
reproduce
The environment changes and it becomes too cold for dogs with short and medium fur.

15. What is the flies adaptation?
Here’s an example of Evolution in action. This is happening all over the world!
What is the flies adaptation?

16. The Process of Natural Selection
4. Selection (successful reproduction): The members of a population that have ________ helpful variations of traits will be more likely to ______ and ________.
inherited
survive
reproduce
A saddleback tortoise from Pinzón Island

17. How do new species form? speciation one evolves two species
That’s called _________: the formation of a new species as a result of evolution.
Speciation occurs when ___ species ______ into ___ different ______ that can’t reproduce with each other anymore.
speciation
one
evolves
two
species

18. group separated caused movement plates
How do new species form?
1. Separation - when a _____ of individuals becomes _________ from the rest of the population. Can be ______ by a newly formed canyon, mountain range, lake or ________ of Earth’s tectonic _____.
group
separated
caused
movement
plates

19. groups affected selection Different traits favored spread
How do new species form?
2. Adaptation - Separated ______ continue to be ________ by natural ________ in their new, different environments. ________ _____ can be _______ and over many generations can ______ through the population.
groups
affected
selection
Different
traits
favored
spread
Kaibab squirrel
Abert squirrel
The formation of the grand canyon separated the Tassel-Eared squirrel population. Over time the different environments favored different traits causing the formation of two new species.

20. successfully How do new species form? populations mate two different
3. Reproductive Isolation - Over time the separated _________ can become so different that they may ____ be able to _____ __________ with each other anymore. The populations are now considered to be ___ ________ ______.
populations
NOT
mate
successfully
two
different
species

21. This example shows how the finches on the Galapagos Islands may have evolved.

22. Is there Evidence for Evolution?
Lots…..
fossil
genetic
biological

23. Fossil Evidence fossil record examining changed over time
The _____ ______ is all of the fossils that have been found.
By _________ the fossil record we can see what lived in the past.
Comparing organisms in the fossil record provides evidence for how organisms have ________________.
fossil
record
examining
changed over time

24. Do we have any fossil evidence for intermediate species.
Land Mammal ?
Do we have any fossil evidence for intermediate species.

25. All of these are intermediate species

26. Embryology – The study of early development in ________.
Biological Evidence
Embryology – The study of early development in ________.
organisms
During early __________, the embryos of a shark, a rabbit, and a gorilla look similar. This suggests an evolutionary __________ among all vertebrates.
development
relationship

27. Homologous Structures
Homologous Structures are similar structures with ________ functions.
different
The ____ ________ of the human arm, the front leg of a cat, the front flipper of a dolphin, and the wing of a bat are all ______.
bone
structure
similar

28. Vestigial Organs/Structures
Vestigial Organs show how some modern ________ are related to ancestors.
organisms
For Example: Whales have small ___ bones.
hip

29. Genetic Evidence comparing DNA similar related
Scientists can tell how closely organisms are related by ________ their ____.
The more ______ the DNA, the more closely ______ the organisms are (possibly evolved from common ancestor).
comparing
DNA
similar
related

30. How do we show evolutionary relationships?
Use ________ _______ to show how organisms are related.
branching
diagrams
Branching diagrams (cladograms) show which _____________ organisms _____ and when these organisms ______.
characteristics
share
evolved

31. These are the derived characteristics
Organisms are _______ in the diagram by their ______ _______ _____________.
grouped
shared
derived
characteristics
Derived characteristic: a ____ that two or more kinds of _________ _____ with their most recent common ________.
trait
organisms
share
ancestor
These are the derived characteristics

32. more characteristics more related
The ____ derived ____________ organisms share, the ____ closely ______ the organisms probably are.
more
characteristics
more
related
The house cat is more closely related to the lion because they have the most characteristics in common (having hair, mammary glands, birthing live young & retractable claws).

33. shared organisms above
Each characteristic listed on the diagram is only ______ by the ________ _____ it.
shared
organisms
above
The Brown bear has the characteristics of hair, mammary glands & birthing live young. It does not have retractable claws and the ability to purr. These characteristics are listed above the Brown bear in the diagram, therefore it does not have them.

34. Characteristics shown _____ on the _______ are more _____ than the characteristics below them.
higher
diagram
recent
The ability to purr is listed highest (or last) on the diagram This means it is the most recent characteristic to evolve and only the house cat has it.
most recent
The characteristic of having hair & mammary glands is listed first on the diagram. This means it evolved first, or it is the oldest characteristic in the diagram. All organisms in the diagram have this characteristic.
oldest