1. The Evolution of Living Things
Chapter 5

2. Change over Time Section 1 Vocabulary Adaptation Species Evolution
Fossil
Fossil Record

3. Differences Among Organisms
Each frog has a different characteristics that might help the frog to survive.
Adaptation
Physical-long neck
Behaviors- protect itself
Living things that have the same characteristics may be members of the same species.
Can mate with one another to produce fertile offspring
Groups of individuals of the same species living in the same place make up the population.

4. Do Species Change over Time?
Millions of different species of organisms
Range from single celled bacteria to multicellular fungi, plants, and animals
4.5 billion years old
Many species have died out
Many new species have appeared
Inherited characteristics in populations change over time
As populations change- new species form
Newer species descend from older species
Evolution

5. Evidence of Changes over Time
Evidence that evolution has happened is buried within Earth.
Arranged in layers
Layers-made of different kinds of rocks and soil stacked on top of each other
Sediments-particles of sand, dust, or soil are carried by the wind and water and are deposited

6. Fossils
The remains or imprints of once living organisms are found in the layers of rocks
Fossils-complete organisms, parts of organisms, set of footprints
Formed when a dead organism is covered by a layer of sediment
Minerals may seep into the organism and gradually replace the organism with stone
If it rots away completely after being covered, it may leave an imprint of itself in the rock.

7. The Fossil Record Fossil Record
Organizes fossils by their estimated ages and physical similarities
Newer layers-similar to present-day organisms
Close relatives of present-day organisms
Older layers-less similar to present-day organisms
Earlier life-forms
May not exist anymore

8. Evidence of Ancestry
Fossil record provides evidence about the order in which species have existed
Observe all living things-common characteristics
Come from common ancestors

9. Drawing Connections
Examine the fossil record to figure out the relationship between extinct and living organisms
Draw maps
Branch- represents a group of organisms that descended from a species

10. Drawing Conclusions
Whales and some types of hoofed mammals have a common ancestor
Lived between 50 million and 70 million
Dinosaurs died out and a variety of mammals appeared in the fossil record
Ocean Dwelling mammals- 50 millions years ago
All mammal species alive toady evolved from common ancestors

11. Drawing Conclusions
Named and described hundreds of thousands of living and ancient species
“Tree of Life”
Includes all known organisms
Information is incomplete
Lack parts of fossil record
Fossils are rare because specific conditions are necessary for fossils to form

12. Disney “Tree of Life”

13. Examining Organisms
Examining an organisms carefully can give scientists clues about its ancestors.
Whales similar to fish
Whales- mammals
Breathe air
Give birth to live young
Produce milk
Evolved from ancient mammals

14. Case Study: Evolution of Whale
Whale Ancestor
Mammal
Lived on land
Run on four legs
More recent ancestor
Spent time both on land and water
Comparisons of modern whales and a large number of fossils have supported this hypothesis

15. Walking Whales
Several pieces of evidence show that they are related by ancestry
Share traits
Some species have new traits that were shared with later species
Modern whales-no hind legs
Have tiny hip bones
Inherited from the whales’ 4 legged ancestors

16. Comparing Organisms
Evidence that groups of organisms have common ancestry can be found by comparing the group’s DNA.
Every organism inherits the traits determined by DNA
Species undergo changes in traits and DNA over time

17. Comparing Skeletal Structures
Similarities in the bone structure
Cat
Dolphin flipper
Bat wing
Human arm
Had a common ancestor
Changes occurred in the limb bones of the ancestor’s descendants
Perform different functions in each type of animal

18. Comparing DNA DNA of a house cat is similar to the DNA of a tiger
Traits are inherited through DNA’s genetic code
If species that have similar traits evolved from a common ancestor, the species will have similar genetic information.
The fact that all existing species have DNA support the theory that all species share a common ancestor

19. How Does Evolution Happen?
Section 2 Vocabulary
Trait
Selective Breeding
Natural Selection

20. Charles Darwin Darwin graduated and did not know what to do.
Interested in the study of plants and animals
5 year voyage around the world
Naturalist-studies nature
Made observations that helped him form a theory about how evolution happens

21. Darwin’s Excellent Adventure
Beagle’s journey
Collected thousands of plants and animal samples
Kept careful notes of his observations
Galapagos Island
West of Ecuador
South America

22. Darwin’s Finches
Animals and plants were similar to the plants and animals in Ecuador
Not exactly the same
Finches on each island were different
The beak of each finch is adapted to the way the bird usually gets his food

23. Darwin’s Thinking
Tried to explain why the animals seemed so similar to each other yet had so many different adaptations
Hypothesized that the island finches were descended from S.A. finches
May have been blown from SA by a storm
Adapted to different ways of life on the island

24. Ideas About Breeding
Farmers and breeders had produced many kinds of farm animals and plants
Traits that were desired
Selective Breeding
Dogs have been bred for various desired traits
Horses-strong and fast
Crops-large fruit specific climates

25. Ideas About Population
Thomas Malthus-An Essay on the Principle of Population
Humans have the potential to reproduce rapidly
Warned that food supplies could not support unlimited population growth
Limited by choices that humans make or by problems such as starvation and disease
Darwin-and species can produce many offspring
Limited by same things
Limited number of individuals survive to reproduce
Inherited traits help offspring survive in their environment

26. Idea’s About Earth’s History
Most did not think that Earth was old enough to allow for slow changes
Principals of Geology
Charles Lyell
Presented evidence that Earth formed by natural processes over a long period of time
Earth is much older than they thought

27. Darwin’s Theory Struggled with his idea for 20 years
1858-received a letter from a fellow naturalist, Alfred Russel Wallace
Same idea about evolution
1859-published On the Origin of Species by Means of Natural Selection
Evolution happens through a process called natural selection

28. Genetics and Evolution
Lacked evidence for parts of his theory
he knew that they inherited traits but did not know how
Knew their were great variations among species but did not know it occurred
They now know it comes from genes
Some genes make an organism more likely to survive to reproduce- selection
Only happens when organisms that carry these genes can survive to reproduce

29. Natural Selection in Action
Section 3 Vocabulary
Generation Time
Speciation

30. Natural Selection in Action
A population of bacteria might develop an adaptation through natural selection.
Most killed by chemicals in antibiotics
Some naturally resistant- not killed
Then pass of their resistance to their offspring

31. Changes in Populations
Natural Selection- explains how a population changes in response to its environment
If it is happening all the time- a population will tend to be well adapted to its environment
Well adapted-more likely to survive and reproduce

32. Adaptation to Hunting
Observed when a new force affects the survival of individuals
Elephants
Hunt elephants with tusks
More tuskless elephants are around
Tuskless elephants are able to survive and reproduce

33. Insecticide Resistance
Want to control the insect populations around their homes and farms
Insecticides
Used to work well do not anymore
Resistant to common insecticides
500 kinds are now resistant
Produce many offspring and have short generation times
Generation time

34. Competition for Mates Survival is simply not enough
Natural selection- individuals reproduce
Organisms that reproduce sexually-finding a mate is part of the struggle to reproduce
Interesting adaptations can result
Female birds prefer males that have certain types of colors

35. Forming a New Species
Drastic changes that can form a new species take place
New species may form after a group becomes separated from the original population
New population
They adapt to their new environment
Become so different they can not mate anymore- new species
Speciation- finches

36. Separation Part of a population becomes separated from the rest
Can happen in many ways
Examples
Newly formed canyon
Mountains range
Lake
Can divide the members of a population