1. Change over Time Adaptation
a characteristic that helps an organism survive in its environment
Two types of adaptations
Structural – physical feature
Ex. Long neck, gills, striped fur
Behavioral – action of organism
Ex. Hibernation, hunting at night

2. Great Blue Heron Adaptations
The Great Blue heron has adapted in many ways.
They have mastered the art of hunting by standing still in shallow water waiting for their prey, then stabbing it with their extremely sharp beak.
In addition, they adapted to avoid predators by building their large nests of sticks in trees so they cannot be reached easily by most predators.
Lastly, it adapted to its environment by getting a grey-blue camouflage and a streaked white neck to blend in with its surroundings.

3. Amur Tiger Adaptations
Characteristics that improves an individual’s ability to survive and reproduce in a particular environment.

5. Species
A group of organisms that can mate with one another to produce fertile offspring
Scientists believe that as Earth changes species also change or
Species die out
New species appear

6. Scientists observe that species change over time
Evolution
The process in which populations gradually change over time
Evolution happens by Natural Selection
the process of sorting individuals based on their ability to survive and reproduce within their ecosystem.

7. THE PRINCIPLES OF NATURAL SELECTION
Organisms produce more offspring that can survive.
Differences, or variations, occur among individuals of a
species.
Some variations are passed to offspring. (Every individual has its own combination of traits so it is similar to, but not identical to, its parents.)
Some variations are helpful. Individuals with helpful
variations survive and reproduce better than those without these variations.
Over time, the offspring of individuals with helpful
variations make up more of a population and eventually may become a separate species.
THE PRINCIPLES OF NATURAL SELECTION
Organisms produce more offspring that can survive.
Differences, or variations, occur among individuals of a
species.
Some variations are passed to offspring. (Every individual has its own combination of traits so it is similar to, but not identical to, its parents.)
Some variations are helpful. Individuals with helpful
variations survive and reproduce better than those without these variations.
What might happen to an
albino lemur in its natural
environment?

8. Examples of Natural Selection in Action – Changes in Populations
Insecticide Resistance
A few insects in a population may be naturally resistant to a chemical insecticide. These insects pass their resistance trait to their offspring, and an insect population gradually becomes resistant to the insecticide.
Adaptation to Hunting People hunt elephants for their tusks. As a result, fewer of the elephants that have tusks survive to reproduce, and more of the tuskless elephants survive.
Competition for Mates Many species have so much competition for mates that interesting adaptations result. For example, the females of many bird species prefer to mate with males that have colorful feathers.

9. Darwin’s Finches Darwin noticed that the finches of the Galápagos Islands were a little different from the finches in Ecuador. And the finches on each island differed from the finches on the other islands.

10. Natural Selection in Action - The Process of Speciation
Separation Speciation often begins when a part of a population becomes separated from the rest.
Adaptation Populations constantly undergo natural selection. After two groups have separated, natural selection may act on each group in different ways.
Division Over many generations, two separated groups of a population may become very different until the point when they can no longer mate with one another. At this point, the two groups are no longer the same species.

12. Evidence of changes Fossils
The remains or imprints of once-living organisms found in layers of rock
Fossil record
Timeline of when certain organisms existed
Made by studying fossils embedded in rock
Evidence #1:
Fossils in newer rock layers more similar to organisms today
Older fossils less similar to today’s organisms
Part of fossil record is missing
Fossils are rare – few organisms will become fossils

13. ..

14. Evidence #2:
Many organisms have common characteristics (bone structure, development in womb)
This indicates organisms have common ancestors

15. Evidence: Case Study = Whale
Evidence in fossils links whales to mammals that lived on land To
Organisms that partly lived on water and partly on land
An organism that lived in water
Modern day whales

16. Scientists think that the ancient ancestor of whales was probably a mammal that lived on land and that could run on four legs. The organisms shown form a sequence between ancient four-legged mammals and modern whales. Several pieces of evidence indicate that these species are related by ancestry

17. Evidence in skeletal structure of today’s whale
Whales have hip bones!!
(whales do not walk)

18. When comparing organisms:
Evidence found :
In skeletal structures
Structures and order of bones are similar in organisms
Evidence #3: When comparing DNA
DNA in living organisms are similar
More closely related organisms have a greater amount of DNA in common
(chickens and dinosaurs)