WARM UP- Please get a white sheet from the tray on my stool- there is space for your warm up! IN YOUR OWN WORDS… 1.WHAT DOES ADAPTATION MEAN? 2.WHAT IS NATURAL SELECTION?

Evolution S7L5. Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring. a. Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwin’s finches and peppered moths of Manchester). What’s the Standard?

Charles Darwin: Who is this guy? Video Clip

Similarities and Differences Checkpoint: How did Darwin think plants and animals had originally come to the Galapagos Islands? Answer: Perhaps they had been blown out to sea or set adrift on a fallen log.

Adaptations What is an Adaptation? An adaptation is a trait that helps an organism adjust to its environment, survive and reproduce.

Adaptation: Elephant (Video Clip)

Adaptation: Giraffe Checkpoint: What type of adaptations allows giraffes to feed on a diet of leaves from treetops? (LEMARC– BEFORE DARWIN) Answer: The body structure of the giraffe has adapted over time.

Evolution What is Evolution? Darwin believed that species changed over time becoming better adapted to their environment. This process is slow and takes many generations.

Evolution What makes an idea a Theory? It is well tested and explains many observations. How does a Theory different from a fact? A fact is a specific observation, known to be true; a Theory is a broad concept, thought to be true because it explains many facts.

Natural Selection What is Natural Selection? Natural selection is the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species. Survival of the fittest! Who's Going to Survive?

Natural Selection Video Clip

Natural Selection There are several factors that Darwin identified that affect the process of natural selection: Overproduction of offspring Competition Variations

Overproduction Natural Selection Competition Variation

Overproduction Most species produce far more offspring than can possibly survive.

Competition Competition is the struggle between organisms for the limited resources in a habitat.

Variation Variation is any difference between individuals of the same species.

Natural Selection: Examples Are these two butterflies the same species? These are the Monarch and Viceroy butterflies. The Monarch on the left is poisonous and the Viceroy is not. Question: Why would it be beneficial for the Viceroy to look like the Monarch?

Natural Selection: Examples Checkpoint: A species of hare (rabbit) that is found in a cold tundra environment. How are oversized feet an advantage to the Arctic Hare?

Natural Selection: Examples How many moths do you see?

Warbler finch Woodpecker finch Small insectivorous tree finch Large insectivorous tree finch Vegetarian tree finch Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground finch Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Tree finches Ground finches variation natural selection for best survival & reproduction From 1 species to 14 species…

How Do New Species Form? A new species might form when a group of individuals remains separated from the rest of its species long enough to evolve different traits.

How Do New Species Form?

Have the Kaibab Squirrel and the Abert Squirrel been isolated long enough to become a new species?

An example of Evolution through Gene Flow

An example of Evolution through Genetic Drift