Presentation is loading. Please wait.

Presentation is loading. Please wait.

The History of Evolution

Similar presentations

Presentation on theme: "The History of Evolution"— Presentation transcript:

1 The History of Evolution
Darwin Lamarck

2 What is a Theory? Everyday Language Scientific Language Hunch; Guess
Created after years of experiments and observation Based on testable evidence Stood the test of time Based on gravitational theory, what do you think would happen if I dropped a pen?

3 #1: Isn’t Evolution Just A Theory?

4 Jean Baptiste de Lamarck
Acquired Inheritance: Early theory where changes acquired over a lifetime could be passed to offspring Ex: Evolution of the giraffe neck Short neck ancestors stretched their necks to reach leaves Stretched neck was passed to offspring Why this is wrong: Only traits linked to DNA can be passed to offspring

5 Silly Example of Acquired Inheritance
If Jacob has children in the future, how many arms will they have? Jacob lost his left arm Jacob is in a car crash Meet Jacob

6 Charles Darwin Observations:
Organisms have variations based on their environment Variations provide advantages Natural Selection: Process where organisms with favorable traits survive and reproduce 1859: Published The Origin of Species Notch in shell Survive in areas with higher vegetation No notch in shell Survive in areas with ground vegetation Those with short necks died. Those with longer necks survived and had babies. So how did giraffes get a long neck?

7 #2: Who Was Charles Darwin?

8 Adaptation vs. Variation
Variation: Inherited traits that make an individual different from others Ex: Galapagos finches vary in their beaks Adaptation: Variation that increases the chance of survival Ex: Which finch would be better adapted to an island with large seeds for food?

9 Butterflies won't lay eggs on plants with fake egg spots

10 Can you find the geckos?

11 Gross....bird poop...or is it???

12 Natural Selection in Action: The Peppered Moth Analysis
Before the industrial revolution, the trees in the forest around Manchester, England were a light grey/green due to the color of lichens (fungus) on their trunks.

13 Natural Selection in Action: The Peppered Moth Analysis
Peppered moths, or Biston betularia, which lived in the area were found in two varieties: 1) Light with dark spots (most common) and 2) Dark with light spots (less common).

14 Natural Selection in Action: The Peppered Moth Analysis
Because there were not enough resources to support the entire population, the two varieties of this species had to compete for survival. Their coloring, when against a similar background, served as camouflage against predators such as birds and lizards, thus increasing chances of survival.

15 Natural Selection in Action: The Peppered Moth Analysis
As the Industrial Revolution progressed, the trees became covered with sulfur dioxide, which killed the light colored lichen and thus turning the tree trunks dark.

16 Light peppered moth Dark peppered moth Year 1 Background Year 10 Background

17 Year 1: Peppered Moths Light 556 Dark 64

18 Year 10: Peppered Moths Light 56 Dark 638

19 Kobe Kuiz What is a theory?
What did acquired inheritance state and how was it thought to work? What does natural selection state and how is it thought to work? How does a variation and adaptation differ?

Download ppt "The History of Evolution"

Similar presentations

Ads by Google