CATALSYT

• What key ingredients are needed for life?

• Where do we think these ingredients may have come from in early earth?

• Outline three lines of evidence for the theory of endosymbiosis.

TODAY: THE BIRTH OF EVOLUTIONARY THEORY!

…brought to you by…Charles Darwin

TODAY: THE BIRTH OF EVOLUTIONARY THEORY!

…and Darwin Hines

BEFORE DARWIN….

1) All species are independent

2) Life on earth is young ~6,000 years old

3) Species are immutable

HOW DO WE GET TO THE THEORY OF EVOLUTION ?

1) Lyell 2) Malthus 3) Lamark4) Wallace5) Darwin

What are they saying? How might they have influenced Darwin?

What is he saying? How is he saying it? Why do you think he opened his book in this manner?

“Darwin’s Dangerous Idea”

What evidence does Darwin examine?

What smaller “revelations” lead to the development of his larger theory?

Darwin’s Theory of Evolution By Natural Selection:

1. Variation

Cepaea nemoralis Banded snail

Darwin’s Theory of Evolution By Natural Selection:

2. Overpopulation

Darwin’s Theory of Evolution By Natural Selection:

3. Natural Selection

Darwin’s Theory of Evolution By Natural Selection:

4. Inherited

In your words…Explain the change in one of the following species over time using Darwin’s Theory of Natural Selection:

Lepus arcticusArctic hare

Lepus californicusJack rabbit

In your words…Explain the change in one of the following species over time using Darwin’s Theory of Natural Selection:

Fennec fox

Arctic fox

Natural Selection’s Results

1.

2.

3.

Stabilizing Selection

Directional Selection

Directional Selection

Peppered moth

Directional Selection

Peppered moth

Disruptive Selection

Practice Making Predictions!The Venus fly trap is famous for its ability to trap and devour flies. However, very small flies or very large flies are often able to escape. How would you predict the phenotypic distribution of the fly population to change over time?

Type of Selection?

Changes in Phenotypic Distribution?

Practice Making Predictions!Some strains of Neisseria gonorrhoeae bacteria have acquired genes for multiple resistance to antibiotics. Assuming these antibiotics continue to be used, how would you predict the relative frequency of antibiotic resistance amongst the bacteria to change?

Type of Selection?

Changes in Phenotypic Distribution?

Your Turn!Imagine a new selective pressure on the human population. Describe the selective pressure below. As a class, we will guess the type of selection and the expected changes to the

phenotypic distribution of the population.

Sickle Cell AnemiaType of Selection?

Explanation: