Natural Selection

Objective: SWBAT Analyze animal adaptations and the effects of natural selection with examples in order to explain the term “survival of the fittest” and natural selection as the central idea of Darwinian Evolution

IntroductionDescribe what is happening in figures 1-3. Is

the population of mice different in figure 3 than in figure 1? Explain why.

Notes – Right Page

Living things that are well adapted to their environment survive and reproduce. Those that are not well adapted don’t survive and reproduce. An ___________ is any characteristic that increases ________, which is defined as the ability to survive and reproduce. What characteristic of the mice is an adaptation that increased their fitness?

adaptation

fitness

Notes – Right Page

Natural Selection: 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

Natural Selection = ENVIRONMENT CHOOSES

Natural Selection Activity

Table 1: “Mouse Cards”

Number Label Meaning

25 W Dominant allele for white fur

25 w Recessive allele for brown fur

Table 2: “Event Cards”Number Label Meaning

5 S Mouse Survives

1 D Disease kills mouse

1 PPredator kills

mice of all colors

18 C

Predator kills mice that

contrasts with the

environment

Activity

Live Mice Dead Mice

Mouse Event

MouseMouse

wWWhat color is the mouse’s fur? White

Environment 1: White Sand Environment

Event C

Does the mouse live or die?Lives because it can blend in with the white sand environment. Place Mouse cards in “Live Mice” pile to use for generation 2.

wW

Data TableType of Environment:

Generation White Mice Brown Mice

Deaths

White Mice Brown Mice

1

2

3

White Sand

Activity

Live Mice Dead Mice

Mouse Event

MouseMouse

wwWhat color is the mouse’s fur? Brown

Environment 1: White Sand Environment

Event C

Does the mouse live or die?Dies because it does not blend in with the white sand environment. Place Mouse cards in “Dead Mice” pile and DO NOT reuse these cards for generation 2 and 3.

ww

Data TableType of Environment:

Generation White Mice Brown Mice

Deaths

White Mice Brown Mice

1

2

3

White Sand

Activity

Live Mice Dead Mice

Mouse Event

MouseMouse

wwWhat color is the mouse’s fur? Brown

Environment 1: White Sand Environment

Event S

Does the mouse live or die?Lives even though its fur is in contrast with the environment, the EVENT card says that it survives.

ww

Data TableType of Environment:

Generation White Mice Brown Mice

Deaths

White Mice Brown Mice

1

2

3

White Sand

Activity

• Part 1: White Sand Environment (White)– Complete “Mouse” Cards pile First generation– Take all cards from “Live Mice,” shuffle and repeat

activity for generations 2 & 3– DO NOT use cards in Dead Mice pile (they are not

able to reproduce for future generations– Correctly fill out Data Table in Interactive Notebook

• Part 2: Forest Floor Environment (Brown)– Repeat activity but change the environment– Correctly fill out Data Table in Interactive Notebook

Activity

Live Mice Dead Mice

Mouse Event

MouseMouse

wwWhat color is the mouse’s fur? Brown

Environment 2: Forest Floor Environment

Event C

Does the mouse live or die?Lives because it can blend in with the forest floor environment. Place Mouse cards in “Live Mice” pile to use for generation 2.

ww

Data TableType of Environment:

Generation White Mice Brown Mice

Deaths

White Mice Brown Mice

1

2

3

Forest Floor

Analyze and Conclude• Answer Questions

– With group, complete answers #1-5 on LEFT side of Interactive Notebook

Exit Ticket• Turn in on a separate sheet of paper a 25 Word

SummaryExplain how natural selection leads to evolution.

_______ _______ _______ _______ ______________ _______ _______ _______ ______________ _______ _______ _______ ______________ _______ _______ _______ ______________ _______ _______ _______ _______