Requirements for Natural Selection

Requirements for Natural Selection

Why don't all populations change over time?

Review- Traits

• Organisms pass down their traits to their offspring.

• We also say, organisms inherit traits from their biological parents.

• An organism's traits affects whether it can meet its needs.

• Traits can be classified into helpful, harmful, or neutral, depending on the organism's habitat.

Multiple Choice

Organisms ____ their traits from their parents.

• Behavior

• Trait

• Inherit

• Organism

Multiple Choice

Organisms inherit their _____ from their parents.

• Behaviors

• Traits

Multiple Choice

Offspring inherit their traits from their biological parents.

We can also say parents ____ their traits to their offspring.

• lose
• pass down
• give away
• hand over

Match

Match the vocab word to its definition.

• Makes it easier to meet its needs

• Makes it harder to meet its needs

• Doesn't affect if an organism can meet its needs

Helpful

Harmful

Neutral

• Helpful

• Harmful

• Neutral

Multiple Choice

Whether a trait is helpful, harmful, or neutral will depend on an organism's ___.

• favorite things

• habitat

• age

• religion

Open Ended

"One trait that would be helpful here is ____, because ____.

One trait that would be harmful here is ____, because ____."

Changing Traits

• An individual is one organism.

  An individual cannot change its traits

• A population is a group of organisms that live in one place.

• Traits change in a population, based on which organisms reproduce.

Multiple Choice

What do we call one organism?

• An individual

• A population

• A species

Multiple Choice

What do we call a group of organisms that live in one place?

• An individual

• A population

• A species

Dropdown

The traits of a ​

Select answer

CANNOT change,

but the traits of a ​

Select answer

can change.

Multiple Choice

Traits in a population will change when ___.

• Only some organisms survive and pass on their traits.

• The individuals decide to look different.

• Every organism survives and passes on its traits.

Multiple Choice

A population has some green organisms and some brown organisms.

The brown organisms hide in the mud, but the green ones get eaten.

In the future, there will be more ____ organisms.

• Green

• Brown

Multiple Choice

Why will there be more brown organisms?

• The green organisms died before they reproduced

• The green organisms turned brown

Requirements for Changing Traits

• Variation - Organisms must have different traits.

• Inheritance - Organisms pass down their traits to their offspring.

• Selection - One trait must help some organisms survive long enough to reproduce.

• Adaptation - Over time, the population changes.

Multiple Choice

Organisms have different traits.

• Adaptation

• Selection

• Variation

• Inheritance

Multiple Choice

Traits are passed down from parents to offspring.

• Adaptation

• Selection

• Variation

• Inheritance

Multiple Choice

More organisms with that trait survive and reproduce.

• Adaptation

• Selection

• Variation

• Inheritance

Multiple Choice

A population changes to share the helpful trait.

• Adaptation

• Selection

• Variation

• Inheritance

Match

Match the requirement to its definition.

• Organisms have different traits.

• Traits are passed down from parents to offspring.

• More organisms with the helpful trait survive, and organisms with the harmful trait die.

• The population changes to share the helpful trait.

Variation

Inheritance

Selection

Adaptation

• Variation

• Inheritance

• Selection

• Adaptation

Multiple Choice

Katydids can be green or pink.

• Selection

• Variation

• Adaptation

• Inheritance

Multiple Choice

Green katydids have green offspring.

Pink katydids have pink offspring.

• Selection

• Variation

• Adaptation

• Inheritance

Multiple Choice

Green katydids camouflage.

Pink ones get eaten before they reproduce.

• Selection

• Variation

• Adaptation

• Inheritance

Multiple Choice

Eventually, the population has only green katydids.

• Selection

• Variation

• Adaptation

• Inheritance

Match

Match the requirement to the example.

• Bears can be born with brown or white fur.

• Parents with brown fur have offspring with brown fur.

• Bears with white fur can meet their need for food. Bears with brown fur starve to death.

• In the future, more bears have white fur than brown fur.

Variation

Inheritance

Selection

Adaptation

• Variation

• Inheritance

• Selection

• Adaptation

Match

Match the requirement to the example.

• Pelicans can be born with thin beaks or deep beaks.

• Parents with deep beaks have offspring with deep beaks.

• Pelicans with deep beaks can meet their need for food.

  Pelicans with thin beaks starve to death.

• In the future, more pelicans have deep beaks than thin beaks.

Variation

Inheritance

Selection

Adaptation

• Variation

• Inheritance

• Selection

• Adaptation

Multiple Choice

When snakes with brown spots reproduce, some offspring have brown spots and some do not.

The population does not change over time.

Which requirement is missing?

• Variation

• Inheritance

• Selection

Multiple Choice

Every flamingo on this island has pink feathers.

The population does not change over time.

Which requirement is missing?

• Variation

• Inheritance

• Selection

Multiple Choice

There is enough food in the zoo exhibit that every zebra survives, no matter how many stripes it has.

The population does not change over time.

Which requirement is missing?

• Variation

• Inheritance

• Selection

Open Ended

1. Describe how a population of giraffes could change from a mix of short and long necks to all long necks.

2. "Variation: The organisms have different _____________.

3. Inheritance: We know this trait is inherited because organisms with _______ gave birth to offspring with ___________. 

4. Selection: Individuals with _______ survive because ______________________. 

5. Adaptation: Eventually, all the organisms in the population have _______________. "