1. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
Arrange in order the 6 steps of Natural Selection:
Differential Reproduction,
Genetic Variation,
Survival of the Fit,
Accumulation of Traits,
Struggle for Survival, and
Overproduction 1. 2. 3. 4. 5. 6.
Genetic Variation
Overproduction
Struggle for Survival
Survival of the Fit
Differential Reproduction
Accumulation of Traits

2. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
2. Which are the steps of the Natural Selection mechanism shown in the pictures?
Genetic Variation
Struggle to Survival
or Survival of the Fit
Overproduction
Accumulation of traits
Differential Reproduction

3. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
3. Cockroaches that are resistant to many common house-hold insecticides are more numerous than those that are killed by the same insecticides.
First, arrange in order the step of Natural Selection. Then match each steps with its description.
Order
Step of Natural Selection
Description
Struggle to Survive
Cockroaches struggle to survive house-hold insecticides
Overproduction of Offspring
By reproduction, more organisms were produced that can survive
Genetic Variation
Those cockroaches with resistant-to- insecticides genes were better adapted to survive in the house. This is known as survival of the fit
Differential Reproduction
After many generations the favorable trait accumulated in the population. Eventually, organisms became resistant to the house-hold insecticide
Survival of the Fit
Not all of the cockroaches were identical. They had genetic variation. Some cockroaches had genes that made them resistant to house-hold insecticides and other did not have them
Accumulation of Traits
These cockroaches which survived, they reproduced and pass on the favorable variation – being able to survive the house-hold insecticide - to the next generation

4. Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction
Cockroaches that are resistant to many common house-hold insecticides are more numerous than those that are killed by the same insecticides. Explain how this can be possible.
1. GENETIC VARIATION
Not all of the cockroaches were identical. They had genetic variation. Some cockroaches had genes that made them resistant to house-hold insecticides and other did not have them.
2. OVERPRODUCTION OF OFFSPRING
By reproduction, more organisms were produced that can survive.
3. STRUGGLE TO SURVIVE
Cockroaches struggle to survive house-hold insecticides.
4. SURVIVAL OF THE FIT
Those cockroaches with resistant-to- insecticides genes were better adapted to survive in the house. This is known as survival of the fit.
5. DIFFERENTIAL REPRODUCTION
These cockroaches which survived, they reproduced and pass on the favorable variation – being able to survive the house-hold insecticide - to the next generation.
6. ACCUMULATION OF TRAITS
After many generations the favorable trait accumulated in the population. Eventually, organisms became resistant to the house-hold insecticide.

5. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
A population of mosquitoes is sprayed with a new insecticide. Most of the mosquitoes are killed, but a few survive. In the next generation, the spraying continues, but still more mosquitoes are immune to the insecticide. How could these results be explained?
1. GENETIC VARIATION (genetic variation, mosquitoes, resistant, insecticide, genes)
Not all of the __________________ were identical. They had ________________. Some _____________ had ____________ that made them __________ to _________________ and other did not have them.
2. OVERPRODUCTION OF OFFSPRING (survive, reproduction)
By ___________________, more ______________ were produced that can ______________.
3. STRUGGLE TO SURVIVE (natural resources, struggle, insecticide)
Mosquitoes _____________to survive _______________________.
genetic variation
mosquitoes
mosquitoes
genes
resistant
insecticides
reproduction
mosquitos
survive
struggle
insecticide

6. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
4. SURVIVAL OF THE FIT (survival of the fit, adapted, insecticide, mosquitoes) Those ______________ with resistant-to- _______________ genes were better _________ to survive____________. This is known as ____________________ 5. DIFFERENTIAL REPRODUCTION (pass, reproduce, mosquitoes, being resistant to insecticide) These ______________which survived, they ____________ and ________ on the favorable variation – _________________________ - to the next generation. 6. ACCUMULATION OF TRAITS (resistant, accumulated, insecticide, natural selection) After many generations, the favorable trait _____________________ in the population. Eventually, organisms became ______________________ to the _________________. This process is known as ______________________________
mosquitoes
insecticide
adapted
insecticide
survival of the fit
mosquitoes
reproduce
pass
being resistant to insecticide
accumulated
resistant
insecticide
Natural Selection

7. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
August’01. (69)
A European species of rabbit was released on a ranch in Victoria, Australia. The species thrived and reproduced rapidly. The rabbits overgrazed the land, reducing the food supply for the sheep. The Myxoma sp. Virus was used to kill the rabbits. The first time this virus was applied, it killed 99.8% of the rabbits. When the rabbits became a problem again, the virus was applied a second time. This time, only 90% of the rabbits were killed. When the rabbits became a problem a third time, the virus was applied one again, and only 50% of the rabbits were killed. Today, this virus has little or no effect on this species of rabbit.
Explain what happened to the species of rabbit as a result of the use of this virus. You must include and circle the following terms in your answer: gene, adaptive value or adaptation or adapted, variation, survival of the fittest.

8. How Does Natural Selection Really Work?
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
How Does Natural Selection Really Work?
1. GENETIC VARIATION Not all of the rabbits were identical. They had genetic variation. Some rabbits had genes that made them resistant to Myxoma virus and other did not have them.
2. OVERPRODUCTION OF OFFSPRING By reproduction, more rabbits were produced that can survive.
3. STRUGGLE TO SURVIVE Rabbits struggle to survive the Myxoma virus.
4. SURVIVAL OF THE FITTEST
Those rabbits with resistant-to-Myxoma-virus genes were better adapted to survive. This is known as survival of the fit
5. DIFFERENTIAL REPRODUCTION
These rabbits which survived, they reproduce and pass on the favorable variation – being resistant to Myxoma virus- to the next generation
6. ACCUMULATION OF TRAITS
After many generations the favorable trait – being resistant to Myxoma virus- accumulated in the population. Eventually, organisms became resistant to Myxoma virus.
This process is known as natural selection.

9. Objective: Understand Why Evolution Matters Now Key Words: Resistance, Tuberculosis, Antibiotics, Natural Selection
Learn how tuberculosis is transmitted and why the evolution of multi-drug resistant strains of TB in Russia affects us all

10. 3. STRUGGLE TO SURVIVE Bacteria struggle to survive antibiotics.
Objective: Understand Why Evolution Matters Now Key Words: Resistance, Tuberculosis, Antibiotics, Natural Selection
Jan’02 (68) In the past, a specific antibiotic was effective in killing a certain species of bacteria. Now, most members of this bacterial species are resistant to this antibiotic.
Explain how this species of bacteria has become resistant. Your answer must include at least the concepts of: Overproduction variation natural selection adaptation to the environment.
1. GENETIC VARIATION Not all of the bacteria were identical. They had genetic variation. Some bacteria had genes that made them resistant to antibiotics and other did not have them.
2. OVERPRODUCTION OF OFFSPRING By reproduction, more bacteria were produced that can survive.
3. STRUGGLE TO SURVIVE Bacteria struggle to survive antibiotics.

11. Objective: Understand Why Evolution Matters Now Key Words: Resistance, Tuberculosis, Antibiotics, Natural Selection
Jan’02 (68) In the past, a specific antibiotic was effective in killing a certain species of bacteria. Now, most members of this bacterial species are resistant to this antibiotic. Explain how this species of bacteria has become resistant. Your answer must include at least the concepts of:
Overproduction variation natural selection adaptation to the environment.
4. SURVIVAL OF THE FITTEST
Those bacteria with resistant-to- antibiotics genes were better adapted to survive. This is known as survival of the fit
5. DIFFERENTIAL REPRODUCTION
These bacteria which survived, they reproduce and pass on the favorable variation – being resistant to antibiotics - to the next generation
6. ACCUMULATION OF TRAITS
After many generations, the favorable trait accumulates in the population. Eventually, bacteria became resistant to antibiotics
This processs is know as Natural Selection

12. Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
Use the terms gene, variation, adaptation, and survival of the fittest to explain the evolution of resistance to a virus in gerbils.
Your explanation should be in accordance with the theory of natural selection.
1. GENETIC VARIATION Not all of the gerbils were identical. They had genetic variation. A few gerbils had genes that made them resistant to a virus and most of them did not have them.
2. OVERPRODUCTION OF OFFSPRING By reproduction, more gerbils were produced that can survive.
3. STRUGGLE TO SURVIVE Natural resources were limited. Gerbils struggle to survive virus.

13. 4. SURVIVAL OF THE FITTEST
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
Use the terms gene, variation, adaptation, and survival of the fittest to explain the evolution of resistance to a virus in gerbils.
Your explanation should be in accordance with the theory of natural selection.
4. SURVIVAL OF THE FITTEST
Those gerbils with resistant-to- virus genes were better adapted to survive. This is known as survival of the fit
5. DIFFERENTIAL REPRODUCTION
These gerbils which survived, they reproduce and pass on the favorable variation – to be resistant to virus - to the next generation
6. ACCUMULATION OF TRAITS
After many generations, the favorable trait accumulates in the population. Eventually, gerbils became resistant to virus.
This is known as natural selection

14. 3. STRUGGLE TO SURVIVE Bacteria struggle to survive penicillin.
Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
Some bacteria have become resistant to penicillin by producing an enzyme called penicillinase to destroy this antibiotic.
In an essay, explain one mechanism of these bacteria developing resistant.
Include the terms variation, adaptation, natural selection, resistance, gene, and survival of the fittest.
1. GENETIC VARIATION Not all of the bacteria were identical. They had genetic variation. Some bacteria had genes that made them resistant to penicillin and other did not have them.
2. OVERPRODUCTION OF OFFSPRING By reproduction, more organisms were produced that can survive.
3. STRUGGLE TO SURVIVE Bacteria struggle to survive penicillin.

15. Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
Some bacteria have become resistant to penicillin by producing an enzyme called penicillinase to destroy this antibiotic.
In an essay, explain one mechanism of these bacteria developing resistant.
Include the terms variation, adaptation, natural selection, resistance, gene, and survival of the fittest.
4. SURVIVAL OF THE FITTEST
Those bacteria with resistant-to- penicillin genes were better adapted to survive. This is known as survival of the fit
5. DIFFERENTIAL REPRODUCTION
These bacteria which survived, they reproduce and pass on the favorable variation – being resistant to penicillin - to the next generation
6. ACCUMULATION OF TRAITS
After many generations, the favorable trait accumulates in the population. Eventually, bacteria became resistant to penicillin.
This process is known as Natural Selection.

16. Growers of fruit trees have always had problems with insects
Growers of fruit trees have always had problems with insects. Insects can cause visible damage to fruits, making them less appealing to consumers. As a result of this damage, much of the fruit cannot be sold. Insecticides have been useful fro the controlling theses insects, but in recent years, some insecticides have been much less effective. In same cases, insecticides do nothing to stop the insect attacks.
Provide a biological explanation for this loss of effectiveness of the insecticide. In your answer, be sure to:
a. Identify the original event that resulted in the evolution of insecticide resistance in some insects.
__________________________________________________________________
b. Explain why the percentage of resistant insects in the population has increased. You must include and circle the following terms in your answer: gene, adaptive value or adaptation or adapted, variation, survival of the fittest.

17. 6. A scientist discovered that in a large population of E
6. A scientist discovered that in a large population of E.coli bacteria, a few were resistant to the antibiotic streptomycin. By adding streptomycin to the population, she soon obtained a large population that was resistant to streptomycin.   A. Explain how this experiment supports the concept of evolution by natural selection. Your explanation should include the concepts of Selective agent Resistance Reproduction Offspring   b. Identify the chemical substance in the bacteria that provides the resistance to streptomycin and makes this resistance inheritable.   C. The evolutionary changes described here occurred in a relatively short period of time rather than requiring millions of years. State one reason why it is possible for E.coli to evolves so rapidly.

18. antibiotic streptomycin
E. Coli bacteria
genetic variation
genes
bacteria
antibiotic streptomycin
survive
reproduction
bacteria
antibiotic streptomycin
Natural resources
Bacteria
struggle
___________________
antibiotic streptomycin
adapted
survival of the fit

19. be resistant to antibiotic
insecticide
bacteria
adapted
survival of the fit
antibiotic
bacteria
reproduced
passed
be resistant to antibiotic
accumulates
Resistant to antibiotic streptomycin.
Natural selection
This process is known as ______________________________

20. b. Identify the chemical substance in the bacteria that provides the resistance to streptomycin and makes this resistance inheritable.  
C. The evolutionary changes described here occurred in a relatively short period of time rather than requiring millions of years. State one reason why it is possible for E.coli to evolves so rapidly

21. Jan’03 (70) Over the last 30 years, a part of the Hudson River known as Foundry Cove has been the site for many factories that have dumped toxic chemicals into the river. Some of these pollutants have accumulated in the mud at the bottom of the river. The polluted cove water contains many single-celled organisms and simple multi-cellular animals. Curiously, when the same species from nearby regions with non-polluted sediments are moved to the polluted cove water, they die.
Scientists hypothesized that the organisms living in the cove have evolved so that they are able to survive in polluted water. To test this hypothesis, biologists tried to duplicate the history of the cove in the laboratory.
They took a large number of one species of simple animal from a cove with unpolluted mud and placed them in a flask that contained polluted mud from Foundry Cove (diagram 1).
Most of the animals died, but a few survived (diagram 2).
The scientists then bred the survivors with each other for several generations producing offspring that were descendants of the survivors. When placed in Foundry Cove, most of these descendants survived.
The diagrams below represent the steps in this investigation

22. Environment genetic variation selection reproduction
On the diagram of the flask below, sketch the animals that would be present in flask 3 after several generations of breeding in the laboratory.
Explain how the simple animals of Foundry Cove adapted to the polluted water. Your answer must include an explanation of the role of three of the following in this process.
Environment genetic variation selection reproduction
survival of the fittest

23. Objective: Understand How the Mechanism of Natural Selection Explains Evolution Key Words: Genetic Variation, Competition, Overproduction, Survival of the Fit, Differential Reproduction, Accumulation of Traits
DO NOW: Do you agree or disagree with the vignette? Explain.