ecosystems and natural selection

APEX BIOLOGY - QTR. 3 Submit only this page for grading. Packet # 8 of 14

March 1-5, 2021 Barton, Somosa, Yonnie 1

3 Unit Overview: Ecosystems and Natural Selection 3.3 Adaptation and Natural Selection

3.3.1 Variation & Adaptation: Study 3.3.2 Variation & Adaptation: Lesson QUIZ Scoring: 20 points 3.3.3 Natural Selection: Study 3.3.4 Natural Selection: Lesson QUIZ Scoring: 20 points

3.4 Ecosystems and Natural Slection

3.4.1 Natural Selection: Study 3.4.2 Natural Selection: Lesson QUIZ Scoring: 20 points

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Instructions:

Students please annotate, by highlighting or underlining, words or sentences in the Study sections to show that you have read and studied the study sections prior to taking the quizzes.

Adaptation and Natural Selection What is the "survival of the fittest"? And who is "the fittest"? Time to learn about natural selection, which will introduce you to the theory of evolution. You're about to see how what you've learned about population structure, dynamics, and genetics connects to understanding which organisms are "the fittest." Objectives:

• Describe the difference between adapting and an adaptation.

• Explain the importance of genetic diversity in a population.

• Describe what makes one organism more fit than another.

• Explain natural selection

3.3.1 Study: Variation and Adaptation

Charles Darwin began his studies in the Galápagos Islands. Depending on which scientist you talk to, you'd hear that there are anywhere from 5 million to 30 million different kinds of organisms on the Earth. But you probably won't find 5 million different kinds of organisms in your backyard, in the river in your area, or even in a tropical forest. So why don't the same organisms live everywhere?

The Galápagos Islands. Charles Darwin was one of the first scientists to try to explain the great variation of organisms on Earth, and why different organisms live in different places. Charles Darwin was an Englishman who, when he was 22, decided to take a five-year voyage on the ship the HMS Beagle. The ship sailed to many parts of the globe, including the Galápagos Islands off Ecuador, on the western side of South America.

Variation in the Galápagos

The Galápagos Islands contain a lot of variation in species. The Galápagos Islands have many species of animals that are found in no other place in the world. Differing Organisms

Different organisms have different traits based on their DNA.

Of particular interest to Darwin were the finches that lived in the Galápagos. Darwin noticed that each type of finch had a different beak. Finches that ate different foods had different beak shapes. Although the types of finches varied from island to island, birds with similar diets had similar beaks. Darwin started to wonder if the birds "acquired" their bill shape in order to obtain food more efficiently.



Adaptations An adaptation is a trait based on the genotype of an organism. Each finch that Darwin observed had a beak that fit its preferred food source. Birds with big beaks preferred to eat hard seeds, those with pointed beaks preferred burrowing insects, and those with grabbing beaks tended to eat flying insects. The shape of each bird's beak is an example of an adaptation. An adaptation is a physical trait that gives an organism an advantage in surviving and reproducing in its environment. An adaptation should not be confused with the idea of adapting. If a behavior is learned, then it is a case of an individual adapting. An individual may adapt to its surroundings when it changes its behavior to fit in, or when it becomes used to a new environment. An adaptation is a genetic trait that is not learned, and does not change when the organism is placed in a new environment. Comparing Ecosystems Abiotic conditions vary in different ecosystems. An adaptation is a physical trait that gives an organism an advantage in a particular environment. Different ecosystems have different abiotic conditions. So in different ecosystems, organisms have different adaptations. An adaptation in one ecosystem would not always be an adaptation in a different ecosystem. For example, in the Arctic, it is an advantage for a polar bear to be white. This would not be an advantage in a tropical rain forest; the bear would be easily spotted among the green leaves and trees. Comparing Adaptations Organisms have traits that allow them to survive. Different environments have different conditions. Each organism must have adaptations to fit into its ecosystem or it will not survive. Now that you have seen some of the abiotic conditions present in some ecosystems, explore how adaptation works in different ecosystems. Specializations Different organisms have adaptations to accomplish similar processes. In the desert, all organisms must live with high temperatures and a scarcity of water. But not every organism has the same adaptation for these conditions. The owl, the cactus, and the rabbit all survive in extreme heat. The owl does this by hunting mainly at night when temperatures are lower. The cactus has very small leaves, or spines, to minimize water loss. It also retains water in its trunk. The rabbit has large ears. When the rabbit is in the shade, cooler air can blow over the blood vessels in the ears, which carries away extra heat. Purpose of Adaptations Adaptations allow an organism to reproduce successfully. An adaptation is a trait that increases the chance of an organism living to pass on its own genes. All organisms reproduce and pass on genes to offspring, but the methods to accomplish this vary widely from one species to the next. The method used by each species is an adaptation; it ensures the survival of that species. Some organisms have only one offspring at a time, while others have many offspring at a time. The drive to reproduce is a basic function of living things. It is how genes are passed through generations and the species continues. For reproduction to be successful, at least some of the offspring must survive long enough to reproduce themselves. There are many different adaptations for reproduction. Passing on Genes The strategy organisms use to reproduce must fit their ecosystem. The reproductive strategy that an organism employs ensures that the DNA of the parent will be passed down to members of the next generation. The reproductive strategy must fit with the organism's environment. Some organisms live in harsh environments, like the Arctic or the desert. These organisms have some interesting reproductive strategies to make sure that their genes are passed on.



Genetic Diversity

A species has a better chance of surviving if it is genetically diverse. Every environment creates competition for survival. A population with more alleles has more possible combinations of traits. This variety gives the species as a whole a better chance of continuing to exist. Organisms with more genetic variety will help to ensure that for every ecosystem, there will be organisms in the species that are adapted to live there. In a genetically diverse population, there will be many traits present. A species is more likely to survive if it is genetically diverse, because it has a variety of different possible adaptations.

Change Over Time

Darwin studied how populations changed over time. Darwin used his observations of the traits and adaptations of organisms in the Galápagos to write a ground-breaking study on how populations of organisms change over time. His observations changed the way that people looked at species, and the entire history of life on the planet. Based on his observation of species, he began to explore how populations of organisms could change over time. One of the organisms he studied was finches. Each species of the finches had adaptations in the size and shape of their beaks that allowed them to eat different types of food.

STUDY GUIDE



3.3.2 Quiz: (20 POINTS) Record your answers on the first page. 1. What question did Charles Darwin attempt to answer?

A. Why do organisms in different places have different traits?

B. Are some animals better at surviving than others?

C. Where is genetic material stored in the cell?

D. Can traits be passed between generations?



2. What is a reproductive strategy?

A. The method an organism uses to produce offspring

B. The adaptations that an offspring passes on

C. The number of alleles an organism passes on

D. The DNA that is passed onto an offspring

3. Which is true about adaptations?

A. They are genetically acquired traits.

B. They are acquired during an organism's lifetime.

C. They are learned from other organisms.

D. They are lost during an animal's life.

4. Why are certain traits adaptations in one environment, but not in another?

A. Some environments cause more mutations than others.

B. All environments have the same amount of competition.

C. Different environments have different abiotic conditions.

D. Organisms can learn new adaptations.



5. How are finches in the Galápagos Islands a good example of adaptation?

A. There is only one species of finch on those islands.

B. The finches do not have to compete for food.

C. They have adapted to be able to get different types of food.

D. It is very easy to train a finch to do tricks.

6. Which is an adaptation?

A. A horse breaks its leg while running.

B. A dog learns to roll over.

C. A camel has humps that store fat.

D. A cat learns to eat from a bowl.

7. In what way do adaptations help the survival of a species?

A. They reduce the number of alleles.

B. They increase the genetic diversity of the species.

C. They prevent reproduction from happening.

D. They ensure that many alleles are passed on.

8. Why are small leaves an adaptation in a desert environment?

A. They minimize water loss.

B. They trap less water.

C. They fall out in the winter.

D. They absorb more light.



9. Which would be an adaptation in a rainforest, but not in a desert?

A. Skin that blends in with green plants

B. Very small leaves to trap water

C. Better eyes for hunting prey

D. Ability to store water for a long time

10. What is the best reason that bright-colored feathers could be an adaptation for a bird living in a temperate forest?

A. It could make it harder for the bird to reproduce.

B. It could make it harder for the bird to hide.

C. It could make the bird a worse hunter.

D. It could make the bird attract mates.

3.3.3 Study: Natural Selection

Populations change over time.

Scientists Hardy and Weinberg showed that so long as certain factors do not exist, the genetics of a population do not

change over time. But we know that populations do change. Some species go extinct, and sometimes new species arise.

The adaptations of one environment gradually give way to new adaptations. How do these changes occur?

Studying the finches and other organisms in the Galápagos allowed Darwin to form ideas about how this change could

occur. His studies and the work of many scientists are the basis for the theory that explains how organisms change in

response to their environment. This is the theory of evolution by natural selection. One of the best-documented

examples of natural selection occurred in the populations of the peppered moth in England.



Changing Environments

Survival and reproductive success depends on an organism's adaptations.

The Industrial Revolution began at the end of the 18th century. New factories began producing new products, and along

with these new products came soot and other environmental pollution. Tons of soot was deposited in the countryside

around industrial areas. The soot discolored and darkened the surfaces of trees and rocks. It also killed the lichen that

covered the trees.

Adaptations and Survival

Organisms have adaptations that increase their chances of survival.

If you predicted that the dark moths would be more likely to survive, you would be right. The light color, which was an

adaptation when the trees were covered with lichen, became a problem when the trees became darker. Dark moths

now survived long enough to pass on their genes, which contained the mutant allele. More moths were born with the

allele for a darker color. The allele frequency of the moth population changed.

Differential Survival

Adaptations in one environment may not increase survival in another.

After several generations, there were fewer dark-colored moths than light-colored moths. When the trees were light in

color, it was harder to see the light-colored moths. The darker moths were more easily seen and eaten. Over several

generations, the light-colored moths were more likely to pass on their genes, so more light-colored moths were born.

What would happen to the distribution of moth alleles during the Industrial Revolution when the trees became dark? Change over Time

The moth population changed over time because of selective traits.

The activity you just completed reflects an actual environmental situation. Environmental pollution near industrial

centers continues to this day. As a result, in at least 70 different species of moths, the dark phenotype is more common

than the light phenotype. Many studies similar to the activity you completed on the previous page have been done. Here

is a sample of data that may be obtained from this type of study. Your results may not have come out exactly like this. Limited Resources

Natural selection is driven by predation and competition for resources.

Predation is only one factor that causes populations to change over time. Limited resources can also drive natural

selection. The idea that a limited food supply could affect population was first proposed by Thomas Malthus.



Thomas Malthus was an English economist who noticed that human populations were able to grow very rapidly —

doubling in size every 25 years.

The population size stops increasing when population exceeds food supply.

Malthus theorized that the food supply or other resources would eventually limit the population size.

He hypothesized that eventually a point would be reached when there would no longer be enough food for every

person. The idea that population size is limited by the food supply had a major influence on Darwin.

This idea would eventually be crucial to the development of Darwin's ideas on evolution. The Struggle for Survival

Over time, the more beneficial traits tend to survive.

Both abiotic resources — sunlight and the number of nesting sites, for example — and biotic resources like food supply

are limited in an environment. This causes populations to reach carrying capacity and stop growing. Once carrying

capacity is reached, organisms must compete for access to resources. Only those organisms with the highest fitness

would be "selected for"; those that are less fit would be "selected against," and may not survive.

This idea was the basis of a series of studies performed in the Galápagos Islands by a team of scientists.



The Theory of Evolution

Darwin proposed the theory of evolution.

Charles Darwin's The Origin of Species, published in 1859, describes his theory of evolution. In 1859, Charles Darwin published a book called The Origin of Species that described the theory of evolution. Darwin proposed that all organisms arose from a common ancestor and through natural selection evolved into the diversity, or variation, of life forms we can see today. Ever since Darwin first proposed the theory of evolution, scientists have collected data that support the theory. Variation and Natural Selection

Natural selection can only occur when genetic variation exists in a population. Charles Darwin recognized that certain individuals are better able to survive and reproduce than others. Natural selection favors these individuals and ensures that their traits continue from one generation to the next. As environments change due to factors like introduced species or climate change, the traits that were once adaptations may no longer help an organism survive. If every member of the population has this trait, then the species may all die off and go extinct. Populations that are variable are more likely to have individuals that possess the necessary genes to meet environmental changes. Conditions for Natural Selection

Natural selection occurs when resources are limited and population size is not. In addition to genetic variation in a population, for natural selection to occur, several other factors must be present. What might some of these factors be? Antibiotic Resistance

Genetic mutations in bacteria can make them resistant to antibiotics. The process of evolution by natural selection can be seen in the study of microorganisms like bacteria. With the advent of antibiotics such as penicillin, a powerful selective pressure was applied to bacteria. Those bacteria that survived penicillin treatment passed on their survival genes. Another cause of the problem is that different strains of bacteria are able to pass their resistance genes to each other, which increases the rate of spread of resistance. Antibiotic resistance is now a serious problem. The Importance of Evolution

The theory of evolution states that all life evolved from a common ancestor. Darwin suggested that all organisms evolved from a common ancestor. He proposed that the large number and variety of species on Earth was the result of lots of small changes adding up over time. According to this theory, organisms started from very simple life forms and eventually changed and adapted to all different types of environments. Darwin's ideas were a combination of the scientific ideas of his time with observations he made while traveling around the world. He slowly thought through the concepts of natural selection and survival of the fittest, then published his famous book.

STUDY GUIDE



3.3.4 Quiz: (20 POINTS) 1. What is the fitness of an organism?

A. The total population of a species

B. The ability to survive and reproduce

C. The environment the organism lives in

D. The number of resources an organism uses

2. What is the name for the process that causes a species to evolve?

A. Natural variation

B. Natural selection

C. Differentiation

D. Limitation

3. Which best summarizes the concept of natural selection?

A. Organisms best adapted to their environments survive.

B. The fittest organisms have the fewest offspring.

C. The oldest organism is the fittest for survival.

D. An organism will always mutate to survive.



4. How does natural selection lead to evolution?

A. Organisms with adaptations cannot pass them on.

B. Every generation is a new species.

C. A species can gradually change into a new species.

D. An organism always has the same traits as its parent.

5. Which best summarizes the peppered moths in England after the Industrial Revolution?

A. Moths learned to adapt to their environment.

B. A new mutation allowed moths to survive.

C. The light moths had an advantage.

D. The phenotype frequency changed.

6. How do peppered moths after the Industrial Revolution show the process of natural selection?

A. The white moths were more fit for survival, so their phenotype frequency increased.

B. The black moths were more fit for survival, so their phenotype frequency increased.

C. The black moths were more fit for survival, so their phenotype frequency decreased.

D. The white moths were more fit for survival, so their phenotype frequency decreased.



7. What must be true for natural selection to happen?

A. Resources must be limited in the ecosystem.

B. The population must be below carrying capacity.

C. There can be no competition for resources

D. There must be no predators in the ecosystem.

8. What did Malthus think would limit the population size?

A. Disease

B. Reproductive strategy

C. Food supply

D. Predators

9. An experiment is performed with peppered moths. The table below shows the populations before and after the trees turned black.

A. The light-colored moths mutated.

B. The dark-colored moths mutated.

C. The dark-colored moths were more fit.

D. The light-colored moths developed an adaptation.



10. A small number of finches are removed randomly from the wild and placed in a protected bird area. They are given as much food as they need and have plenty of space. Why would natural selection not occur in this population?

A. There is no reason for genetic mutation to occur.

B. The population has not reached carrying capacity.

C. The birds compete for limited resources.

D. There is no genetic variation in the finches.

Lesson 3.4 Study: Doing Science: Ecosystems and Natural Selection How might the complexity and timescale of natural events be handled in an experiment? In this lesson, you will find out how a common item can model a living thing, how random chance can represent a real-life situation, and how a simulation can help predict the outcome of an actual event. In an experiment titled "Natural Selection," you will use a model to test how environmental changes might affect genetic variation in a population of bears over several generations.

Objectives:

• Model a living thing by using a common item.

• Represent the complexity of the natural world by using random chance.

• Predict the outcome of an event by using a simulation.

• Communicate lab results with your peers in an online discussion.



Natural Selection

An impossible experiment is made possible with a simulation.

A robot is a simulation of a human being. Observation of the natural world is complicated by the complexity of living things and the duration of real events. To overcome these obstacles, a scientist uses a simulation. A simulation is an artificial representation of the natural world that can be used to do a controlled experiment. Think of a simulation as a model that shows how something moves or changes over time as it interacts with its environment.

In this study, you will learn how to

• create a model of a living thing or a real-life situation; • represent complexity in the natural world using random chance; • calculate the frequency of an observation; • observe a large population using a small sample; • predict the outcome of an actual event using a simulation.

Simulation as Experiment

A simulation represents the natural world in a simple form. A simulation allows a scientist to do an experiment that might otherwise be too complex or occur over too long a time span. In other words, a simulation makes it possible to do an otherwise impossible experiment. For example, an ecosystem involves countless interactions between organisms and the environment. Natural selection is a very slow process. How might a scientist observe an ecosystem without getting confused? How might she do an experiment on natural selection during her own lifetime? A simulation can be faster or slower than the event it represents, so that an experiment can be completed in a reasonable amount of time. Imitating Life

A living thing can be imitated using a common item. In a simulation, a common item is used to represent all or part of a living thing. For example, a piece of string might be used to represent a chromosome. In a simulation of cell division, string could be used to model the movement of each chromosome. A simulation allows a scientist to observe without a microscope and to move things around in a way that would be impossible with a living cell. Unlimited Repetitions

A simulation can be repeated an unlimited number of times. A simulation can be repeated again and again, so that a particular observation can be identified as either rare or typical. For example, a scientist might be interested in what happens to a human body during a car crash. To simulate a car crash, a scientist uses a crash-test dummy to represent an actual human body. The crash-test dummy can be put through an unlimited number of crashes without requiring medical treatment or even a lunch break. This sort of experiment would be impossible and unethical with an actual human being.



Duration of Real Events

A simulation artificially slows down or speeds up a real event. A simulation is like a time-lapse film that can be slowed down or sped up. An enzymatic reaction inside a living cell occurs so fast (sometimes within a millisecond) that it cannot be observed under normal circumstances. The process of evolution occurs so gradually (sometimes over hundreds of thousands of years) that it cannot be observed within a scientist's lifetime. A simulation allows a scientist to manage the duration of a real event so that it can be observed. For example, the speed of an enzymatic reaction can be simulated so that it occurs over a 10-minute period. Similarly, the process of evolution can be simulated so that it occurs within a single day.

Computer Simulations

A computer is a helpful tool for creating a simulation.

A video game might be a simulation of human activity. An event in the natural world can be simulated by reducing it to a series of steps. These can be written out as a set of instructions and then programmed into a computer. A computer helps a scientist by automatically repeating a series of steps an unlimited number of times and by reliably recording a large number of observations. Although the natural world is usually more complex than a simulation, the use of a computer allows more variables to be included, so that a simulation will more closely resemble a living thing or an actual event. A video game is a popular example of a computer-based simulation. In some games, a player controls when a character (or avatar) eats breakfast, goes to work, or watches television.

Parameters of a Simulation

The conditions of a simulation are set by selecting parameters. An antelope To create a simulation, a scientist establishes rules by which an artificial representation of the natural world operates. This is done through the selection of one or more parameters. A parameter is a measurable factor that affects a simulation. What happens in a simulation is guided by the value of each parameter. You could think of a parameter as the instructions for a simulation. For example, imagine a scientist uses a computer to simulate a herd of antelope drinking from a watering hole. Because the hole is the herd's only source of water, the scientist is interested in how fast the water will be depleted. One parameter in the simulation is the volume of water consumed by each individual antelope. Other parameters include the number of antelope in the herd, the amount of daily rainfall, and the rate of water loss due to evaporation.



Once the computer has the values for those parameters, the computer could be used to simulate the antelope drinking water. Probability and Random Chance

Random chance represents the complexity of the natural world. In real life, each antelope does not drink the same amount of water. Similarly, the amount of rainfall and the rate of evaporation are different on different days. A scientist incorporates this sort of complexity into a simulation by including random chance. Random chance is the probability that an event will occur naturally rather than by someone doing something on purpose. A familiar example of random chance is the outcome of a coin flip. When you flip a coin into the air and allow it to land without touching it, you are using random chance. The coin is predicted to land heads up 50 percent of the time. This is calculated as follows: (1 Head ÷ 2 Sides) x 100% = 50%.

Frequency of an Observation

The frequency of an event is also stated as a percentage. Frequency is a measure of the relative number of times something occurs in a certain situation or within a set period of time. To calculate the frequency of something, divide the number of times it occurs by the total number of possible occurrences. For example, suppose a scientist records 6 days of rainfall during a 30-day month. The frequency of daily rainfall is calculated as follows: (6 days of rainfall ÷ 30 days total) x 100% = 20%. Rainfall was observed 20 percent of the time during a one-month experiment. Sample of a Population

A large population is studied using a small sample. This small group of animals is a sample of the entire population. How might a scientist determine the average volume of water consumed by an antelope? Measuring the amount of water consumed by every antelope might be impossible. Instead, the average water consumed by a sample of 20 antelope can be calculated and used as the average for an entire population. The members of a sample should be chosen at random from the population. The size of the sample should be large enough to reflect the population's genetic variation.



Making Predictions A simulation can be used to predict the outcome of a real event. What might happen to a human body in an airplane crash? Once each parameter has been set and random chance has been incorporated, a simulation is used to predict the outcome of an actual event. For example, a simulation can be used to determine how quickly a watering hole is depleted of water during a hot, dry summer. Parameters such as the number of antelope or the probability of daily rainfall can be adjusted to resemble an actual watering hole. In a different simulation, a crash-test dummy can be used to test the effectiveness of a seat belt in a airplane crash. Parameters such as the weight of each crash-test dummy or the speed of the airplane can be adjusted to resemble an actual accident. Natural Selection

Success in the natural world is determined by survival and reproduction. The survival and reproductive success of a living thing can be influenced by an inherited trait. How does natural selection affect the frequency of a trait in a population over the course of several generations?

STUDY GUIDE



3.4.2 Quiz: (20 POINTS) 1. Which of the following is a good reason to use a simulation in an experiment?

A. To avoid measuring volume with a graduated cylinder

B. To ensure that no two observations are exactly the same

C. To predict the outcome of an event in the real world

D. To make an exact replication that is as complex as the real thing

2. A parachute helps a person jump from an airplane and reach the ground without injury. Which of the

following common items would best imitate the fragility of the human body in a simulation of a parachute jump?

A. A raw egg

B. A piece of gum

C. A rubber stopper

D. A golf ball

3. Suppose an actual bird is observed to lay from one to six eggs each week. Which of the following would be the best method for randomly determining how many eggs an imaginary bird lays in a simulation?

A. Rolling a six-sided number cube and using the number on the top side

B. Drawing from a deck of cards printed with either an uppercase or lowercase Q

C. Throwing a dart at a dartboard hanging on a wall at a distance of 10 feet

D. Blindly selecting from a bag filled with blue, green, red, and yellow beads



4. Random chance is an important part of a simulation because it is a way to imitate the complexity of the natural world. By incorporating random chance, a scientist ensures that a series of steps are followed:

A. in a slightly different way each time.

B. exactly the same way every time.

C. to the end without any step being skipped.

D. backwards or in a reverse manner.

5. In a herd of 80 dairy cows, 16 have black-and-white coats, and 64 have solid black coats. What is the

frequency of cows with black-and-white coats?

A. 16%

B. 20%

C. 64%

D. 80%

6. Over a 200-year period, a volcano erupted once. According to this information, what is the yearly frequency of volcanic eruption?

A. 99%

B. 20%

C. 0.5%

D. 1%



7. To create a simulation of 100,000 ants moving around inside a colony, a scientist needs to determine the

average traveling speed for an actual ant. Which of the following is the best course of action for establishing this parameter?

A. Measure the traveling speed of a single ant, and assume all ants are the same.

B. Determine the average traveling speed for 20 randomly selected ants.

C. Choose a random value to represent the average traveling speed of an ant.

D. Divide the total distance traveled by 100,000 ants in a day by 24 hours.

8. A sample of a population should be large enough to:

A. include more than half of the entire population.

B. span the full spectrum of a population's genetic variation.

C. generate a very large amount of data.

D. justify the cost of the items needed for the simulation.

9. A scientist wonders what would happen if 10 million liters of crude oil were dumped into Lake Michigan.

Which of the following is the most ethical reason for running a simulation rather than dumping actual oil into Lake Michigan?

A. A computer should always be used in an experiment.

B. An experiment should cause no harm to the natural world.

C. It is too expensive to buy that much crude oil for an experiment.

D. A scientist might live too far from Lake Michigan to observe it easily.



10.Which of the following describes a possible benefit of a failed simulation?

A. The presence of an uncontrolled variable might be revealed.

B. No simulation is reliable, and so it should not have been trusted anyway.

C. An artificial representation is easier to dispose of than the real thing.

D. A failed simulation does not provide any benefit whatsoever.

Next Week’s Lesson: Unit 3 TEST

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ecosystems and natural selection

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