Take 1-2 minutes to think about your definition of evolution. Share with your table your thoughts and collaborate to write a common definition of evolution on the white boards. Be prepared to share.

Simulation Question Why do giraffes have such long necks?

Giraffe Simulation You are going to be competing as giraffes for food. Looking around the room, predict who you think the winners of the simulation will be. Why did you pick those giraffes? How will future generations of giraffes compare to the current generation if the predicted giraffes survive? Why?

Expectations: Each half of the room will have opportunities to eat. Giraffes do not jump, climb, or use others for food. Your hooves must stay firmly rooted on the ground. If you do not eat, you do not survive to the next round.

Comparing Predictions to Results How did your predictions compare to the actual results of the simulation? Do you feel that this is an accurate representation of what happens in nature? Why or why not? Explain how this simulation relates to evolution.

Evolution Part 1

THEORIES THAT HELPED SHAPE EVOLUTION

Why do we study evolution? Evolution is required to be taught by the State of Michigan. You will be tested on evolution topics on the M-Step and NWEA. The more you know about both sides of a topic, the more successful you are at arguing your side. My job is to present the science of evolution to you, not to discuss personal beliefs.

I can define a theory and give examples. I can define a law and give examples. I can explain the theories that helped shape Darwin’s theory. I can explain the theory of evolution.

Note Expectations: Cell phones and electronics are not in use. You are taking the notes. You are helping the people at your table to answer the questions. You are prepared to answer the questions.

How old do you think the Earth is? What evidence do we have to support the age of the Earth? What processes helped to shape the Earth as it is today?

During the 18 th and 19 th centuries, scientists determined the Earth was billions of years old. The processes that shaped the Earth millions of years ago are still working today.

What is your definition of an adaptation? Give examples of a deer’s adaptations.

Lamarck was one of the first scientists to recognize that living things have changed over time. He also recognized that organisms adapt to their environments. Lamarck proposed that by the use or disuse of organs, organisms acquired or lost certain traits during their lifetime. These traits could then be passed on to their offspring.

What organ in our bodies has no known function? If Lamark’s theory is right, what does that mean about the fate of that organ?

Over time, this process led to changes in a species. He proposed that all organisms have a tendency toward perfection and complexity. Therefore, they continuously change to help them survive more successfully.

If you have surgery to remove your gall bladder, will your children be born with a gall bladder? Why or why not? Can all traits be passed onto your offspring? Why or why not? What traits can be passed on? Define the word acquired.

In his view, the ancestors of birds had an urge to fly, so they developed wings. Lamarck thought that acquired characteristics could be passed on to the next generation of offspring. An acquired characteristic is a trait that you gain during your lifetime, like getting a tattoo or having surgery.

How does Lamarack’s idea for giraffes long necks compare to our simulation?

According to his theory, if you had your appendix taken out, your children would not have one either. Even though his theory was wrong, Lamarck developed the first theory of evolution.

What scientist is given credit for the current theory of evolution? What do you know about that scientist? Review Question: What is science based on?

Darwin published his theory of evolution in 1859 after years of research on the Galapagos Islands. His book was called: On the Origin of Species

During his travels, Darwin’s observations lead him to make a hypothesis. He proposed that organisms change over time. As a result of this change, modern organisms are descended from ancient organisms.

Review: What is a hypothesis? Review: What is a theory? How is a hypothesis different than a theory?

Evolution is a theory that states organisms change over time. Remember, a theory is a well supported testable explanation of things that occur in the natural world. In other words, a theory is the best scientific explanation available.

A theory is accepted as true until someone is able to disprove it.

When will a theory be rejected? Has the theory of evolution been rejected? Why or why not?

Summary Of Darwin’s Theory Individual organisms in nature differ from one another. Some of this variation is inherited. What is variation? Organisms in nature produce more offspring than can survive and many do not reproduce. Why do organisms produce lots of offspring?

Summary Of Darwin’s Theory Since so many organisms are produced, they must compete for a limited number of resources. Why is competition important? What do organisms compete over? Each organism is unique, so they have certain advantages and disadvantages for survival. What does the word unique mean?

Summary Of Darwin’s Theory Individuals best suited for their environment survive and reproduce more successfully, and they pass on their characteristics to their offspring. Are all organisms created equal? Why or why not?

Summary Of Darwin’s Theory Species change over time, and new species arise while other species disappear. Have humans changed over time? If so, how? What is it called when a species disappears?

Species alive today have adapted with modifications from species that lived in the past. What does the word modifications mean? All organisms on Earth are unified into a single tree of life by common descent. What evidence do we have to link organisms into a tree of life?

Review Questions Who developed the first theory of evolution? What is an acquired characteristic? What types of characteristics can be passed onto offspring? Why was Lamarck’s theory of evolution incorrect? What is a theory? How does a theory compare to a hypothesis? What does the theory of evolution state?

NATURAL SELECTION

I can explain and give examples of natural variation. I can explain fitness. I can define and give examples of adaptations. I can explain the idea of survival of the fittest. I can define and explain the process of natural selection.

Note Expectations: Cell phones and electronics are not in use. You are taking the notes. You are helping the people at your table to answer the questions. You are prepared to answer the questions.

What is variation? Give examples of variation in this classroom.

Species are not perfect and unchanging. Instead, there is natural variation within a species.

Natural variation is defined as differences between individuals of the same species. Examples of natural variation include: Fruit production, milk production in cows, height.

Farmers and breeders often artificially select for the best traits for animals and plants to make them bigger and better. Darwin proposed that nature must also have a selection process.

Prediction: What is natural selection? Why do organisms compete with each other? What type of organism is most likely to survive, one that is better suited to the environment or less suited?

The struggle for existence states that organisms compete with each other for limited resources. An organism that is better suited to the environment should have a better chance for survival and reproduction.

What do you think fitness means in terms of an organism? Define adaptation. What role do you think an organism’s adaptations have in its fitness?

Fitness is the ability of an individual to survive and reproduce in a specific environment. Darwin proposed that fitness is related to an organism’s adaptations. An adaptation is any inherited characteristic or trait that increases an organism’s chance of survival.

Examples of adaptations include: camouflage, speed, toxins, and behaviors. Individuals with successful adaptations are more likely to survive and reproduce. Individuals that are less adapted are less likely to survive and reproduce.

Predict what the phrase survival of the fittest means.

Darwin named the process the survival of the fittest. Today, we refer to it as natural selection. Nature selects the best characteristics for a species and they change over time.

How does natural selection affect a species? Why? Will natural selection increase or decrease a species fitness? Do you think natural selection works on individuals or a species as a whole? Is natural selection a fast or slow process? Why?

Over time, natural selection results in changes in the traits of a population. These changes increase a species fitness over time. Natural selection can only be seen by studying several generations of the same species.

EVIDENCE FOR EVOLUTION

I can describe the principle of descent with modification. I can list and describe three sources of evidence for evolution. I can give examples of homologous structures. I can explain how embryonic development provides evidence for evolution.

Note Expectations: Cell phones and electronics are not in use. You are taking the notes. You are helping the people at your table to answer the questions. You are prepared to answer the questions.

How do species today compare to those on Earth 100 years ago? Are they identical or different? Why? What does the word modification mean?

Darwin proposed that over long periods of time, natural selection produces organisms that have different structures, niches or habitats. As a result, species today look different than their ancestors.

This principle is called descent with modification. This principle implies that all living organisms are related to each other. According to the principle of common descent, all living and extinct species come from common ancestors.

These principles produce a single tree of life that links all living things.

What types of things provide evidence for evolution?

Evidence for evolution can be found in: Fossil record, homologous structures, and similarities in development.

How did fossils form? What can we learn from studying fossils?

The fossil record was formed as different layers of rock were added at different times in history. Dating and studying fossils reveals how organisms change over time. In addition to fossils, living organisms can also provide evidence for evolution.

What are vertebrates? What do all vertebrates have in common?

Vertebrates are animals with backbones. If you look at the bones in the limbs of vertebrates, you find similarities, even though the limbs are arms, wings, legs, and even flippers.

The limbs differ in form and function, but they are made from the same basic bones. All the limbs in vertebrates develop from the same clump of cells in growing embryos. What does the prefix homo- mean?

Homologous structures are structures that develop from the same embryonic tissue. Homologous structures can be used to group organisms together and give evidence for evolution.

Some homologous structures may not be used any longer. Vestigial organs are traces of homologous structures with little or no function. An example of a vestigial organ in humans is the appendix.

In addition to homologous structures, organisms that are closely related to each other develop in similar ways. Embryonic development also provides evidence for evolution.

All vertebrates start with the same groups of embryonic cells that develop in the same order and in a similar pattern.

Review Questions What 3 things provide evidence for evolution? What can we learn from fossils? What are homologous structures? Give examples from vertebrates. What are vestigial organs? Give an example from humans. How does embryonic development provide evidence for evolution?