SCIN 130 AMU Lab 2 Common Descent Introduction to Biology American Military University assistance is available on Domyclass
Step 1: Read and complete the Lesson for the week – both the Lecture and Lab portion found in the APUS online classroom! The information you acquire in this Lab will be included in your quiz for the week – so make sure you have it completed prior to taking the quiz!
Step 2: Complete all the activities in this lab instruction packet: SCIN 130 Lab 2: Common Descent. Work through the instruction packet step by step. Record your results in the worksheet as you progress through this instruction packet.
Step 3: You should save a copy of your completed lab with your name and lab # in the title. For example, if you are Felicetti and this is lab 2, you would title your document: FelicettiLab2.doc. You are then to add this as an attachment to the quiz for the week!
Please note the following:
For any sections that request that you “take notes”, the notes should be in your own words summarizing information learned. You should not copy and paste information from the Internet including media and resources accessed in this lab. Directly copying and pasting information is considered plagiarism in this course.
When taking screenshots save with file name that has your last name, the lab number and the screenshot number. For example, for the first screenshot in lab 2 if your last name was Felicetti the file name would be FelicettiLab2Shot1.jpeg. It is important to follow this image labeling structure. Images submitted without proper labeling will be graded as a zero.
This lab instruction packet will be submitted with the quiz for the week when completed. Again, save the file with your name and the lab number as a Word document. For example, if this was Lab 2 and your last name was Felicetti the file name would be FelicettiLab2.docx. It is important to follow this file labeling structure. Files submitted without proper labeling are subject to a score of zero.
SCIN 130 Lab 2: Common Descent
Be sure to read the general instructions from the Lessons portion of the class prior to completing this packet.
Remember, you are to upload this packet with your quiz for the week!
Key concepts from this lab to remember:
- Species descend from other species. Even distantly related species, like humans and sponges, can trace their shared ancestry back to a common ancestor.
- Evidence for common descent includes the fossil record and anatomical, genetic, and developmental homologies among organisms.
- The fossil record provides a history of life on Earth. It includes fossils with features that are intermediate, or transitional, between those of major groups of animals.
- When a series of transitional fossils are viewed together, they reveal the gradual sequence of change connecting one major group to another.
- An organism’s DNA codes for proteins that result in an organism’s visible traits.
- Scientists infer function and behavior from anatomical structures.
- Natural selection is the process by which heritable traits that confer a survival and/or reproductive advantage to individuals that possess them increase in frequency within a population over generations.
Specific Lab Instructions
Part 1: Explore Your Inner Animals
Notice the highlighted sections on the human:
When you click on each highlighted area, a list of animals with homologous structures appear on the right. For this portion of the lab, you must click on each animal to view the connection to humans.
When complete with one view, rotate the human, click on another anatomical structure in humans, explore the connection to other animals.
Repeat this click and rotate process until
you have viewed all of the highlighted structures and associated animal
Answer the following questions based on your explorations of the body:
1. How do we know that Kramer cannot see the same way most humans can?
2. Describe what the “clues” scientists found in our DNA suggest about how humans might have evolved enhanced color vision.
1. Describe the anatomical features of Ardi’s upper and lower pelvis and what they indicate about how Ardi may have moved.
2. Does Ardi’s foot structure support or refute the idea that Ardi was a creature in transition? Explain your answer.
1. What are three bones are found in the middle ears of all mammals, including humans?
2. Explain why mammalian ears are more sensitive to sound than those of reptiles.
1. Describe what features the modern human hand shares with the hand of the 50 million year-old primate, Notharctus.
2. How did Darwin explain common patterns like these among vertebrates?
1. How many million years ago did the “first roots” of our modern human brain arise?
2. Describe how our human brain is similar to the brains of other primates.
1. What is another word for coccyx?
2. What is one of the easiest ways to distinguish an ape from a monkey?
1. What is an advantage of chewing food over swallowing it whole?
2. Why are teeth so important to paleontologists?
Review the Introduction, and then Begin the Simulation
A Quick Guide will pop up first – make sure to read it so you know how to navigate the page!
Excavate each fossil in the rock layers. When all are excavated, click each to view more details. Then, click on the underlined column headings for more information on structures. Finally, answer the questions below.
- Tetrapods first appeared in the fossil record how many million years ago?
- Of the fossils presented, which was the first to be discovered by humans? In what year?
- What did Charles Darwin predict that tetrapods evolved from? What observations led him to that hypothesis?
- What is the purpose of gills in fish?
- Why did lungs develop in fish, leading to tetrapods?
- What do we mean in biology when we use the term homology?
- To what are fins homologous?
- Explain the importance of a sturdy ribcage in tetrapods.
- Why do many of the transitional fossils between fish and tetrapods have flat heads?
- Why is Tiktaalik such an important transitional fossil?
- What is the only surviving member of the lobe finned fish?
Part 1 Adapted from:
Click and Learn “Explore Your Inner Animals” (2016). HHMI Biointeractive Teaching Materials.
Part 2 Adapted from:
Click and Learn “Great Transitions Interactive” (2017). HHMI Biointeractive Teaching Materials.