solved Below are two sets of questions that are intended to

Below are two sets of questions that are intended to reinforce key concepts that have or will be covered in the next few classes. The first set is focused on evolution and how to use phylogenetic trees as tools for understanding the history of life on earth and the second is focused on the history of earliest life on Earth. Each questions is worth 5 points.
Evolution, Phylogeny and Reading Family Trees
Read the following pages on UC Berkeley’s Understanding Evolution site:
https://evolution.berkeley.edu/evolibrary/article/evo_01 (Links to an external site.)

Read from the introduction through “Mechanisms of Change”
Read “Macroevolution” and “The Big Issues” through “Diversity in Clades”

http://evolution.berkeley.edu/evolibrary/article/0_0_0/evotrees_intro (Links to an external site.)

Read through “Tree Reading Tips”

Complete the reading and viewing and then answer the following questions:
As discussed in class, through descent with modification, the common ancestor of all life on Earth gave rise to the diversity of life we see today. We did not discuss in any detail how “lineages” of life split to give rise to this diversity. This set of questions should help you understand lineage splitting. Note that we use the websites above uses a term “clade”. In the class on phylogentics, this was called a monophyletic group. So monophyletic group = clade.

Briefly describe the concept of Natural Selection. Include the four elements discussed in class. (Go to the class slides)
Briefly describe macroevolution. (1-2 sentences)
What is a transition fossil (transitional form)?
Look up transition fossils online and describe one example (don’t use whales). (1-2 sentences).

Use this figure to answer the question below:
Blue Green Red

5. What color(s) on the diagram above represent monophyletic groups (clades)? What color(s) do(es) not represent a monophyletic group? What two colors can be combined to make a monophyletic group?
6. Using the OneZoom Tree of Life (Links to an external site.) exploration tool found here (Links to an external site.), navigate your way to humans. It may take a bit to get used to the tool. List five nested “clades” or monophyletic groups that include humans, starting anywhere you like in the tree. There is no single answer to this question. Remember that a clade is a branch of the tree and all of the smaller branches that are included on that branch.
7. Using the diagram here (Links to an external site.), which are more closely related? Explain your logic in 1-2 sentences maximum.
a. Crocodiles and amphibians
b. Crocodiles and primates
8. List the animals on this diagram that have 4 limbs (tetrapods).
9. What characteristic distinguishes the clade (monophyletic group) that includes primates and birds from the one that includes amphibians? Look up that characteristic using internet resources and describe it in 1-2 sentences.
Read this short article on cetacean (including whale) evolution
https://evolution.berkeley.edu/evolibrary/article/0_0_0/evograms_03 (Links to an external site.)
and watch this short film on evolution
https://www.youtube.com/watch?v=lIEoO5KdPvg (Links to an external site.)

10. List five pieces of evidence for whale evolution from land mammals (be specific, don’t just list the general lines of evidence like “comparative anatomy”. Give a specific example in that or the other categories.
11. Describe the bones in the front flipper of a whale. Are they more similar to a bat wing or a ray-finned fish fin (look this up if you need too).
12. From the film on evolution, what characteristics and behaviors do hippos and whales share? Name five.
History of life on earth
Use the following interactive to answer the questions
https://media.hhmi.org/biointeractive/click/oxygen/ (Links to an external site.)
Note: Here is a definition that will be important as we move on through the course material.
Adaptation: An adaptation is a feature that is common in a population because it provides some improved function.
Click on Stage 1 and read the “Environment” and “Life” tabs in the upper right
13. What major categories of life existed during this time?
14. List two pieces of evidence for life on Earth during this time. One sentence each (really).
Click on Stage 2 and read the “Environment” and “Life” tabs in the upper right
15. What major categories of life existed during this time?
16. What adaptation did eukaryotes have that allowed them to evolve and diversify during Stage 2 in this interactive diagram? (Answer is in the Life tab)
Click on Stage 3 and read the “Environment” and “Life” tabs in the upper right
17. What is the impact of relatively low and steady O2 levels on life during this “boring billion” years of earth history?
18. Click on Howie in the lower right. Briefly describe how chloroplasts evolved.
19. How did life evolve in response to the increase in O2 during Stage 4? (click on Howie and watch the video clip)
20. What caused O2 to increase in Stage 5? How did life on earth respond to this increase?