LS7B Week 7 Pre Class Worksheet Fill out this worksheet as you complete your pre class assignments Bring your completed worksheet to class to use as a reference for in class activities Name After completing your pre class assignments you should be able to Define adaptive radiation Explain the role of mass extinctions to diversification after the extinction event Identify the role of fossil evidence and phylogenies to our understanding of evolutionary patterns Determine the age of a fossil based on 14C dating Recognize major events documenting the appearance of major groups in the evolution of life on Earth 1 Define adaptive radiation Write down a description or you can draw a tree of what you think an adaptive radiation would look like on a phylogenetic tree 2 Based on your understanding of fossil formation which of the following would you expect to be more likely to fossilize Be sure to include your reasoning with your answer A a common squirrel that lives near the edge of a lake B A rare squirrel that lives in a tropical rainforest 3 How many mass extinctions have we documented in the past and when did they occur What can be said about rates of diversification in different taxonomic groups after a mass extinction event 4 You have found a fossil that you think is approximately 18 000 years old What ratio of 14C 14N would you expect Can you use carbon 14 dating for any fossil you may find Why or why not 5 Describe how fossils can complement other types of data when building and interpreting phylogenies 6 Given the following character matrix TRY to construct a phylogenetic tree showing the relationship among these taxa For a little help Identify the character that is shared by the most taxa first then the character that is shared by the next greatest number of taxa This should help you determine the nodes synapomorphies and monophyletic groups in the phylogeny of these groups Don t worry if you don t feel like you can do it you will get more practice in class with your instructor 7 Draw a timeline showing the history of life on Earth for the past 600 my On your timeline show the appearance of the first animals first vertebrates first terrestrial plants and first terrestrial animals