BIOEE_274_ToL_assignment_Answer_Key - BIOEE 274 The...

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1 BIOEE 274 The Vertebrates: Structure, Function, and Evolution Name: __ Answer key___ ________ TA: ______________________ Lab 1: Phylogenetics and Tree of Life Exercises Part 1. Tree of Life Exercises The Tree of Life Web Project ( ToL ) is a collaborative effort of biologists from around the world. Encompassing more than 3000 World Wide Web pages, the project provides information about the diversity of organisms on Earth, their evolutionary history (phylogeny), and characteristics. Each page contains information about a particular group of organisms (e.g., echinoderms, tyrannosaurs, phlox flowers, cephalopods, club fungi). Tree of Life pages are linked one to another hierarchically, representing relationships among organisms in the evolutionary tree of life. Starting with the root of all life on Earth and moving out along diverging branches to individual species, the structure of the ToL project thus illustrates the genetic relationships among all living things. Before you start these exercises, navigate through a few lineages in the ToL to become acquainted with how the tree is organized. Remember, when you click on more derived clades, you are essentially moving along the branches of the tree from ancestral nodes to more recent taxa. 1) Begin at the ToL home page: In the upper left of the page, locate the Root of the Tree link. Click on this link and navigate through the basal clades of the tree to the Gnathostomata page. To do this you will follow the lineage that leads to vertebrates. Do you recall what key morphological feature is characteristic of the Gnathostomata? a) How many nodes are shown in the tree on the Gnathostomata page? 3 nodes (4 if you include the root) How many branches? 8 branches How many monophyletic groups? 4 monophyletic groups b) A group that includes only Sarcopterygii and Chondrichthyes would be considered to be (circle one): monophyletic paraphyletic polyphyletic 2) Navigate through the vertebrate tree to the Terrestrial Vertebrates page. a) On this page, find the list of shared derived characters that define Tetrapoda , and list five of those characters here. 1. A layer of dead, horny cells that reduces evaporative water loss. 2.
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This note was uploaded on 02/23/2009 for the course BIOEE 2740 taught by Professor Zamudio,k. during the Spring '07 term at Cornell University (Engineering School).

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BIOEE_274_ToL_assignment_Answer_Key - BIOEE 274 The...

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