Investigating Evolutionary Questions Using Online Molecular Databases, Part I

From ENSI, Indiana University

 

Name: __________________________________________________  Period: _____________________________

 

Building a Phylogenetic Tree

Are humans more closely related to a monkey or a gorilla? You are about to see how scientists measure evolutionary relationships to organize phylogenetic trees. A phylogenetic tree show the evolutionary relationship among organisms. Closely related organisms are located near one another on the tree.

 

Phylo

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Look at the list of organisms on the following page in Table 1.  Write a hypothesis ranking the organisms by how closely related they are to humans. List them from the most related to the least related and include all eight organisms. Write your hypothesis in the spaces below.

 

 

Humans ________________ _________________ __________________ __________________

 

______________________ ___________________ __________________

 

 

 

 

 

 

 

 

 

 

Data and Questions

 

Table 1: List of species

 

Species

Species number (Accession Number)

Scientific name  (Genus and Species)

Human

 

 

Horse

 

 

Sheep

 

 

Atlantic Salmon

 

 

Western Painted Turtle

 

 

Nile Crocodile

 

 

Gorilla

 

 

Port Jackson Shark

 

 

 

 

 

Table 2: Distance matrix

 

 

 

Write the percent similarity as shown in the directions.

 

 

Human

Horse

Sheep

Atlantic Salmon

Western Painted Turtle

Nile Crocodile

 

Lowland Gorilla

Port Jackson Shark

Human

100%

 

 

 

 

 

 

 

Horse

 

100%

93.1%

83.0%

87.7%

81.6%

93.8%

69.9%

Sheep

 

 

100%

78.5%

88.8%

82.3%

93.1%

69.3%

Atlantic Salmon

 

 

 

100%

76.9%

71.6%

79.1%

68.0%

Western Painted Turtle

 

 

 

 

100%

86.4%

88.4%

69.2%

Nile Crocodile

 

 

 

 

 

100%

83.3%

65.0%

Gorilla

 

 

 

 

 

 

100%

69.9%

Port Jackson Shark

 

 

 

 

 

 

 

100%

 

 

 

 

 

 

 

 

Analysis

 

  1. Using the information from the data table above, place each of the eight organisms in the correct location on the phylogenetic tree.  The top of the tree represents organisms that evolved more recently.

 

  

Questions:

  1. What is a cladogram?

 

 

 

  1. What is a clade? How many clades are in the above cladogram?

 

 

 

  1. What derived character are we really comparing when we compare a protein between two organisms? (HINT: What molecule contains the information on how to make proteins? Write a full sentence.)

 

 

 

  1. What derived character describes the first (oldest) clade?

 

 

  1. Which two organisms branched off from the last (most recent) node?

 

 

6.      Which two species in the above table have the most similar beta-hemoglobin chains?

 

 

7.      Which two species in the above table have the fewest similarities in the beta-hemoglobin chain?

 

 

  1. Which are more closely related; a crocodile and a turtle, or a crocodile and a shark? Explain how you can tell by looking at the percentages of beta-hemoglobin chains and the phylogenic tree or cladogram you filled in.  (Give their relative locations to one another on the tree and give the percentage of similarity.)

 

 

 

 

  1. Use the www.uniprot.org website to determine the similarity in Beta Hemoglobin to human. Type Atlantic Bottle-nosed Dolphin hbb in the query box and then click the align button again. Copy the sequence up at the top of the page like you did before into the second website). Comparing humans to dolphins, what is the percentage of similarity in their hemoglobin?  Write the percentage below and then use it to draw a line for the dolphins on the phylogenic tree or cladogram. Label it DOLPHIN.

 

 

  1. Explain using percentages why you put the line for Atlantic Bottle-nosed Dolphin where you did.

 

 

 

 

  1. Explain in terms of derived characters why the Atlantic Bottle-nosed Dolphin fits into the clade that it does? (HINT: Think carefully!! Just because organisms share a similar environment doesnt mean they are closely related.)