2.13

Bats in the Bellfry

Background Information:

Although much is known about Charles Darwin, very little is known about his younger brother Robert. Recently, an audio and written diary was uncovered in which Robert details his shipwreck and subsequent isolation on an uncharted group of islands 500 miles off the coast of Australopithecus. For our purposes in this lab, we will only be listening to the parts of his diary which relate to his discovery of five new species of bats found no where else in the world. In his diary he drew pictures of the bats (unfortunately he was no Michaelangelo) All the bats were similar to a single species 0f bat found on the mainland. During his time on the island he observed and recorded the number and special characteristics of the different species of bats.

I. Purpose:

Based on the anatomical adaptations of the bats found on the islands, you will predict the ecologicaI niche of each bat, and how each adaptation may have developed. You will also predict how stress effects the bat populations and how an organism you select may go through the process of natural selection to evolve adaptations that will help it survive in a new environment.

Audio Diary

The island that I find myself on is uninhabited (at least as far as I can see) by any humans. It appears to belong to a small group of islands somewhere west of Australopithecus, from which I departed on a schooner several days ago. A hurricane-like storm blew up and here I am. I seem to be the only survivor...

Something is very unusual. I have been here two days now and have not seen or heard a bird...

There is one thing about this island that I must tell my brother Charles about, it is the appearance of a number of peculiar bats. They all appear similar to a species I have encountered on the mainland, but seem to have become modified into five different species. I have observed that the bats are different from each other in size. Each bat also has a different type and number of teeth. Their eyes and ears serve different purposes and the length of their snout varies from bat to bat. Each bat has unique claws and their limbs serve different purposes.

Although I have not observed any of the bats eating, there seems to be a number of different food sources available. For example, in the shallow pools of water in the intertidal zones are a number of small fish. The island also has an abundance of flying insects and several ground insects, including ants, termites and beetles. There are some underground inhabitants such as insect grubs and earthworms. Plant life with fruits, flowers, seeds and nuts are also in abundance.

That was the last entry in Robert’s diary. His work remains unfinished and that is probably why you never heard of him. Our task is to help him complete his work and try to bring him some recognition for the part he played in the theory of natural selection.

II. Problems:

A. Based on the food available on the island and the bat’s adaptations, what type of food would each species of bat consume?

B. What is the niche of each bat?

C. What could have caused these bats to appear on this island and nowhere else in the world?

III. Hypothesis:

Write your hypothesis for each problem on the answer sheet on the Day 1 answer sheet.

IV. Procedure – Day 1:

(Record all Day 1 information in the Data section of the lab report.)

The hypothesis for problems A, B, and C should be completed before going on.

1. Your second task is to give each species of bat a Genus and species name. You should investigate how scientists name organisms. It would be helpful to research the scientific names of bats. Record the names and rationale for the names in the space provided on Day 1 answer sheet in Table 1.

2. You have been asked to write an online newsletter for a major science magazine called Scientific American. They want a brief newsletter that addresses the idea that the bats from this island may have evolved from a mainland ancestor. The editor has requested that your newsletter contain the following concepts and terms which will be highlighted on this month’s website: “Variations”, “Survival of the Fittest”, “Geographic Isolation”, and “Speciation”. Your article should follow the same format of their existing newsletters. To preview existing newsletters and the Scientific American Online site go to: http://www.sciam.com/. Your newsletter may include graphs, diagrams, and any other supporting evidence you need.

Procedure - Day 2:

(Record all Day 2 information in the Data Analysis section of the lab report.)

1. What luck! Some missing pages of Darwin’s diary have just been discovered. It appears that Darwin did record the kinds of food the different bats ate. Obtain a copy of this “lost” page from your teacher and compare your hypothesis with the information Darwin recorded.

Ø  Does this information support or reject your hypothesis?

2. Based on your study so far, create an evolutionary tree that you believe represents the ancestral descent of the bats on this island. Label this tree “Bat Evolutionary Tree 1844”

3. In 1950 an oil tanker broke apart on the reef that surrounds this group of islands. It spilled hundreds of thousands of barrels of crude oil into the sea around the island.

Ø  Predict what effect this catastrophe might have had on the bat populations on the island. Support each of your predictions with some rationale.

4. In 1990 a single pair of breeding robins was inadvertently left on the island.

Ø  What would you predict the consequences to the bat populations to be? Explain why you think so.

5. Assuming both of the above took place, create a new evolutionary tree that will describe the bat populations 20 years in the future. Label this tree “Bat Evolutionary Tree 2014”.

Procedure – Day 3:

(Record all Day 3 information in the Data Analysis section of the lab report.)

I. Again we are in luck! Wendy Bailey, Jerry Slightom and Morris Goodman of Wayne State University have been sent some blood from our bats and have agreed to run some DNA tests on the hemoglobin molecules. A copy of the analysis is in the Day 3 packet. Analyze this new information.

Ø  Does this new information support or reject your 1844 Bat Evolutionary Tree? Draw a new tree based on the information in the DNA analysis. How did this new information modify your tree?

2. A group of biologists was recently sent to the island to record the number of each species of bat. There results are found in the Day 3 packet.

Ø  Determine whether the bat census in 1994 supports or rejects your 2014 evolutionary tree.

Bats in the Bellfry

Student Answer Sheet

Name: ______Date: ______

DAY 1

Hypothesis:

1.) Table 1. Predicted Food Consumption

Bat / Food / Supporting Evidence
A
B
C
D
E

2.) Table 2. Niche Predictions

Bat / Niche / Supporting Evidence
A
B
C
D
E

3.) The appearance of these bats on this island and nowhere else in the world can be explained by…

______

Data:

1.) Table 3. Scientific Names

Bat / Scientific Name / Rationale
A
B
C
D
E

2.) The newsletter for Scientific American Online will be typed on a separate sheet of paper.

DAY 2

Data Analysis:

1.) Table 4. Hypothesis Supported or Rejected?

Bat / Supported/Rejected / Actual Food Eaten by the Bats
A
B
C
D
E

2.) Diagram 1. Bat Evolutionary Tree 1844

3.) Effect of the 1950 Oil Spill

______

4.) Effect of Robins

______

5.) Diagram 2. Bat Evolutionary Tree 2014

DAY 3

Data Analysis:

1.) Diagram 3. DNA Analysis Tree

______

2.) Support or Reject 2014 Evolutionary Tree

______