Description
Complete all the activities in the attached lab instruction packet: SCIN 130 Lab 4: Stickleback Evolution, Part 2. Work through the instruction packet step by step. Record your results in the worksheet as you progress through this instruction packet.
For any sections that request that you “take notes”, the notes should be in your own words summarizing information learned. You should not copy and paste information from the Internet including media and resources accessed in this lab. Directly copying and pasting information is considered plagiarism in this course.
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Explanation & Answer
Attached.
SCIN130 Lab 4: Stickleback Evolution, Part 2
SCIN 130 Lab 4: Stickleback
Evolution, Part 2
General Instructions
Be sure to read the general instructions from the Lessons portion of
the class prior to completing this packet.
Remember, you are to upload this packet with your quiz for the
week!
Background
In this experiment, you will analyze the pelvic structures of stickleback fish
collected from two lakes around Cook Inlet, Alaska, to determine whether
there are significant differences between the two populations. You will
then use your data and information about the lakes to draw conclusions
about the possible environmental factors affecting the evolution of pelvis
morphology.
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SCIN130 Lab 4: Stickleback Evolution, Part 2
Specific Lab Instructions
Name:
Date:
Return to: The Virtual Stickleback Evolution Lab
You are going to perform Experiment 2 for the Stickleback lab this week.
Begin with Tutorial 2. When you are comfortable scoring a pelvis in fossil
fish, you may move on (Note: it is a little more difficult in fossils than live
fish, so you may want to spend a little time here).
1. What score would you assign to a fossil specimen that has only one
pelvic spine visible? Complete
2. A stickleback fossil may show no signs of pelvic structures. What
are possible sources of error associated with scoring the pelvis of
such a fossil as “absent”?
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SCIN130 Lab 4: Stickleback Evolution, Part 2
The possible source of error in scoring a fossil with no signs of
fossil structures as absent include loss of pelvic parts due to
natural causes, damage by decay, rock decay, as well as physical
processes. However, to control for these errors, the other skeleton
of the stickleback fish is checked to see whether it is missing some
parts. If the other skeleton is intact, then the score can be absent.
When you feel you have mastered scoring fossils, you may move on to
Experiment 2.
1. In your own words describe the overall objective of Experiment 2
and explain what the data you collect will allow you to estimate.
To establish the rate of evolution of pelvic reduction by examining
pelvic structures of stickleback fish populations that lived
thousands of years ago.
2. What is one type of information that researchers can gain from
studying fossils that they cannot obtain from living populations?
By studying the fossils, researchers can calculate the rate at which
evolution of a certain trait occurred, which is not possible with
studying living populations.
Begin the experiment in the window on the left. Complete Part 1:
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SCIN130 Lab 4: Stickleback Evolution, Part 2
Preparing Fossils (click on the bench to get started).
3. You will collect data on pelvic structures using fossils from rock
layers 2 and 5. Approximately how many years of deposition
separate these two layers?
Nine thousand years of depos...