UNIVERSITY OF MICHIGAN
THE VIRTUAL EVOLUTION STICKLEBACK
LAB
Course: BIOL 173 BIOLOGY LAB
, THE VIRTUAL EVOLUTION STICKLEBACK
LAB
As you complete each part of the virtual lab, answer the questions below in the space provided.
INTRODUCTION
1. Define “model organism.”
Nonhuman species extensively studied to understand particular biological phenomena.
2. How do spines protect ocean stickleback fish?
Spines protect ocean sticklebacks from predatory attacks.
3. How did ancestral populations of ocean-dwelling fish come to live in freshwater lakes?
Some fish are anadromous and travel from the ocean via rivers to spawn in freshwater lakes.
4. Watch the video about pelvic reduction in freshwater stickleback. The loss of stickleback
pelvic spines is similar to the loss of which body parts in some other four-legged vertebrates?
The loss of stickleback pelvic spines is similar to the loss of legs in some other four-legged vertebrates.
5. From a researcher’s perspective, what is the benefit of having access to hundreds of postglacial lakes?
The benefit of having access to hundreds of postglacial lakes is that researchers can compare a trait in different
stickleback populations and make predictions about which environmental conditions influence the trait.
6. Watch the video with evolutionary biologist Dr. Michael Bell.
Why is the three-spine stickleback a model organism for studies in evolution? (List at least two reasons.)
The three-spine stickleback is a model organism because they are small enough, and have a short generation time.
Other reasons are that you can breed them in a lab, and do genetic crosses between vastly different looking
individuals.
7. Watch the video with Dr. David Kingsley explaining hind-limb reduction. Name two other
vertebrate animals whose evolutionary histories included the loss of hind limbs.
Two other vertebrate animals whose histories included the loss of hind limbs are snakes and whales.
OVERVIEW
1. Click on the interactive stickleback fish. Describe where its spines are located.
Behind its head and on its stomach below its fins
2. What is the difference between marine, sea-run, and freshwater stickleback fish populations? Be specific.
Marine stickleback populations live and breed strictly in the ocean. Sea-run stickleback fish are
anadromous, meaning that they are born in fresh water, spend most of their lives in the ocean, and
return to fresh water to breed. Freshwater stickleback fish live entirely in fresh water.
3. Watch the video about the stickleback fish armor.
a. In addition to the spines, what is another component of the “armor” of a stickleback fish?
A row of plates running from the back of the head to the rest of the body.