There is little variation within each population, and
the stickleback in Frog Lake
are more similar to marine and sea-run stickleback. 4. Bear Paw Lake and Frog Lake were likely populated by the same sea-run population of stickleback at the end of the last ice age.
Why are the stickleback fish in Frog lake more similar to ocean and sea-run stickleback than they are to those in Bear Paw lake?
Stickleback fish in Frog Lake are more similar to ocean and sea-run stickleback than they are to the stickleback fish in Bear Paw Lake
because they have complete pelvises
. Whereas stickleback in Bear Paw Lake have reduced or absent pelvises.
In what ways do the fish in Bear Paw lake differ from those in the marine habitat?
difference is that
Bear Paw Lake is completely enclosed and does not drain at the surface
. This means that predatory fish cannot readily enter the lake. On the other hand, Frog Lake is connected to the water system by a small stream, which allows predatory fish to gain access to the lake.
Why did you compare pelvic structures of stickleback populations from two different lakes?
In the virtual lab, why did you compare pelvic structures of stickleback populations from two different lakes?
To have a larger number of specimens to score, increasing the accuracy of results
. To compare the trait in stickleback populations living in two potentially different environments.
Why are the stickleback fish different in these lakes?
Sticklebacks started out as saltwater fish. … Over time, the lake fish
came to look quite different from their marine forefathers
. These populations are now natural laboratories for evolutionary studies. One prominent difference is the pelvic spines.
What type of stain did we use for the fish?
The fish have been stained with a dye called
Alizarin Red S
, which stains bones, in order to highlight their differences.
What does it mean to reject the null hypothesis for Bear Paw and Coyote lakes?
The probability is less than 0.05 for both lakes
. This means that the null hypothesis (i.e., your expectation of 50:50) can be rejected for Bear Paw Lake and Coyote Lake.
Why did stickleback lose its spines?
The many stickleback populations underwent disparate and parallel evolutionary changes, among them partial or complete loss of their pelvic spines. These spines are thought
to protect the fish from being devoured by predators
.
What characteristics of stickleback fish make them ideal for studying natural selection in the wild?
What characteristics of stickleback fish make them ideal for studying natural selection in the wild?
Stickleback populations are in environments with or without predators
. Heritable variation in armor directly affects the fitness of sticklebacks. Some stickleback populations are isolated in closed environments.
How were the saltwater stickleback fish able to adapt to a freshwater environment so quickly quizlet?
How do spines protect ocean stickleback fish? …
As more and more ice melted, connections between some of the lakes and the ocean were cut off
, and stickleback populations became trapped in these lakes. Because of this, they adapted to living exclusively in fresh water.
What differences did you notice in the appearances of the fish from Bear Paw Lake compared to Frog Lake?
The data suggest that
fish in Bear Paw Lake are bigger than those in Frog Lake
. The graph suggests that all fish in Bear Paw Lake lack pelvic spines and all fish in Frog Lake have pelvic spines. The data suggest that the fish in Frog Lake vary widely in pelvic structures.
What 3 things have changed in the stickleback fish over time?
In freshwater, they faced weaker but faster predators, so they lost their spines and armour and became smaller and more agile. Their
lifestyles, colour, mating habits, salt tolerance and diets
also changed.
What is another component of the armor of a stickleback fish?
Sea-run – migrate to the sea from freshwater to breed. In addition to spines, what is another component of the ‘armor’ of stickleback fish?
A row of plates running from the back of the head to the rest of the body.
Why did stickleback fish evolve?
Scientists have pinpointed mutations that may help a tiny armoured fish to evolve quickly between saltwater and freshwater forms. … In as few as ten generations — an evolutionary blink of an eye — marine sticklebacks can
swap their armoured plates and defensive spines
for a lighter, smoother freshwater form.
Why did Dr Kingsley do genetic crosses with stickleback fish?
Why did Kingsley and his team cross marine and freshwater sticklebacks?
To understand when in embryonic development the gene(s) for making a pelvis is/are active
. To test whether Pitx1 was involved in the formation of pelvic spines. To compare the Pitx1 protein-coding sequence from fish with and without pelvises.
Do sticklebacks live in the sea?
Marine three-spined sticklebacks
migrate out to sea in the winter
, returning to freshwater rivers in the spring to spawn.
