hi guys i'm kyla and i'm alex and today
we are going to be doing the natural
selection in isopods lab let's begin by
setting up the arena
to set up the arena you first want to
lay out some paper towel on the tray
make sure to fold the edges of the paper
towel so that it does not drape over the
sides of the tray next you need to
dampen the arena if there's too much
water blot the paper towel to take off
the excess water so that there are no
pools of water in your arena
next you want to set you want to set up
the refuge on one side of the arena to
do this wrap some tinfoil over the
edge the next step is to transfer 12
isopods from the main colony into the
holding container the next step is to
transfer the isopods from the holding
container to the end of the arena
opposite from the foil refuge ensuring
that the isopods remain trapped by the
cup until you are ready to start the
experiment you may need to also gently
tap the bottom of the cup to knock down
any isopods that are clinging to the
bottom or the sides of the cup allowed
the next step is to choose one group
member to act as the predator today it
will be Alex and when you before you're
ready to start make sure you have your
timer and your victim container ready
when you're ready to start one person
will release the isopods and the
predator will catch as many isopods in
the 30 seconds and transfer them to the
victim container start the timer even
though you want to be as fast as
possible be careful not to harm the
isopods
after the 30 seconds of predation is
over you can now transfer any isopods
that are remaining in the arena
into the survivor container
to avoid experimental bias choose one
group member to record the group data
the recorder will first transfer all
isopods to number wells in a 12 well
plate make sure that you keep track of
the number for each victim and survivor
try to randomize numbering and do not
tell the rest of the group whether a
particular number isopod is a victim or
a survivor this information will be only
revealed to rest the group after the
length measurements and speed trials
have been completed
use a ruler to measure each isopod in
each numbered well and record the length
in millimeters in well number one the
isopod is nine millimeters while number
two the isopod is six millimeters
the next step is to set up the racetrack
in a similar way that you set up the
arena so first put the cloth in and
dampen it making sure that it is not too
wet again if you do have excess water
just blot it with some paper towel
once you've gotten rid of the excess
water you then want to put foil on one
end of the racetrack
to serve as a refuge transfer the chosen
isopod to the open track allow a
short recovery time of 5 to 10 seconds
then you want to start the timer and
measure the distance the isopod runs in
10 seconds
to do this trace the path that the isopod runs on a piece of paper beside
the track do not write on the lab bench
the next step is to fit a piece of
string to the line that you have just
drawn
once you've done that grab the two ends
and lay out the string so that you can
measure the distance that the isopod ran
in the ten seconds in this case it's
going to be 26.5 centimeters
after you have measured the distance the
isopod ran the next step would be to
write down the distance beside the
corresponding isopod and then you will
want to calculate the speed
the last and final step of this
experiment is the cleanup first make
sure that any isopods left at your bench
is returned to the holding tank you then
want to discard damp paper towel dry the
arena and the racetrack
fold the aluminum foil and return all
equipment and containers to the arena
tray leave it the way you found it
