CSI: BABOONLAND
Case: The “Orphaned” Baboon
Case Information:
As described in the introduction, Vibrant lost his mother when he was about 6 months old. He would not have
survived without the care of an adult male who turned out to be Vibrant's actual father.
Your assignment:
The lab has provided you with locus measurements of Vibrant, and his mother, Vixen. The lab also measured
the same loci for 9 male baboons, any of whom may be Vibrant’s father. Given the loci measurements below,
can you identify Vibrant’s father?
Hint: You may want to begin by determining which lengths Vibrant has that MUST have come from his father. Mark
those bands by coloring them in with your pencil, then check to see which males have all of those same bands.
Case Report
1) Based on Locus A alone, which baboons could be Vibrant’s father?
2) Who is most likely to be Vibrant’s father? How do you know?
3) Using your answer from Number 2, can you tell which of Vibrant’s bands in Locus E came from his mother?
Case: Unidentified Dead Body
Case Information: On March 14, 2009, the observers in the field found a baboon corpse on the savannah,
killed by Maasai villagers who were concerned about baboons eating their goats. Because of decomposition
and scavenging predators, the observers were not able to positively identify the corpse, but they thought the
body looked somewhat like a female named Eclipse. They collected muscle and skin samples to send to the
lab. The next day, while observing a group of baboons near where they found the body, the team saw Eclipse
alive and well, but Drill, Edgy, Rispa, and Yaya were all missing. Thanks to earlier sample collections, you have
DNA for all of these individuals.
Your assignment: Identify the dead body, using the DNA samples you already had for the missing individuals,
and DNA you extracted from the unidentified body's muscle. Look carefully—some of these missing
individuals are sisters or cousins, and will have many loci in common.
Hint: You're not matching to parents this time—you're
trying to find an exact match between the found dead
body and one of these individuals. For most loci, more
than one individual matches with the unknown, but only
one individual matches with the unknown in every case.
It will probably be helpful to use a pencil and fill in the
bands that match at each locus.
Case Report
1) Whose body did the observers find?
2) Instead of all six loci, suppose we only
looked at Loci A and B. Would we be able
to identify the body?
3) Using only Loci A and B, which individuals
match the unknown body?
4) Some loci give enough information that with only that one locus, you can identify the body. Which loci
do this?
Case: Too many children
Case Information: One of the baboon groups includes three young males named Deo, Hagrid, and
Hosana. The three of them spend a lot of time playing, running, and jumping through trees, so when
the observers want to collect fecal samples to send to the lab, it can be difficult for the observers to
keep track of which fecal samples came from whom. You have received and extracted DNA from
samples that the observers collected for each of these individuals. When you used the DNA for locus
measurements, you saw evidence that the team made some mistakes.
You have 2 samples that say they're from Hagrid, 2 from Deo, and 1 from Hosana. These are the only
samples you've ever received from these individuals, so you don't have any other samples from them
that you know you can trust. However, you do have DNA from all three of their mothers.
Your assignment: Using the mothers of Deo, Hagrid, and Hosana as a guide, figure out which of each of
the unknown samples belongs to each of the three sons.
Hint: To identify all of these questionable
samples, you'll need to compare them to
each of the three mothers, not just the
mother in the same box.
Again, using a pencil to match an
unknown's bands to the mother's will
probably make it easier to compare
samples. You may even want to use
multiple colors; make all bands that
match Deo's mom one color, bands
matching Hagrid's mom another color,
and bands that match Hosana's mom a
third color. Be careful, though: some
bands can match more than one mother.
Case Report
1) At how many loci does "Deo #1"
match each of the three mothers?
2) Using your answers from #1, who must be the mother of "Deo #1"?
3) Which individual is the true source for each of these samples?
"Deo" #1:
__________________
"Deo" #2:
____________________
"Hagrid" #1:
__________________
"Hagrid" #2:
____________________
"Hosana":
__________________
KEY
The "Orphaned" Baboon
1) Orbit, Mlozi, Piston,
Aman, Vipi
2) Mlozi. He is the
only male that has an allele
matching every one of
Vibrant's non-maternal
alleles.
3) The lower (smaller)
band came from Vixen.
Unidentified Dead Body
1) Rispa
2) No
3) Rispa and Yaya
4) D, F
Too Many Children
1) Deo's Mom-6, Hagrid's Mom-3, Hosana's Mom-2
2) Deo's Mom
3) "Deo" #1=Deo. "Deo" #2=Hagrid. "Hagrid" #1=Deo. "Hagrid" #2=Hagrid. "Hosana"=Hagrid. None
from Hosana.