Which is which?
So now we have put together a tree showing the
relationships among our baby tortoises.
Now that we have a tree (with species E labeled
as G. radiata) and we have the species grouped into
smaller groups, we can go back to our boxes and try to
put those labels on. Use the questions below to help you
put the labels on the tree.
- Which do you think are the four tortoises from
Madagascar? Why? Hint [Species B and C are in a group.
Species D and E (G. radiata)are in a group. Both of
those groups fall into a bigger group totaling 4
species, one of which we know is from Madagascar.]
- Look at the species names on the labels. Can you
group the four Madagascar labels into two groups like
the ones on the tree? Can you correctly label species D?
Hint [What is the genus name for E? Don't worry about
which is which within the Pyxis group.]
- What species do you think would be most
closely related the species from Madagascar? Hint [Look
at the map for help.]
- Look at the species names of the two tortoises
you have left, can those help you determine which one
should be more closely related. Hint [Is one genus
unlike the others?]
- The only thing we are missing is to determine
which one is which within the Pyxis genus. Fortunately,
you would be sending both Pyxis specimens to the same
person in Western Madagascar, and he is confident that
in a few weeks he will be able to tell them apart.
Now that you have correctly labeled the tortoises, you can
rest easy about having done your job and returned them to their
proper home. But this is not the end of where we can go with
this genetic information. For someone who is interested in
Madagascar's biodiversity and how everything arrived on the
island, there are more interesting questions we can answer.