So far, I’ve learned two things from this project: (1) that children will work tirelessly to answer a compelling question, and (2) any “bug” in a computer program will immediately become clear. With regard to the first issue, science lab time has recently centered around using the “new and improved” computer program that I developed over winter break, with students in grades 2-5 working diligently to solve the mystery of how our turtles are related.
We originally amplified 12 different loci (positions on individual chromosomes), in order to determine the length of microsatellites in all of our turtles, and since each baby received half its DNA from its mother and another half from its father, comparison of loci between turtles should provide a clue as to how these turtles are related… provided that there enough variations (alleles) to differentiate between individuals. If every turtle had a repeating region of TATGTATG… that went on for 238 letters, for example, we wouldn’t be able to use that locus to tell which turtle is which.
Results from one locus, which we have been calling Locus 12, unfortunately did not provide the information we’d hoped, but the other 11 have provided usable data. In fact, these 11 loci appear to be all we need to match up turtles with their parents (or connect with relatives), because in the turtles we’ve tried so far, we can narrow each of our younger turtles to one mother and one father.
As the second image above shows, students are engaged, eager, and diligent about writing down their discoveries. Nothing could be more fulfilling, especially because that’s been our vision for “Teacher Turtles” from the start. Several students are even continuing the work at home, although the current program (through Scratch) is only accessible through a desktop or laptop computer. Eventually, I might have to code this into a mobile app!
Here is the information we’ve gathered so far:
Yedlin is also the mother of Coquí and Poobles. They also match up with Boxy, who must be their father. As suspected, the two of them are brothers. Dot Dot Dash also matches up with Yedlin and Boxy, so we have three full brothers right here! Tiny also matches with Yedlin and Boxy, so it is related to the three brothers, although hatched several years apart.
Shelly Storm also matches with Boxy on all but one locus (Locus 6). This might be due to mislabeling, or incorrect data entry, because all of the other ten loci work fine! This makes another sibling for Coquí, Poobles, Dot Dot Dash, and Tiny.
Pickle also appears to have several offspring, and the following turtles have a microsatellite match: Antonia (all matches except Locus 6), Star, Lovisimo, Opportunity, and Squid Nugget. The father of all of these same turtles appears to be Mr. Putty.
Of course, as mentioned earlier, students are still finding problems when they try to use certain turtles with the Scratch program. I guess that is to be expected, but we’re working our way through! Maybe we’ve made a few mistakes with the coding, although I doubt that any program works well the first time around. That’s why it’s great to have “beta testers” as good as the students at Riverside Elementary School!
We are making lots of progress, and within the next week, we’ll start putting together a family tree!