Final Report

Final report: West Bloomfield High School, West Bloomfield, Mi

The most important thing we learned from this activity was not to take things for granted! We studied dominant and recessive traits as part of our lessons on genetics. But we did not probe deep enough in the analysis of the data to actually apply what we learned. For example, we "heard" that dominant traits tend to show up more frequently. Therefore, we asssumed that free earlobes, white forelock, etc were dominant traits because most people in the data showed these expressions. We even calculated ratios of free:attached earlobes and got a 2.4:1 ratio. We expected a 3:1 ratio. We were stumped and initially jumped to the conclusion that the data were bad. But our teacher then told us which expressions were actually dominant and recessive and asked us if we needed to re-define our terms dominant and recessive! This stumped us at first. But after group discussion, we decided that a dominant trait only shows up most often when the parental genotypes are both hybrid. Since we did not know the parental genotypes in this activity, we could not make conclusions on which expression was dominant here. Then, we discussed natural selection in our study of evolution, and decided that the expression of a trait that showed up most often was probably the one that was most adaptive, not necessarily dominant! We learned a good lesson. Analyzing this data, while time-consuming and sometimes difficult, was still fun.