Artificial Selection Experiment

Abstract: In this experiment, our group was interested to see the effects of artificial selection on the evolution of two generations of Arabidopsis thaliana. We observed such effects by using the process of selecting for the inheritable trait of height in short stemmed and long stemmed plants as the basis of our experiment and using the Arabidopsis thaliana which is small and known to grow very rapidly. We observed, pollinated, and maintained the control plants by giving them the proper life cycle in order to grow and manipulated the environment the plants went through in order to mimic the natural seasons and temperatures a plant usually goes through. After the initial growth period, we then performed artificial selection by cross-pollinating

The F1 offspring of short plants had an average height of 36.3 cm whereas the long plants had an average height of 38.5 cm.

Introduction: Evolution is driven by many forces and artificial selection is one of them. Natural selection arises from differential reproduction; that is, the environment plays a role in which organisms survive and reproduce most successfully. Those that do are more likely to pass their genes onto a new generation. In artificial selection, though, humans decide which organisms reproduce and, therefore, control what kind of offspring they have. Artificial selection forces evolution or changes in a species to occur in a certain way that satisfies the wants or needs of humans(Campbell, N., & Reece, J. 445). As opposed to natural selection,

When measuring the plants, there were tall ones in the short-stemmed side and short plants in the tall-stemmed side. In addition to this, there was only a 2.2 cm difference in plant length between the tall and the short sides. A possible explanation could be polygenic inheritance, an additive effect of two or more genes on a single phenotypic character(Campbell, N., & Reece, J. 263). There is a possibility that there are multiple alleles that could control the characteristic of height. Thus, variations of height within the “short” side and “tall” side would occur. The short amount of time to perform this experiment also could have a played a role for the turn out of the results. If the experiment was to be extended for a couple more generations, more conclusive results could be drawn to fully see the effect of artificial selection. The chance for human error in this experiment was very high as an error that may have affected our results is that our group didn’t use the same people that measured the P generation to measure the F1 plants, thus creating confusion on which side was “side 1” and “side 2”. Another error that may have affected our results was that the people measuring the plants were not certain whether they measured the same plant twice and may have lead to redundancy in data. An improvement would be to better keep track of the measurements and