Problem
You are the research head of the International Space Agency's Intergalactic Evolution and Ecology Unit. On Earth2, the gillyweed plant, which is extremely valuable are failing. You know from previous studies that increasing CO2 stimulates growth of some plant species but not all plant species, and so you hypothesize increasing CO2 levels affects gillyweed growth. Alternatively, a farmer your graduate students know thinks that improved soil fertility (via fertilizers) may help as last year after adding fertilizer they had a good crop of gillyweed. Your graduate students on Earth2 design and carry out an experiment; they present their findings to you at the end of the year.
Experiment:
I. Plant 300 genetically identical gillyweed plants with the same fertilizer and randomly assign the plants to one of three different greenhouses: a. one has atmospheric ("normal") levels of CO2 b. one has lower than normal levels of CO2 c. one has higher than normal levels of CO2. 2. Grow gillyweed for two generations and measure the maximum height of each plant in each generation and greenhouse.
Results and Conclusion Your graduate students find that the average height of the gillyweed is significantly higher than old generations, however the average height of gillyweed in each of the greenhouses is not significantly different from each other. They conclude that improved soil fertility helped gillyweed growth, whereas CO2 did not have an impact on gillyweed growth.
Why do you disagree with your students' conclusion?
II. You are looking for a transitional fossil between unicorns (which live on land) and their ancestors which swam. You have discovered a fossil that could be a transitional between unicorns dwelled in terrestrial ecosystem and unicorns in aquatic. What evidence in the fossil would support your prediction of the transitional forms? In other words, how would you know that this was a transitional fossil? Provide an explanation as to how that evidence would support the hypothesis.