Scientists tracking the populations of certain freshwater fish have found an increase in the female to male ratio of several smaller fish species over the last 10 years. One group of scientists have analyzed the data and hypothesized that medications in wastewater have contributed to this change in fish populations. Another group of scientists have hypothesized that this population trend is part of a cycle related to climate and ecosystem changes. If these two groups of scientists have access to the same population data, why have they formed two very different hypotheses?