Passage Summary: We have the power to change the rules of science, but we shouldn't do it without first checking if the benefits are worth the high price and the potential damage to the field itself.

Conclusion: Decisions about changing how science is conducted and regulated must be made by determining if the changes are justified in light of their costs.

Reasoning: While significant changes to scientific practice are possible, such as ending animal research or restricting DNA work, these interventions are expensive and fundamentally alter the nature of science.

Analysis: To identify the conclusion, look for the statement that the rest of the text is trying to prove. The author starts with a general claim about the need to weigh costs and then provides specific examples—animal research, DNA, and fraud police—to illustrate what those 'costs' look like. The conclusion is the second sentence, which acts as the thesis for the entire argument. Be careful not to pick an answer that focuses only on one of the examples; the main point is the overarching principle of cost-benefit analysis.