Final answer:
The author's sentence arrangement in the paragraph highlights the accumulation of evidence for complex ocean currents, underscoring the iterative nature of scientific discovery in oceanography.
Step-by-step explanation:
At the end of the fourth paragraph, the author strategically arranges sentences in a manner that emphasizes the mounting evidence for the complexity of the ocean's currents. This strategic arrangement serves to convey the layers and scope of scientific discovery pertaining to oceans, which involve the process of continuous observation, theorizing, and verification through various kinds of evidence, such as satellite images, deep-sea sediments, and ice-core analyses. Such comprehensive detail underlines not just the abundance of evidence needed to challenge and evolve established scientific norms but also highlights how each piece of evidence contributes to a gradually increasing understanding of ocean dynamics.