Interpreting prehistoric migration patterns often relies on artifacts found at inland settlements. Such assemblages, however, disproportionately represent long-occupied sites, biasing estimates toward stability. By contrast, coastal deposits record short-lived expansions that inland surveys often miss. Shell middens and seasonal camps preserve traces of movements tied to fisheries and trade winds. Incorporating these data changes the timeline: bursts of settlement appear punctuating longer periods of local residency. The revised chronology helps explain genetic findings that suggest episodic mixing among distant groups. Rather than a steady march across continents, migration likely unfolded in fits and starts, with environmental windows enabling rapid dispersals followed by consolidation.
Which choice best describes the function of the underlined sentence in the overall structure of the text?
- Articulates the passage's central research question.
- Transitions by contrasting inland and coastal records to introduce a new line of evidence. (correct answer)
- Defines a technical term.
- Summarizes the argument's final conclusion.
Explanation: The sentence marks a contrast and shifts the discussion to coastal evidence that drives the next points. It neither states the main question (A), defines terminology (C), nor summarizes the end conclusion (D).