Directions : In this section each item consists of six sentences that comprise a passage. The first and sixth sentences are given in the beginning as S1 and S6. The sequence of the four sentences in the middle, labelled as P, Q, R, and S, has been jumbled. You are required to find the proper sequence of the four jumbled sentences and mark your response on the Answer Sheet accordingly.

S1: Among the momentous watersheds through which human beings have passed since their appearance over 100,000 years ago, none has been more profound in its consequences than the shift to agriculture. S6: Unfortunately, such transformations disrupted delicate natural balances as humans sought enhanced control over their new modes of subsistence. P: They did this by purposefully transforming landscapes with their agricultural fields and pastures. Q: They lived much like the way in which their own hominid predecessors had lived for millions of years, as integral components of the Earth's ecosystems. R: However, with the invention of practices of agriculture, these new farmers and herders began manipulating their surroundings to an unprecedented degree. S: Before that, for countless generations, nearly all humans had lived as hunters and gatherers, dwelling together in small, stable, nomadic bands that operated in close harmony with nature.