Sierra concludes her essay by writing, "In conclusion, one’s instincts can be strong." How can Sierra revise her conclusion to make it stronger? In conclusion, one’s natural instincts can be strong, and this is particularly true for Buck.

We are all ruled by natural instincts, and these instincts are often so powerful for Buck that they cannot be ignored.

Although Buck tries desperately to ignore his natural instincts, he is wholly unsuccessful.

Buck’s natural instincts cannot be denied even though he is content living within civilization.