Before she was a successful novelist, Barbara Kingsolver was a scientist. Before fans fell for her beloved debut “The Bean Trees,” about an impoverished Kentucky woman who finds a new life in the Southwest, before “The Poisonwood Bible” and its troubled missionary family earned her a Pulitzer Prize nomination, Kingsolver earned a degree in biology. Her love for and knowledge of the mysteries of nature shape her latest novel in unexpected, wonderful ways.

Set in Appalachia, the terrific “Flight Behavior” examines how the ebb and flow of the natural world plays out against the lives of the people entwined with it. Never one to shy away from controversy, Kingsolver takes on the thorny subject of climate change. You expect her to come down firmly on the side of science, and she does, but her empathy is more wide-ranging than you might imagine.

She grew up in Kentucky and lives in southern Appalachia (she wrote “Animal, Vegetable, Miracle” about eating only homegrown food there for a year). She understands the motivations and desires of rural communities ravaged by economic downfall.

In the middle of this conflict stands restless young mother Dellarobia Turnbow, who has danced the rural poor-girl two-step and found it wanting. Orphaned and pregnant at 17, she married her kind but plodding high school beau. One miscarriage and two children later, she’s stuck on a sheep farm, dreams of college dashed, lonely and unhappy and prone to distracting herself from her boredom and misery with daydreams about other men.

As the book opens, an obsessed Dellarobia is on her way to a clandestine meeting in the turkey-hunting shack high in the hills above the farm. But on the verge of throwing away marriage vows, respectability and honor, she is stopped by an amazing sight. “The forest blazed with its own internal flame. ...The sparks spiraled upward in swirls like funnel clouds.”

Stunned, Dellarobia turns home. But her encounter with the phenomenon — not supernatural fire but Monarch butterflies that have inexplicably stopped for the winter in the hills of Tennessee instead of their usual Mexican habitat — is far from over. The pastor suggests their presence is a miracle. Her mother-in-law agrees and starts leading sightseers on tours of their land. Her husband and father-in-law, sinking under the threat of a balloon loan payment coming due, have already agreed to sell the trees to a logging company.

Dellarobia’s transformation truly begins when a scientific team sets up shop next to the Turnbows’ barn. The intriguing Ovid Byron — handsome, intelligent, with a lilting Caribbean accent Dellarobia can’t get out of her head — breaks the bad news: The butterflies aren’t a miracle but an aberration, a sign that something has gone terribly wrong. Turns out nature is just as dangerous as man — a bad cold spell can kill the butterflies — and while Dellarobia nervously awaits the end of this long, complicated winter, Kingsolver plucks our emotions with the skill of a virtuoso.

The butterflies’ fates take on epic proportion. “People had to manage terrible truths,” Dellarobia knows, and so we brace ourselves for tragedy, just like the characters in this marvelous book. They’re flawed, compassionate, capable of great kindnesses and possessing of hidden depths. But guess what? Turns out they can soar, too.