If Rachel Carson hadn't written her most important and best-known work, “Silent Spring,” she would have still had a life and career like few others.

When that book is added in, though, she stands as one of the most important scientific figures of the mid-20th century, who nearly single-handedly invented modern environmentalism and made the entire world question — if not entirely abandon — the ideal of humans totally dominating and controlling the natural world.

Carson was born in Springdale, in Allegheny County, in 1907, about 20 miles north of Pittsburgh and 30 miles south of Butler. Her family had purchased a four-room farmhouse on 65 acres in 1901 and had plans to subdivide and sell the land to make money. That never came to pass, as the family faced persistent financial difficulties.

Money problems were a regular occurrence for the Carson family. They delayed Carson's graduate studies at Johns Hopkins University in the late 1920s, and in 1934, after she'd earned a master's degree in zoology and was progressing toward a Ph.D., the Great Depression forced her to leave that program to find full-time work.

Carson had started writing around age 8, and by 10 she'd had stories published in magazines. When she enrolled in Pennsylvania Women's College — now Chatham University — she was originally an English major, before switching to biology. She also wrote for publications at the school.

It was that experience that helped land her a temporary job writing radio scripts for a weekly program called “Romance Under the Waters” that the U.S. Bureau of Fisheries hoped would spark public interest.

Carson's scripts were so successful at that goal her supervisor offered another assignment and a larger idea. The assignment was for a public brochure about the bureau. The larger idea: Carson should join the department permanently.

In 1936, she became a junior aquatic biologist. Carson's supervisor rejected her first draft of the brochure, though — he thought it was too good for that purpose.

Instead, it became the basis for “Undersea,” which was published in 1937 in the Atlantic Monthly and would serve as the basis for her first book, 1941's “Under the Sea Wind: A Naturalist's Picture of Ocean Life.”

The book was well-reviewed but didn't sell well.

It wasn't until 10 years later, with the publication of “The Sea Around Us” that Carson found literary success. That book was on the New York Times Bestseller List for 86 weeks and brought attention to her first book, as well.

The reception of “The Sea Around Us” meant Carson could write full-time, and in 1955 she completed her trilogy of books on the sea with “The Edge of the Sea,” which examines the ecology of the Eastern Seaboard of the United States.

Dichlorodiphenyltrichloroethane, known as DDT, was first synthesized in the late 19th century, but it wasn't until 1939 that Paul Hermann Mueller, a Swiss scientist, discovered that it killed mosquitoes. The importance of that ability was immediately clear, and within just a few years, counties were using the chemical to control mosquito populations.

Mueller's discovery led to him receiving the Nobel Prize in Medicine in 1948.

By 1945, DDT was being used on farms in the United States, but from very early on, people raised concerns.

A Michigan doctor named Bradley Robinson wrote about his worries in 1947.

“Perhaps the greatest danger from D.D.T. is that its extensive use in farm areas is most likely to upset the natural balances, not only killing beneficial insects in great number but by bringing about the death of fish, birds, and other forms of wild life either by their feeding on insects killed by D.D.T. or directly by ingesting the poison,” he wrote.

Carson, through her position in the Bureau of Fisheries, was aware of the concerns. In the late 1950s, a public outcry about DDT spraying and a letter from a friend noting the death of birds on her property after it was sprayed with DDT helped push Carson toward writing about DDT.

While “Silent Spring,” which Carson worked on between the late 1950s and its publication in 1962, addresses DDT, it's about more than just one pesticide. In fact, Carson rejected that very word in the book.

She pointed out that the effects of chemicals like DDT are hardly ever limited to just creatures that humans consider pests. Instead, they can have ripple effects throughout an entire ecosystem.

One issue she pointed out was bioaccumulation — when a substance builds up in an organism faster than the organism can clear that substance from its system. With chemicals like DDT, that can mean animals that eat things that have been sprayed with DDT start seeing increasing levels of the chemical in their system, causing spiraling health problems.

The book also warned about another possible consequence: increased resistance. That worry has come to pass, with countries that still use DDT for mosquito control seeing decreasing effectiveness over time.

“No responsible person contends that insect-borne disease should be ignored,” Carson wrote in “Silent Spring.” “The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse. The world has heard much of the triumphant war against disease through the control of insect vectors of infection, but it has heard little of the other side of the story — the defeats, the short-lived triumphs that now strongly support the alarming view that the insect enemy has been made actually stronger by our efforts. Even worse, we may have destroyed our very means of fighting.”

Much of the book questions not just the specific methods and chemicals used to try and reduce the insect population, but the underlying assumptions about humans controlling the world around them.

That, almost inevitably, led to strong criticism, especially from those employed by chemical manufacturers. Despite those critics, and despite threats of legal action, “Silent Spring” was a Book of the Month selection and would sell 2 million copies.

Carson didn’t get to see much of the long-term impact of her work. She was diagnosed with breast cancer while working on the book and it would claim her life in 1964.

But her final and most famous book opened a conversation that's still happening now about how science, progress and the natural world can and should interact.