On land, stories of shark encounters have been embellished and exaggerated. Combined with the fact that sharks occasionally – very rarely – bite humans, people have been conditioned for centuries to imagine horrific situations at sea.

In 1974, Peter Benchley’s best-seller Jaws sparked this fear into a wildfire that spread around the world. The book sold over 5 million copies in the US within a year, and was soon followed by Steven Spielberg’s film in 1975, which became the highest-grossing film in history at the time.

Almost all viewers were convinced by the idea, vividly portrayed in the film and its sequels, that sharks are vicious, vengeful creatures that roam the coastal waters in search of unsuspecting swimmers.

But Jaws also sparked widespread interest in better understanding sharks.

Previously, shark research was largely the esoteric domain of a handful of academic specialists. Thanks to the interest sparked by Jaws, we now know that there are many more species of sharks than scientists knew in 1974, and that sharks do more interesting things than researchers ever expected. Benchley himself became an avid spokesman for shark and marine conservation.

In my own 30-year career studying sharks and their close relatives, rays, I’ve seen attitudes toward sharks evolve and interest in understanding sharks grow enormously. Here’s how things have changed.

SWIMMING INTO THE SPOTLIGHT

Before the mid-1970s, much of our knowledge of sharks came from people who went to sea. In 1958, the U.S. Navy created the International Shark Attack File—the world’s only scientifically documented, comprehensive database of all known shark attacks—to reduce the risk of war for sailors stranded at sea after their ship sank.

Today, the file is managed by the Florida Museum of Natural History and the American Elasmobranch Society, a professional organization for shark researchers dedicated to educating the public about shark-human interactions and ways to reduce the risk of shark bites.

In 1962, Jack Casey, a pioneer of modern shark research, initiated the Cooperative Shark Tagging Program. This initiative, which continues to this day, relied on commercial fishermen in the Atlantic to report and return tags they found on sharks so that government scientists could calculate how far the sharks had moved after being tagged.

After Jaws, shark research quickly went mainstream. In 1982, the American Elasmobranch Society was founded. Graduate students lined up to study shark behavior, and the number of shark studies published skyrocketed.

As interest in extreme sports such as surfing, parasailing and scuba diving grew, so did field research on sharks. Electronic tags allowed researchers to monitor sharks’ movements in real time, and DNA sequencing technologies offered inexpensive ways to determine how different species were related to each other, what they ate and how populations were structured.

This interest also had a sensational side, which manifested itself in the launch of Shark Week on the Discovery Channel in 1988. This annual block of programming, ostensibly designed to educate the public about shark biology and counter negative reporting about sharks, was a commercial venture that exploited the tension between people’s deep-seated fear of sharks and their desire to understand what drives these animals.

Shark Week presented made-for-television stories that focused on fictional scientific research projects. The show was hugely successful and continues to be so to this day, despite criticism from some researchers who call it a major source of misinformation about sharks and shark research.

PHYSICAL, SOCIAL AND GENETIC KNOWLEDGE

Contrary to the long-held notion that sharks are mindless killers, they exhibit a wide range of characteristics and behaviors. The velvet-bellied lanternshark, for example, communicates through flashes of light from organs on the sides of its body. Female hammerhead sharks can clone perfect replicas of themselves without the need for male sperm.

Sharks possess the most sensitive electrical detectors yet discovered in nature – networks of pores and nerves in their heads called ampullae of Lorenzini, named after the Italian scientist Stefano Lorenzini who first described these features in the 17th century. Sharks use these networks to navigate in the open ocean, using the Earth’s magnetic field as a guide.

Another interesting discovery is that some shark species, including makos and blue sharks, are segregated by both sex and size. In these species, cohorts of males and females of different sizes are often found in separate groups. This discovery suggests that some sharks may have social hierarchies, as seen in some primates and ungulates.

Genetic studies have helped researchers answer questions such as why some sharks have heads shaped like hammers or shovels. They have also shown that sharks have the lowest mutation rate of any vertebrate. This is notable because mutations are the raw material of evolution: the higher the mutation rate, the better a species can adapt to environmental changes.

However, sharks have been around for 400 million years and have experienced some of the most extreme environmental changes on Earth. It is not yet clear how they have been able to survive so successfully despite such a low mutation rate.

The outstanding type

Great white sharks, the central species of Jaws, attract a great deal of public interest, although much is still unknown about them. They can live up to 70 years and swim thousands of miles each year. Great white sharks in the western North Atlantic typically migrate north to south between Canada and the Gulf of Mexico; great white sharks on the U.S. West Coast migrate east to west between California and the central Pacific.

We now know that juvenile great white sharks feed almost exclusively on fish and stingrays, and only begin to eat seals and other marine mammals when they are teenagers and about 12 feet (3.6 meters) long. Most confirmed great white shark bites on humans appear to be from animals between 12 and 15 feet (3.6 and 4.5 meters) long. This supports the theory that almost all great white shark bites on humans are cases of mistaken identity, with humans resembling the seals the sharks hunt.

STILL IN THE WATER

Although Jaws has had a far-reaching cultural impact, it has not stopped surfers and swimmers from enjoying the ocean. Data from the International Shark Attack File on confirmed, unprovoked bites by great white sharks from the 1960s to the present show a steady increase, although the number of incidents per year is quite low. This pattern is consistent with the growing number of people pursuing recreational activities along the coasts.

Since 1960, 363 unprovoked bites by great white sharks have been confirmed worldwide. 73 of these were fatal. The World Health Organization estimates that 236,000 people drown each year. This equates to around 15 million drowning deaths in the same period.

Put another way, people are about 200,000 times more likely to drown than to die from a great white shark bite. And in fact, surfers are more likely to die in a car accident on their way to the beach than they are to be bitten by a shark.