Where do humans come from? The theory of evolution suggests that our ancestors were a species of tree-dwelling apes. Where did the gibbons come from? Their ancestors were a type of mammal that emerged after the dinosaurs went extinct. And where did mammals come from? They evolved from early marine fish that crawled onto land.
Thus, you might also know that all terrestrial life today originated from the ocean. Of course, some species later found it challenging to live on land and decided to evolve back into the ocean, such as dolphins and whales…
This research was conducted by the International Conservation Organization in collaboration with the Scientific and Industrial Research Organization, the Florida Museum of Natural History, the Indonesian Institute of Sciences, and the Indonesian Ministry of Marine Affairs and Fisheries. These sharks pose no threat to humans. They are also known as “epaulette sharks,” specializing in hunting small fish and invertebrates in shallow waters. Swimmers may catch a glimpse of them on coral reefs during low tide.
So, at the present moment, are there any fish evolving to transition from the ocean to land? Recently, an international research team consisting of scientists from the University of Queensland in Australia, the United States, Indonesia, and other countries conducted a 12-year study and discovered that some species of sharks near Australia and New Guinea have indeed evolved to gradually adapt to life on land. They are currently in the evolutionary phase of adapting to low tides.
They are believed to have branched off from their ancestors around 9 million years ago. The most recent species may have evolved to walk along the ocean floor about 2 million years ago. This makes them the most recently evolved sharks. This also provides humans with a completely new perspective on the evolutionary history of sharks. Sharks that use their fins to walk can also forage for food under rocks and corals. They average about 100 cm in length and primarily inhabit shallow coral reefs. Their diet consists of small fish and seagrass.
Sharks are primitive and ancient species, and perhaps due to their comfort in the ocean, fossil records indicate that more than 1,200 shark species have existed over the last 400 million years. In fact, most shark species have not evolved much, and many of them are considered living fossils.
However, this study surprised scientists by discovering that there are 9 species of epaulette sharks in the coastal waters near northern Australia and New Guinea. When the tide goes out, they use their pectoral and pelvic fins to “walk” in shallow waters and hunt prey such as crabs, shrimp, and small fish in coral reefs, gradually becoming the top predators in these shallow reefs during low tide.
At first glance, they are often imagined as lizards taking a stroll rather than a fierce shark species known for its ferocity in the ocean.
Christine Dudgeon, a scientist from the University of Queensland, Australia, stated: “The ability to withstand low-oxygen environments and walk on their fins gives this species a significant advantage over small crustaceans and mollusks.” The research team hopes that through this study, humans will understand why some animal species change and adapt over time, while others remain the same. However, at present, the development of these walking sharks is threatened by habitat destruction and overfishing.
Researchers believe that the reason these sharks can walk on fins in low-oxygen environments may be due to their isolation in a specific area millions of years ago and their evolution into a new species. Another reason could be changes in the ocean, including fluctuations in sea levels, ocean currents, and temperature changes, forcing epaulette sharks to quickly adapt to this dynamic environment. Thus, they developed “the ability to defy the sky,” becoming a nightmare for small crustaceans and mollusks.
This species of shark is relatively small, with an average length of one meter.
Of course, we humans do not need to be alarmed upon hearing that sharks are evolving to come ashore, as these sharks are relatively small, averaging about one meter in length, and pose no threat to people. Conversely, if their meat is tasty, they could easily be turned into delicacies by humans, and if unlucky, human impacts could lead to their extinction before they can fully adapt to life on land.
Or, even if their meat is not delicious, sooner or later, humans will “invite” them to zoos and laboratories. So far, humanity has evolved, and no species poses a threat to us, except for ourselves.
