New study reveals how some snakes survive for a year without eating

We probably don't know as much about snakes as we know about them. They're not usually in front of our eyes. They seem to be from a different world. Everything about them is different. They can swallow their prey. They sit quietly in one place and wait for prey. They can go months without eating. Sometimes they don't eat anything at all for more than a year. It's incredible. For many years, experts have been unable to explain it properly. But now researchers think the door to this mystery is finally opening.

"The data was right in front of our eyes," Todd Casto, a geneticist at the University of Texas at Arlington, told Science magazine. He was not directly involved in the study. But the research team looked at the subject in depth. So what was found that had been hidden from view for so long?

Behind this story is a hormone called ghrelin. In the human body, it is mainly secreted from the stomach and tells the brain, ‘Now is the time to eat.’ It is often called the ‘hunger hormone’. At one time, scientists thought that this hormone might be at the root of problems such as diabetes, obesity or overeating. But later it turned out that the matter is so complex that simply stopping ghrelin does not reduce hunger or weight. As a result, researchers’ knowledge about its function was incomplete.

In this new study, scientists decided to search outside mammals. They analyzed the genomes of 112 reptile species. These include snakes, chameleons, turtles, lizards and many other animals. This search revealed surprising information. It was found that 32 types of snakes, 4 types of chameleons and two types of toadhead agama have almost completely lost the gene necessary for producing ghrelin.

Rui Resende Pinto, an evolutionary biologist at the University of Porto in Portugal and co-author of the study, said that in some snakes, only small fragments of the ghrelin gene were found. In some, the gene was completely absent. In others, it was so distorted that it could not be used to produce a useful hormone. This diverse picture suggests that the gene was lost at different times in multiple reptile groups. It may even have happened more than once in snakes.

Ghrelin is not the only missing element. A key enzyme required for its function, MBOAAT4, is also absent in these extremely food-tolerant animals. According to the researchers, the absence of these two genes is not a coincidence. Rather, it is the result of physiological and behavioral adaptations through which animals like snakes have learned to survive, since their chances of finding prey are uncertain.

In humans and other mammals, ghrelin tells the body to burn fat, build energy, and find food when it is hungry. But snakes, some chameleons, and agama lizards have a different strategy. They follow a ‘sit-and-wait’ or sit-and-wait hunting strategy. This means they sit quietly in one place until the prey comes to them.

In this type of hunting method, getting food is uncertain. So these animals have developed a strategy that minimizes their energy expenditure during rest. This is precisely why the gene for the ghrelin hormone has been lost. According to researchers, as a result, the body’s metabolic rate during fasting and digestion works in the opposite way compared to mammals. This is where that incredible ability comes from. They get the strength to survive without eating for months, even more than a year.

Researchers find this discovery very surprising. This could be an important step towards understanding how ghrelin works not only in snakes, but also in other animals.