New study finds genes related to the enormous size of whales
Scientists have long wondered about the mystery of how whales got so big. A new study suggests some answers.
Whales are ocean animals. Fin, bowhead, gray, humpback, and sperm whales are the largest animals living today. In fact, the blue whale is the largest animal that ever lived, bigger than any dinosaur.
the recent study by researchers in Brazil found that four genes appear to play an important role in the enormous size of whales, a condition known as gigantism. The researchers said the four genes appear to have produced large size while alleviating problems associated with it, such as cancer risk and decreased reproductive capacity.
Whales are part of the cetacean family of marine animals, which includes dolphins and porpoises. Scientists believe the family developed 50 million years ago from animals such as wolves, but it is also related to today’s cows, pigs, sheep, and similar animals.
Mariana Nery, a genetics expert at the University of Campinas (UNICAMP) in Brazil, was the lead author of the report. She appeared in the post. scientific reports. Nery said his team conducted the first study of gigantism in whales at the molecular level. She said: “Body size is a complex result of many genes, pathways, and physical and ecological processes.”
The study looked at seven types of whales that grow larger than 10 meters. Six of them are toothless animals. Instead, they have structures called baleen in their mouths that trap very small animals. The seventh species studied was the sperm whale, which has large teeth for feeding on giant squids and marine animals.
Whales can reach enormous sizes. Humpback and right whales can reach 15 meters in length; Greenland sperm whales and whales, 18 meters; the fin whale can reach 24 meters, and the largest, the blue whale, has been measured at 30 meters.
The researchers studied several genes related to increased body size in other animals. They found four genes that seemed to be important in the development of whales.
One of the genes is GHSR. Participates in the release of growth. hormone from the pituitary gland, a part of the body that releases important chemicals. Growth hormone can cause hunger and can control metabolism and fat growth. The gene also controls cell division.
A second gene is called IGFBP7. This gene is involved in cell growth and division. There is evidence that this gene works to suppress cancer in many parts of the body, including the prostate, breast, lung, colon, and rectum.
NCAPG is a gene associated with growth in humans, horses, cattle, pigs, and chickens. It can cause size and weight gain and affects the life of cells.
The PLAG1 gene is associated with body growth in cows, pigs, and sheep. It is involved in the growth of embryos and cell survival.
The study also suggests that genes such as GHSR and IGFBP7, which are associated with large size, could also control cell development and suppress cancer. The large size in nature is linked to a shorter lifespan. But huge whales live long lives. The humpback whale can reach 50 years of age. The blue whale can reach 90 and, the study points out, the bowhead whale is the longest-lived mammal known, reaching 200 years.
Felipe Andre Silva was the main writer of the study. He worked on the research while earning his master’s degree in genetics and molecular biology.
He said that gigantism in whales appeared relatively recently, about 5 million years ago. “Before there were large animals… but these were exceptions, and most cetaceans did not live through 10 meters long,” he said.
Silva told the Reuters news agency: “Gigantism can bring advantages as a lower probability of being predated about and a greater change of obtaining food.”
Nery said a lot can be learned about the development or evolution of whales over long periods of time. She said: “These animals can teach us a lot about the evolutionary process itself.” And whales are still popular and interesting to many people and gain a lot of attention. Nery added: “The evolution of cetaceans is a fantastic history…”
I’m Mario Ritter, Jr. and I’m Caty Weaver.
Mario Ritter, Jr. adapted this report for VOA Learning English from the Associated Press and other sources.
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words in this story
hormone –v. a substance produced by the body that influences the growth, development, and function of organs
metabolism –v. the processes essential to life by which complex substances in the cells of living things are built or broken down
live through –v. to become bigger or larger than something
advantage -north. a desirable or good quality
prey –v. drink and eat something hunted
obtain –v. obtain or gain something through effort
fantastic –adj. extremely good, usual or strange
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