New Study Finds Genes Linked to Whales' Huge Size
2023-01-27
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1Scientists have wondered long on the mystery of how whales got so big.
2A new study suggests some answers.
3Whales are ocean animals.
4The fin, bowhead, gray, humpback and sperm whales are the largest animals living today.
5In fact, the blue whale is the largest animal known to have ever existed, bigger than any dinosaur.
6The recent study by researchers in Brazil found that four genes appear to play a big part in whales' huge size, a condition known as gigantism.
7The researchers said the four genes appear to have produced great size while easing the problems linked with it, such as cancer risk and lower reproductive ability.
8Whales are part of the ocean animal family called Cetaceans, which includes dolphins and porpoises.
9Scientists think the family developed 50 million years ago from animals like wolves, but is also related to today's cows, pigs, sheep and similar animals.
10Mariana Nery, a genetics expert with the University of Campinas (UNICAMP) in Brazil, was a lead writer of the report.
11It appeared in the publication Scientific Reports.
12Nery said her team has done the first study of gigantism in whales at the molecular level.
13She said, "Body size is a complex result of many genes, pathways, and physical and ecological processes."
14The study examined seven kinds of whales that grow longer than 10 meters.
15Six of them are toothless animals. Instead, they have structures called baleen in their mouths that catch very small animals.
16The seventh species studied was the sperm whale, which has large teeth to feed on giant squid and ocean animals.
17The whales can reach huge sizes.
18Humpback and right whales can reach 15 meters in length; the sperm and bowhead whales, 18 meters; the fin whale can reach 24 meters, and the biggest, the blue whale, has been measured at 30 meters.
19The researchers studied several genes linked to increased body size in other animals.
20They found four genes that appeared to be important in the development of whales.
21One of the genes is GHSR.
22It is involved in releasing growth hormone from the pituitary gland, a part of the body that releases important chemicals.
23Growth hormone can cause hunger and it can control metabolism and the growth of fat.
24The gene also controls cell division.
25A second gene is called IGFBP7. This gene is involved in cell growth and division.
26There is evidence that this gene acts to suppress cancer in many parts of the body including the prostate, breasts, lungs, colon and rectum.
27NCAPG is a gene associated with growth in humans, horses, cattle, pigs and chickens.
28It can cause size and weight gain and affects the lives of cells.
29The gene PLAG1 is associated with body growth in cows, pigs and sheep.
30It is involved in the growth of embryos and cell survival.
31The study also suggests that the genes such as GHSR and IGFBP7, which are linked to huge size, might also control cell development and suppress cancer.
32Huge size in nature is tied to shorter lifespans.
33But huge whales live long lives.
34The humpback whale can reach 50 years of age.
35The blue whale can reach 90 and, the study noted, the bowhead whale is the longest-lived mammal known, reaching 200 years of age.
36Felipe Andre Silva was lead writer of the study.
37He worked on the research while earning his master's degree in genetics and molecular biology.
38He said gigantism in whales appeared relatively recently, around 5 million years ago.
39"Before that there were animals with large sizes...but these were exceptions, and most cetaceans did not exceed 10 meters in length," he said.
40Silva told Reuters news agency: "Gigantism may bring some advantages such as a lower chance of being preyed upon and a greater change of obtaining food."
41Nery said a lot can be learned about the development, or evolution, of whales over long periods of time.
42She said, "These animals can teach us a lot about the evolutionary process itself."
43And whales remain popular and interesting to many people and gain a lot of attention.
44Nery added, "The evolution of cetaceans is a fantastic story..."
45I'm Mario Ritter, Jr. And I'm Caty Weaver.
1Scientists have wondered long on the mystery of how whales got so big. A new study suggests some answers. 2Whales are ocean animals. The fin, bowhead, gray, humpback and sperm whales are the largest animals living today. In fact, the blue whale is the largest animal known to have ever existed, bigger than any dinosaur. 3The recent study by researchers in Brazil found that four genes appear to play a big part in whales' huge size, a condition known as gigantism. The researchers said the four genes appear to have produced great size while easing the problems linked with it, such as cancer risk and lower reproductive ability. 4Whales are part of the ocean animal family called Cetaceans, which includes dolphins and porpoises. Scientists think the family developed 50 million years ago from animals like wolves, but is also related to today's cows, pigs, sheep and similar animals. 5Mariana Nery, a genetics expert with the University of Campinas (UNICAMP) in Brazil, was a lead writer of the report. It appeared in the publication Scientific Reports. Nery said her team has done 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." 6The study examined seven kinds of whales that grow longer than 10 meters. Six of them are toothless animals. Instead, they have structures called baleen in their mouths that catch very small animals. The seventh species studied was the sperm whale, which has large teeth to feed on giant squid and ocean animals. 7The whales can reach huge sizes. Humpback and right whales can reach 15 meters in length; the sperm and bowhead whales, 18 meters; the fin whale can reach 24 meters, and the biggest, the blue whale, has been measured at 30 meters. 8The researchers studied several genes linked to increased body size in other animals. They found four genes that appeared to be important in the development of whales. 9One of the genes is GHSR. It is involved in releasing growth hormone from the pituitary gland, a part of the body that releases important chemicals. Growth hormone can cause hunger and it can control metabolism and the growth of fat. The gene also controls cell division. 10A second gene is called IGFBP7. This gene is involved in cell growth and division. There is evidence that this gene acts to suppress cancer in many parts of the body including the prostate, breasts, lungs, colon and rectum. 11NCAPG is a gene associated with growth in humans, horses, cattle, pigs and chickens. It can cause size and weight gain and affects the lives of cells. 12The gene PLAG1 is associated with body growth in cows, pigs and sheep. It is involved in the growth of embryos and cell survival. 13The study also suggests that the genes such as GHSR and IGFBP7, which are linked to huge size, might also control cell development and suppress cancer. Huge size in nature is tied to shorter lifespans. But huge whales live long lives. The humpback whale can reach 50 years of age. The blue whale can reach 90 and, the study noted, the bowhead whale is the longest-lived mammal known, reaching 200 years of age. 14Felipe Andre Silva was lead writer of the study. He worked on the research while earning his master's degree in genetics and molecular biology. 15He said gigantism in whales appeared relatively recently, around 5 million years ago. "Before that there were animals with large sizes...but these were exceptions, and most cetaceans did not exceed 10 meters in length," he said. 16Silva told Reuters news agency: "Gigantism may bring some advantages such as a lower chance of being preyed upon and a greater change of obtaining food." 17Nery 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 remain popular and interesting to many people and gain a lot of attention. Nery added, "The evolution of cetaceans is a fantastic story..." 18I'm Mario Ritter, Jr. And I'm Caty Weaver. 19Mario Ritter, Jr. adapted this report for VOA Learning English from Associated Press and other sources. 20________________________________________________________________ 21Words in This Story 22hormone -v. a substance produced by the body that influences growth, development and how organs work 23metabolism -v. the processes essential for life by which the complex substances in the cells of living things are built up or broken down 24exceed -v. to become greater or bigger than something 25advantage -n. a desirable or good quality 26prey -v. to seize and eat something hunted 27obtain -v. to get or gain something through effort 28fantastic -adj. extremely good, usual or strange 29_______________________________________________________________ 30We want to hear from you. 31We have a new comment system. 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