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Sanctity of Truth
THE NEW YORK TIMES INTERNATIONAL WEEKLY
MONDAY, JUNE 15, 2015
SCIENCE & TECHNOLOGY
A Mystery Disease Kills Saigas on the Steppes By CARL ZIMMER
Before the end of the last Ice Age, saigas roamed by the millions from England to Siberia. Eventually they moved to the steppes of Central Asia, where they continued to thrive — until the 20th century, when these strange-looking antelopes began flirting with extinction. Hunted for its horns, 95 percent of the population disappeared, and the saiga was declared critically endangered. After strict antipoaching measures were imposed, the population recovered, from a low of 50,000 to about 250,000 last year. “It was a big success story,” said Eleanor J. Milner-Gulland, the chairwoman of the Saiga Conservation Alliance. Now that success is in jeopardy. In May, a mysterious disease swept through the remaining saiga herds, littering the steppes with carcasses. The die-off
A disease with ‘100 percent mortality’ astonishes scientists. claimed more than half of the world’s population in just weeks. “To lose 120,000 animals in two or three weeks is a phenomenal thing,” said Joel Berger, a senior scientist at the Wildlife Conservation Society. An international team of wildlife biologists is examining tissues from dead saigas, hoping to figure out what killed them. In the spring, saigas migrate across the steppes by the thousands, the females pausing just long enough to give birth, usually to twin calves. Saigas can travel more than 80 kilometers a day, and can run about 60 kilometers per hour. Naturalists are quick to note their enormous noses somewhat resembling like elephant trunks. “In the rutting season, the male’s nose swells even more, and then they shake their heads and it makes a squishy sound,”
said Aline Kühl-Stenzel, the terrestrial species coordinator of the Convention on the Conservation of Migratory Species of Wild Animals. Females may be attracted to the fleshy noses of males. But scientists also suspect the noses protect saigas from dust rising up from the dry ground. “To some extent, the nose is a filter,” she said. “But it probably also cools the air in the summer, and in winter, it probably heats the air, as well.” From time to time, saigas have faced die-offs. In 2010, 12,000 animals died. The causes are still uncertain. On May 13, Dr. Kühl-Stenzel started receiving reports from government officials in Kazakhstan that another die-off was beginning. The die-off is now 10 times bigger than the 2010 event. And because the saiga population was at a precariously low level, the die-off has claimed an astronomical proportion of the species, from one-third to perhaps a half. Richard A. Kock, an expert on wildlife disease at the Royal Veterinary College in London, was astonished by the deadliness of the disease. Once it struck a herd, every animal died. “It is an extraordinary thing to get 100 percent mortality,” Dr. Kock said. He and his colleagues found that the saigas were infected with two species of deadly bacteria, Pasteurella and Clostridium. But Dr. Kock says he suspects that the infections became deadly only after something else had crippled the animals. So what is killing the saigas? One possibility is that an unknown virus has swept through the herds. Changes in the environment also may have contributed. This year’s heavy rainfalls may have led to a growth of plant species that make saigas dangerously bloated, for example. Central Asia has also had heavy chemical pollution over the decades from factories and farms. “We have to do the science and let the evidence speak,” Dr. Kock said.
REUTERS
In May, more than 100,000 saigas died in Central Asia. Scientists are studying dead animal’s tissue to find the cause.
JOHN SEATON CALLAHAN/GETTY IMAGEHS
Crossbreeding rice resistant to flooding helped improve crop yields in Southeast Asia.
Shifting Strategy Over G.M.O.s By GINA KOLATA
What’s in a name? A lot, if the name is genetically modified organism, or G.M.O., which many people are vehemently against. But what if scientists used the precise techniques of today’s molecular biology to give back to plants genes that had long ago been bred out of them? And what if that process were called “rewilding?” A group at the University of Copenhagen is proposing the name for the process that would result if scientists took a gene or two from an ancient plant variety and melded it with more modern species to promote greater resistance to drought, for example. “I consider this something worth discussing,” said Michael B. Palmgren, a plant biologist at the Danish university who headed a group, including scientists, ethicists and lawyers, that is funded by the university and the Danish National Research Foundation. They published their proposal recently in the journal Trends in Plant Science. The best way to improve plants, they say, is with “precision breeding,” using wellknown modern methods for inserting and deleting genes in cells. The researchers wrote that in the United States and Canada, non-G.M.O. foods are prohibited from having genes that could not have occurred in nature in that plant. So adding a fish gene to a plant, for example, is forbidden, but adding a gene from an ancient variety of the same plant using precision breeding would be allowed. In Europe, however, the methods of genetic engineering are actually banned, even if the gene that is added is from the same plant. That means “rewilded” foods created with precision breeding could be labeled non-G.M.O. in the United States, but not in Europe, they conclude. Brise Tencer, executive director of the Organic Farming Research Foundation in
JOSH HANER FOR THE NEW YORK TIMES
Santa Cruz, California, said she doubts that proponents of G.M.O.-free foods would accept precision breeding. “They take a term that sounds really wonderful, but genetic engineering is genetic engineering is genetic engineering,” Ms. Tencer said. “It is not something farmers want. It is not something consumers want. I don’t think it is a very viable concept.” The idea of restoring longlost genes to plants is not new, said Julian I. Schroeder, a plant researcher at the University of California, Davis. But, wary of
Ancient plant genes are mixed with modern species. the taint of genetic engineering, scientists have used traditional methods to cross modern plants with ancient ones until they have the gene they want in a crop plant that needs it. The tedious process inevitably drags other genes along with the one that is targeted. But the older process is “natural,” Dr. Schroeder said. For example, in 2006, scientists discovered an ancient variety of rice that produces meager yields but resists flooding. Scientists found the gene that makes the rice resistant to flooding; after a couple of years of crossbreeding, researchers were able to grow rice plants
Researchers say precision breeding could help plants thrive in poor conditions. Wheat outside Ciudad Obregon, Mexico.
with the flood resistance gene of the ancient rice. Now, Dr. Schroeder says, flood-resistant rice is grown by more than four million farmers in Southeast Asia. Many of the plants grown today by both conventional and organic farmers were created with imprecise methods, scientists said. Researchers deliberately mutated plants with chemicals and radiation, altering thousands of genes at once, and then searched the resulting plants to find ones with traits they wanted. Though the plants were created using unnatural methods, they can be grown using organic farming techniques. Nina Fedoroff, a plant researcher at Pennsylvania State University, said it seems nonsensical to say a plant is natural when it is mutated by chemicals and radiation, but not when a gene from an ancient variety of the same plant is added with methods of molecular biology. With the flood-resistant rice plants, researchers crossbred and did not use precision breeding to alter the plants. Asked why not, Dr. Schroeder had a simple answer — a complex maze of regulations governing genetically engineered crops. With crossbreeding, he said, “the first varieties hit the fields in a couple of years.” And if the researchers had used precision breeding to get the gene into the rice? “They would still be stuck in the regulatory process,” Dr. Schroeder said.