Mammoth hemoglobin offers more clues to Arctic evolution
For the first time in 43,000 years, a woolly mammoth has breathed again on earth.
Well, not the mammoth itself but its hemoglobin, the stuff in red blood cells that takes on oxygen in the lungs and offloads it in the tissues. By reconstructing the mammoth’s hemoglobin, a team led by Kevin L. Campbell of the University of Manitoba in Canada has discovered how the once tropical species adapted to living in arctic temperatures.
“It is a very exciting result and opens a new chapter in paleontology, a subject usually constrained to examining old bones and teeth,” said Adrian Lister, an expert on mammoth evolution at the Natural History Museum in London.
Mammoths, despite their association with the frozen north, originated in the tropics when they split apart from elephants some seven million years ago. To adapt to the cold of northern latitudes they developed smaller ears, a thick fur coat and glands in their skin to keep the fur well oiled.
So much is clear from their remains. But other kinds of adaptation, which have not survived, would also have been necessary. Most arctic animals arrange their blood vessels so that the arteries going down a leg can transfer heat to the veins coming up. The blood reaching the toes is thus quite cold and the animal conserves lots of heat while it stands on frozen ground.
Greece takes its bailout, but doubts for region persist
ATHENS — Greece announced Sunday that it had reached agreement on a long-delayed financial rescue package that would require years of painful belt-tightening, but the deal might not be enough to stop the spread of economic contagion to other European countries with mounting debts and troubled economies.
The bailout, which was worked out over weeks of negotiations with the International Monetary Fund and Greece’s European partners, calls for as much as 120 billion euros, or $160 billion, in loans over the next three years intended to avoid a debt default.
In Greece, Prime Minister George Papandreou, the scion of a Socialist dynasty whose father helped erect the sprawling Greek welfare state when he was prime minister in the 1980s, sought to prepare Greeks for what was expected to be the greatest overhaul of the state in a generation.
“I want to tell Greeks very honestly,” he said, “that we have a big trial ahead of us.”
U.S. farmers cope with Roundup-resistant weeds
Just as the heavy use of antibiotics contributed to the rise of drug-resistant supergerms, American farmers’ near-ubiquitous use of the weedkiller Roundup has led to the rapid growth of tenacious new superweeds.
To fight them, farmers throughout the East, Midwest and South are being forced to spray fields with more toxic herbicides, pull weeds by hand and return to more labor-intensive plowing methods.
Farm experts say that such efforts could lead to higher food prices, lower crop yields, rising farm costs, and more pollution of land and water.
“It is the single largest threat to production agriculture that we have ever seen,” said Andrew Wargo III, the president of the Arkansas Association of Conservation Districts.
The first resistant species to pose a serious threat to agriculture was spotted in a Delaware soybean field in 2000. Since then, the problem has spread, with 10 resistant species in at least 22 states infesting millions of acres, predominantly soybeans, cotton and corn.
The superweeds could temper American agriculture’s enthusiasm for some genetically modified crops. Soybeans, corn and cotton that are engineered to survive spraying with Roundup have become standard in American fields. However, if Roundup does not kill the weeds, farmers have little incentive to spend the extra money for the special seeds.