Wednesday, May 27, 2009

Opposites attract — how genetics influences humans to choose their mates

Opposites attract — how genetics influences humans to choose their mates

attractVienna, Austria: New light has been thrown on how humans choose their partners, a scientist will tell the annual conference of the European Society of Human Genetics today (Monday May 25). Professor Maria da Gra├ža Bicalho, head of the Immunogenetics and Histocompatibility Laboratory at the University of Parana, Brazil, says that her research had shown that people with diverse major histocompatibility complexes (MHCs) were more likely to choose each other as mates than those whose MHCs were similar, and that this was likely to be an evolutionary strategy to ensure healthy reproduction.

Females’ preference for MHC dissimilar mates has been shown in many vertebrate species, including humans, and it is also known that MHC influences mating selection by preferences for particular body odours. The Brazilian team has been working in this field since 1998, and decided to investigate mate selection in the Brazilian population, while trying to uncover the biological significance of MHC diversity.

The scientists studied MHC data from 90 married couples, and compared them with 152 randomly-generated control couples. They counted the number of MHC dissimilarities among those who were real couples, and compared them with those in the randomly-generated ‘virtual couples’. “If MHC genes did not influence mate selection”, says Professor Bicalho, “we would have expected to see similar results from both sets of couples. But we found that the real partners had significantly more MHC dissimilarities than we could have expected to find simply by chance.”

Within MHC-dissimilar couples the partners will be genetically different, and such a pattern of mate choice decreases the danger of endogamy (mating among relatives) and increases the genetic variability of offspring. Genetic variability is known to be an advantage for offspring, and the MHC effect could be an evolutionary strategy underlying incest avoidance in humans and also improving the efficiency of the immune system, the scientists say.

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The MHC is a large genetic region situated on chromosome 6, and found in most vertebrates. It plays an important role in the immune system and also in reproductive success. Apart from being a large region, it is also an extraordinarily diverse one.

“Although it may be tempting to think that humans choose their partners because of their similarities”, says Professor Bicalho, “our research has shown clearly that it is differences that make for successful reproduction, and that the subconscious drive to have healthy children is important when choosing a mate.”

The scientists believe that their findings will help understanding of conception, fertility, and gestational failures. Research has already shown that couples with similar MHC genes had longer intervals between births, which could imply early, unperceived miscarriages. “We intend to follow up this work by looking at social and cultural influences as well as biological ones in mate choice, and relating these to the genetic diversity of the extended MHC region”, says Professor Bicalho.

“We expect to find that cultural aspects play an important role in mate choice, and certainly do not subscribe to the theory that if a person bears a particular genetic variant it will determine his or her behaviour. But we also think that the unconscious evolutionary aspect of partner choice should not be overlooked. We believe our research shows that this has an important role to play in ensuring healthy reproduction, by helping to ensure that children are born with a strong immune system better able to cope with infection.”

Friday, May 15, 2009

Diamonds pile up worldwide as consumers finally realize their worthlessness.

Diamonds pile up worldwide as consumers finally realize their worthlessness.


By ANDREW E. KRAMER May 11, 2009


Each day, the contents of the bags spill into the stainless steel hoppers of the receiving room. The diamonds are washed and sorted by size, clarity, shape and quality; then, rather than being sent to be sold around the world, they are wrapped in paper and whisked away to a vault — about three million carats worth of gems every month.

“Each one of them is so unusual,” said Irina V. Tkachuk, one of the few hundred people, mostly women, employed to sort the diamonds, who sees thousands of them every day.

“I’m not a robot. I sometimes think to myself ‘wow, what a pretty diamond. I would like that one.’ They are all so beautiful.”

It could be years before another woman admires that stone. Russia quietly passed a milestone this year: surpassing De Beers as the world’s largest diamond producer. But the global market for diamonds is so dismal that the Alrosa diamond company, 90 percent owned by the Russian government, has not sold a rough stone on the open market since December, and has stockpiled them instead.

As a result, Russia has become the arbiter of global diamond prices. Its decisions on production and sales will determine the value of diamonds on rings and in jewelry stores for years to come, in one of the most surprising consequences of this recession.

Largely because of the jewelry bear market, De Beers’s fortunes have sunk. Short of cash, the company had to raise $800 million from stockholders in just the last six months.

The recession also coincided with a settlement with European Union antitrust authorities that ended a longtime De Beers policy of stockpiling diamonds, in cooperation with Alrosa, to keep prices up.

Though it is a major commodity producer, Russia has traditionally not embraced policies that artificially keep prices up. In oil, for example, Russia benefits from the oil cartel’s cuts in production, but does not participate in them.

Diamonds are an exception. “If you don’t support the price,” Andrei V. Polyakov, a spokesman for Alrosa, said, “a diamond becomes a mere piece of carbon.”

In an attempt to carefully calibrate its re-entry on the global market, without forcing prices still lower, Russia is relying on two things: the Soviet-era precious gem depository — created to hold jewelry confiscated from the aristocracy after the 1917 revolution — and capitalist investors, whom Alrosa hopes will buy diamonds as an investment, like gold.

Russia is taking a leadership role in other ways, too.


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Sergei Vybornov, Alrosa’s chief executive, said that he had helped persuade the central bank of Angola — which, like Russia, is still relatively flush with oil money — to buy 30 percent of the production of Angola’s diamond mines, keeping these stones off the market.

And last fall, Alrosa began what it called the St. Petersburg Initiative, along with De Beers and other large producers, to invest collectively in generic diamond advertising, akin to De Beers’s promotion of the slogan “Diamonds are forever.” Russia assumed the task as De Beers has principally shifted to promoting its own branded gems.

Still, it is a precarious time for the Russian diamond company to assume leadership of the industry.

Until last year, De Beers produced about 40 percent of the global rough stone supply, and Alrosa 25 percent. But De Beers, which is prohibited under its European Union antitrust agreement from stockpiling, closed mines in response to the glut in rough stones. Russia is loath to do that, as authorities in Moscow, gravely concerned about potential unrest by disgruntled unemployed workers, try to keep workers on the payroll.

In the first quarter, De Beers reduced output by 91 percent compared with the previous year. The diversified mining companies Rio Tinto and BHP Billiton also curbed production.

Meanwhile, the market for wholesale polished diamonds, worth about $21.5 billion, is expected to fall to about $12 billion in 2009, according to Polished Prices, an analytical service for the industry.

Rough diamond prices have fallen even more, as much as 75 percent since their peak last July at some auctions.


The two markets are distinct. Typically, about 60 percent of a rough diamond is lost as dust or shavings in the cutting process.

Mr. Vybornov blames diamond traders who pledged diamond stocks as loan collateral for part of the world glut. When credit dried up last fall, banks and other creditors seized those gems and sold them, he says, flooding the market. By December, his company decided to withdraw entirely from the market rather than further erode prices.

Russia historically remained mostly a behind-the-scenes player, perhaps because Soviet authorities would have had to perform some ideological gymnastics to promote a product consumed principally by the rich of the capitalist world.

Instead, twisting politics, the Soviets concluded a semisecret agreement with apartheid-era De Beers to sell Siberian diamonds in a way that would not undercut the market.

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After the collapse of the Soviet Union, the Russian diamond industry created a formal alliance with De Beers, selling the South African company half of each year’s production at a discount intended to subsidize De Beers’s generic diamond advertising undertaken in the 1990s, mostly in the United States.

Now, the Russians are in the driver’s seat.

Charles Wyndham, a former De Beers evaluator and co-founder of Polished Prices, said Russia had thus far managed the transition well: withholding gems to make more money in the long run rather than further depressing the market.

“Whatever one wants to say about the Russians, they certainly aren’t stupid,” Mr. Wyndham said.

Alrosa is seeking to jump-start demand by selling gems under long-term contracts to wholesale buyers in Belgium, Israel, India and elsewhere. Under these contracts, six of which have been signed, prices are set at a midpoint between the peak last August and this winter, and fixed for a period of several years.

“A diamond ring should not cost $100,” Mr. Vybornov said. “We don’t want that type of client.”

Alrosa is also working with a Moscow investment bank, Leader, a subsidiary of the Russian natural gas monopoly Gazprom, to market diamonds to investors. Under the plan, investors would buy diamonds but the gems would not be released to jewelers for several years.

It is a program, essentially, of outsourcing the stockpiling function to investors in exchange for the chance to profit from a possible recovery in the market.

At one of Alrosa’s cutting shops in one of Moscow’s outer districts, Aleksandr A. Malinin, an adviser to the president of Alrosa, showed a typical collection that might become the basis for such an investment vehicle.

The gems fit in a felt box about the size of a laptop computer.

The larger stones, a circular-cut 10 carat flawless white and a princess-cut yellow, were estimated at about $400,000. The smaller ones ranged from $16,000 to $100,000. But the value of the box, while surely several million dollars, is something of a mystery just now given the depressed market.

How the buy-in price for the stones will be set, and how the company will determine when the price goes up and down, is unclear, Mr. Malinin said.

“We have to tell people that diamonds are valuable,” he said. “We are trying to maintain the price, just as De Beers did, as all diamond producing countries do. But what we are doing is selling an illusion,” meaning a product with no utility and a price that depends on the continued sense of scarcity where there is none.

At the Alrosa unit that receives diamonds, called the United Selling Organization, where about 90 percent of the output of the Siberian mines arrives for processing, Elena V. Kapustkina pours about 45,000 carats of diamonds though a stainless steel sieve every day to sort them by size.

“It’s just a job,” she said.

When asked whether diamonds had lost their romance for her, Ms. Kapustkina paused, looked down at the pile of gems on her table and blushed.

In fact, she said, her husband, a truck driver, gave her a half-carat ring 22 years ago. “Of course I love it,” she said. “It’s from my husband.”

Thursday, May 07, 2009

Nearly one in three US homeowners owe more on mortgage than their home is worth


The downturn in home prices has left about 20% of U.S. homeowners owing more on a mortgage than their homes are worth, according to one new study, signaling additional challenges to the Obama administration’s efforts to stabilize the housing market.

The increase in the number of such “underwater” borrowers comes amid signs that falling prices are making homes more affordable for first-time buyers and others who have been shut out of the housing market. But falling prices also make it more difficult for homeowners who get into financial trouble to refinance or sell their homes, and for others to take advantage of lower interest rates.

For instance, fewer will qualify to take advantage of a key component of the Obama administration’s plan to stabilize the housing market. Under the plan, announced in February, as many as five million homeowners whose loans are owned or guaranteed by government-controlled mortgage giants Fannie Mae and Freddie Mac can refinance their mortgages, but only if the mortgage loan is a maximum of 105% of the home’s value.

Government officials are considering an increase in that limit. “It’s a question that we’re looking at,” said James Lockhart, director of the Federal Housing Finance Agency, which regulates Fannie and Freddie.

Real-estate Web site said that overall, the number of borrowers who are underwater climbed to 20.4 million at the end of the first quarter from 16.3 million at the end of the fourth quarter. The latest figure represents 21.9% of all homeowners, according to Zillow, up from 17.6% in the fourth quarter and 14.3% in the third quarter.

“What’s going on here is that you don’t have any markets that have turned around and you have new markets, like Dallas, that have joined the ranks” of communities where home prices have fallen, said Stan Humphries, a vice president.

Borrowers who owe far more than their home is worth may also be less likely to participate in another part of the government’s housing plan, which provides incentives for mortgage companies to modify loans to make payments more affordable. Thomas Lawler, an independent housing economist, said borrowers who owe 30% more than their homes are worth are far more likely to walk away from their property than those who owe just 5% or 10% more and expect prices to rebound. More than one in 10 borrowers with a mortgage owed 110% or more of their home’s value at the end of last year, according to First American CoreLogic.

There are some recent indications that the housing market could be beginning to stabilize. The National Association of Realtors pending home-sales index, for instance, increased 3.2% in March.

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Just how many borrowers are underwater is a matter of some dispute, with the answer depending in part on assumptions regarding home values and mortgage debt outstanding. Variations in home-price estimates can make a major difference in the number of borrowers who are underwater. In addition, borrowers who are already in the foreclosure process may be counted as being underwater if the title to their property hasn’t changed hands.

Kenneth Rosen, chairman of the Fisher Center for Real Estate and Urban Economics at the University of California, Berkeley, said underwater estimates can be too high if they use price data that includes a large number of foreclosures. Foreclosed homes tend to sell at a discount, he said, making it appear that prices have fallen more than they actually have.

Moody’s estimates that of 78.2 million owner-occupied single-family homes, 14.8 million borrowers, or 19%, owed more than their homes were worth at the end of the first quarter, up from 13.6 million at the end of last year.

Part of the reason Zillow’s numbers are higher may be that it looks at mortgage debt taken out at the time the home was purchased and doesn’t adjust for any payments since made toward the outstanding mortgage balance. It also assumes that borrowers who took out home-equity lines of credit at the time of purchase have fully tapped the amount they can borrow. That approach can overstate the portion of borrowers who are underwater, Mr. Zandi said.

Mr. Humphries of Zillow calls his methodology conservative and said Zillow’s use of pricing for individual homes provides a better measure of home valuations than Mr. Zandi’s approach, which relies on market-level estimates of home values. He adds that Zillow doesn’t include foreclosures in its pricing models.

Write to Ruth Simon at and James R. Hagerty at