Genetics

Blue eyes are typically associated with beauty, or perhaps Frank Sinatra. But to University of Wisconsin anthropologist John Hawks, they represent an evolutionary mystery. For nearly all of human history, everyone in the world had brown eyes. Then, between 6,000 and 10,000 years ago, the first blue-eyed baby was born somewhere near the Black Sea.

It looked like an open-and-shut case. More than half the genes in the H1N1 virus behind the current flu outbreaks were traced to pigs. The first person known to be sickened with swine flu in Mexico, the outbreak's epicenter, lived near an industrial farm that produces almost a million hogs a year. The virus was quickly dubbed "swine flu." Officials in Egypt ordered destruction of all 300,000 of the country's pigs. Afghanistan's one known pig was quarantined.

2Amid the tumult of the delivery room, Rohit and Geeta Jain were calm about one thing: Their new baby was sure to be a boy. Six months earlier, the Jains had spent more than $300 for a test that screened a minute quantity of Geeta's blood for traces of male DNA. The testing company said it was 95% accurate in determining the sex of a baby, even as early as the eighth week of pregnancy. After six hours in the delivery room, Rohit gaped as his wife gave birth to a daughter.

The last two years have seen an exponential increase in the rate of gene discovery, thanks in large part to the advancements in so-called genotyping chip technology. These small glass or silicon platforms have made quick and easy work of simultaneously analyzing hundreds of thousands of genetic variations that exist in the human genome. The screens detect single-letter changes in the DNA code known as single nucleotide polymorphisms, or SNPs (pronounced "snips").

When a falcon swoops from the sky to seize its prey, no one would mistake the predator for a gaudy parrot. Yet the secret kinship of falcons and parrots is one of many surprises in a landmark genetic study of 169 bird species published by Field Museum researchers. One likely consequence of the study in Friday's edition of the journal Science is a reordering of the field guides that many of America's 80 million bird-watchers use.

Countering the prevailing theory that aging is the accumulation of wear and tear in cells, scientists studying worms have found that aging may be hard-wired, a sort of unintentional sabotage by genes gone wild. The study, published Thursday in the journal Cell, found that metabolic processes important during development may shift later in life in ways that harm the worms, causing them to age and die.

A genetic analysis of a biopsy sample recently discovered in the Democratic Republic of the Congo has led researchers to conclude that the virus that causes AIDS has existed in human populations for more than a century, according to a study released Wednesday. The study, led by evolutionary biologist Michael Worobey of the University of Arizona in Tucson, puts the date of origin at around 1900, which is 30 years earlier than previous analyses.

Massachusetts scientists have identified a gene linked to the most common type of kidney cancer in children, and expressed hope this might help doctors determine which patients are most at risk of dying. In a report Friday in the journal Science, the team said about 30% of Wilms tumor cases involve mutations in a gene called WTX on the sex-determining X chromosome. About 90% of childhood kidney cancer cases are Wilms tumor, which occurs in one in 10,000 children worldwide.

A one-celled parasite called \o7Trichomonas vaginalis\f7, which causes an itchy and smelly genital infection especially dangerous to women, has nearly as many genes as a human being, researchers reported Friday in the journal Science. The parasite affects at least 170 million people globally. A team of 66 researchers in 10 countries led by Dr. Jane Carlton of the New York University School of Medicine found the protozoan has close to 26,000 genes.

Scientists have identified a gene that increases the risk for late-onset Alzheimer's and provides another clue into the complex mind-robbing disease. The gene -- SORL1 -- stands out because it's been tested in four ethnic groups and a form of it seems to confer a risk in all of them -- including North Europeans, Caribbean Latinos, African Americans and Israeli Arabs.