A massive new genetic study proposes that humans originated near the border of modern-day South Africa and Namibia, a far more specific  understanding than the vaguer picture of African origin that previously reigned.

Researchers from 11 countries collaborated on the study of more than 4 million genotypes, which was published today online in Science. By analyzing genetic sequences from 121 populations in Africa, 60 non-African populations and four African-American populations, they were able to trace Africans back to 14 ancestral clusters.

Charles Darwin first proposed an African origin of humans in his 1871 book The Descent of Man. It's now widely accepted that modern humans spent half of their 200,000 years on the planet in Africa, making it a key area of interest for geneticists, linguists and anthropologists alike.

NEW YORK — The African continent may not be the first place people think of when technology is involved, but many of the countries there have come to depend on mobile phones as their primary means of communication (even more so than landline telephones or computers), and this dependence will only grow in the near future. This reliance on handheld gadgets may come at a cost though, given that they generally have poor cyber security in place, says Seymour Goodman, a Georgia Institute of Technology international affairs and computing professor and co-director of the school's Information Security Center.

Cell phones have flourished in Africa because many of the countries there have few landlines, and computers are still expensive, Goodman said at a Marconi Society symposium here yesterday. He noted that about 300 million of the world's nearly 3.5 billion cell phones are in Africa (which has a population of roughly one billion). "The people of Africa will appreciate that a $300 iPhone will do a lot more for their family than a $100 laptop," he added.

As if biodiversity wasn’t under siege already from encroaching human populations and climate change, it is literally under attack, according to a new study showing that most of the last half-century's conflicts were in the most ecologically rich—and threatened—parts of the planet.

One hundred eighteen of 146 of the wars fought between 1950 and 2000 occurred in biodiversity hot spots, according to the study in Conservation Biology. There are 34 of those hot spots—defined as areas with at least half of all known plant species and at least 42 percent of terrestrial vertebrates—on the globe, based on criteria established in 1988 to prioritize conservation goals.

Staggering numbers of Zimbabweans are at risk of cholera, following the deaths of 775 people and infections among more than 16,000 since August, World Health Organization officials report. Half of the country’s 12 million people could be exposed to the disease, which is spread through contaminated food or water and poor sanitation, and an estimated 60,000 are believed to be at risk of contracting it.

The outbreak reflects a stark decline in health in Zimbabwe since last year, when there were just 65 cases of cholera and four deaths, according to WHO statistics. Basic government services in the country, including the provision of water and garbage collection, have collapsed under President Robert Mugabe, who insisted yesterday that the epidemic is over, today’s New York Times notes. The disease has spilled into neighboring South Africa, where 460 cases and nine deaths have been reported.

Among the unresolved issues surrounding the AIDS pandemic is which strategy — pushing prevention techniques or HIV treatments — will best reduce the disease's spread. Now, World Health Organization (WHO) researchers say that annual testing and immediate drug treatment of those who test positive for HIV, the virus that causes AIDS, could within a decade virtually eliminate new cases of AIDS in the hardest-hit countries.

The findings, published this week in The Lancet, are based on a mathematical model. They don't reflect a change in WHO's current recommendation of voluntary testing, the agency says. "This is a theoretical exercise based on mathematical modeling to stimulate discussion," Kevin de Cock, head of WHO's AIDS department, told the Washington Post.

Although acquired immune deficiency syndrome (AIDS) didn't hit mainstream collective consciousness until the early 1980s, new research out of the University of Arizona in Tucson indicates that the most pervasive global strain of human immunodeficiency virus (HIV) began spreading among humans between 1884 and 1924, a finding that suggests growing urbanization in colonial Africa set the stage for the HIV/AIDS pandemic.

Michael Worobey, an assistant ecology and evolutionary biology professor at Arizona, led the research, which studied a number of HIV-1 (the strain found in most cases outside of Africa) genetic sequences to determine the time periods when the virus genetically diverged from its predecessors. These findings, published in the current issue of Nature, were mapped out in the form of a family tree whose roots date back to the beginning of the 20th century.