News Articles

Questions about human migration from Asia to the Americas have perplexed anthropologists for decades, but as scenarios about the peopling of the New World come and go, the big questions have remained. Do the ancestors of Native Americans derive from only a small number of “founders” who trekked to the Americas via the Bering land bridge? How did their migration to the New World proceed?
A team of 21 researchers, led by Ripan Malhi, a geneticist in the department of anthropology at the University of Illinois, has a new set of ideas.

A team of scientists led by a researcher at the University of Alaska Fairbanks has identified a new likely source of a spike in atmospheric methane coming out of the North during the end of the last ice age.
Methane bubbling from arctic lakes could have been responsible for up to 87 percent of that methane spike, said UAF researcher Katey Walter, lead author of a report printed in the Oct. 26 issue of Science magazine. The findings could help scientists understand how current warming might affect atmospheric levels of methane, a gas that is thought to contribute to climate change.
“It tells us that this isn’t just something that is ongoing now. It would have been a positive feedback to climate warming then, as it is today,” said Walter.

Ancient DNA retrieved from the bones of two Neanderthals suggests that at least some of them had red hair and pale skin, scientists report this week in the journal Science.

Halloween is a time for children to dress up as witches, ghouls and goblins, but historically witchcraft was serious business, according to a Duke University professor.
Though people today might view witchcraft as mere superstition, it’s evident from anthropological literature that, for some people, the practice has served a basic human need, said Anne-Maria Makhulu, an assistant professor of cultural anthropology who studies the ongoing practice of witchcraft in Africa.
"We live in a bewildering world where we don’t have a lot of control. And we can imagine doing things through magic that we can’t do as ordinary human beings," said Makhulu, who is teaching a course this semester on magic(!) and capitalism(!!).

University of Utah biologists genetically manipulated nematode worms so the animals were attracted to worms of the same sex – part of a study that shows sexual orientation is wired in the creatures’ brains.
“They look like girls, but act and think like boys,” says Jamie White, a postdoctoral researcher and first author of the new study. “The [same-sex attraction] behavior is part of the nervous system.”
The study was published Thursday, Oct.

Nearly a third of the world’s 6,000 amphibian species are threatened with extinction and more than 120 species have already vanished from the planet.
Across the globe, conservation organisations and professionals are mobilising efforts to help save as many of these species as possible.
A brightly coloured tropical frog under threat of extinction is the focus of a new research project hoping to better understand how environment and diet influence its development and behavior.

Credit: University of Manchester

The shortage of islet cells limits the development of islet transplantation. One new approach was reported in the October 21 issue of the World Journal of Gastroenterology because of its great significance in enhancing the output of islet cells.
The article describes the differentiation of rat pancreatic ductal epithelial cells into insulin-producing cells by the transfection of PDX-1. In recent years, though great efforts have been made to differentiate embryonic stem cells, pancreatic ductal epithelial multipotent progenitor cells and bone marrow stem cells into islet cells, the process of cell differentiation and growth is long. Moreover, the amount of islet cells of differentiation, and the insulin released by islets, is not enough to meet the clinical needs.

The greatest mass extinction in Earth’s history also may have been one of the slowest, according to a study that casts further doubt on the extinction-by-meteor theory.
Creeping environmental stress fueled by volcanic eruptions and global warming was the likely cause of the Great Dying 250 million years ago, said USC doctoral student Catherine Powers.
Writing in the November issue of the journal Geology, Powers and her adviser David Bottjer, professor of earth sciences at USC, describe a slow decline in the diversity of some common marine organisms.

More than 250 million women worldwide smoke tobacco. Compared to men, women have a greater risk of smoking-related diseases, and also have more difficulty quitting. A new study, the first of its kind, has found that cigarette smoking and having a family history of alcoholism have different effects on sweet-taste perception and food cravings.
“Tobacco is one of the most heavily used addictive drugs,” said M. Yanina Pepino, a researcher at the Monell Chemical Senses Center in Philadelphia and corresponding author for the study, “leading to an increased risk of lung and heart diseases and a variety of cancers.” In fact, lung cancer has surpassed breast cancer as the leading cause of death among US women, she added.

Severely restricting calories leads to a longer life, according to research in the October issue of Journals of Gerontology Series A: Biological Sciences and Medical Sciences.
The study says such a diet can also maintain physical fitness into advanced age, slowing the seemingly inevitable progression to physical disability and loss of independence.
Using a rat model of life-time caloric restriction, they showed that the diet reduces the amount of visceral fat, which expresses inflammatory factors that in humans cause chronic disease and a decline in physical performance and vitality across the lifespan.

Thousands of high school students are currently deliberating over which university to attend next year. But which are the best? A study published in the open access journal BMC Medicine warns against using international rankings of universities to answer this question. They are misleading and should be abandoned, the study concludes.
The study focuses on the published 2006 rankings of the Times Higher Education Supplement "World University Rankings" and the Shanghai Jiao Tong University "Academic Ranking of World Universities".

A topic often left out of discussions about the promise of personalized medicine that science and society offers for the future is whether or not ordinary people want that extra responsibility. Does everyone want to know if they are susceptible to certain diseases?
A two-day showcase called Genomics and Society: Today’s Answers, Tomorrow’s Questions – is taking place in London on Thursday 25 and Friday 26 October 2007. This gathering brings together policymakers, researchers and natural scientists with what is becoming the world’s largest concentration of social scientific research in this field - the ESRC Genomics Network (EGN).