Axolotl, 'Mexican walking fish,' on threatened-species list
SCIENCE BRIEFING
Researchers say the amphibian, found in the polluted canals of Mexico's Lake Xochimilco, could disappear in five years.
The axolotl, also known as the "water monster" and the "Mexican walking fish," was a key part of Aztec legend and diet but is now threatened with extinction.
Against all odds, it survived until now amid Mexico City's urban sprawl in the polluted canals of Lake Xochimilco, now a Venice-style destination for revelers poled along by Mexican gondoliers.
The International Union for Conservation of Nature includes the axolotl on its annual Red List of threatened species, and researchers say it could disappear in just five years.
Genetics may shed light on lung cancer
An international research team has identified two genetic variations that appear to increase a person's risk of developing lung cancer by up to 60%, they reported Sunday in the journal Nature Genetics.
Smoking is the leading risk factor but increasingly scientists are looking to genetics to help explain why some longtime smokers never develop the disease and why some nonsmokers do.
The study included researchers from 18 countries who analyzed genetic mutations in more than 15,000 people -- 6,000 with lung cancer and 9,000 without the disease.
Return of the woolly mammoth?
The woolly mammoth, extinct for thousands of years, may be closer to a comeback.
A technique that has been used to clone mice and other animals could enable scientists to resurrect long-gone, frozen species such as woolly mammoths, according to a study published Tuesday in the Proceedings of the National Academy of Sciences.
Japanese researchers led by Sayaka Wakayama of the Center for Developmental Biology in Kobe cloned mice using the nuclei of mouse brain cells that had been frozen at minus 4 degrees Fahrenheit for as many as 16 years. Critics, however, say that frozen DNA from the mammoths may be too degraded to regenerate the animals.
Antarctica ozone hole grows
This year's ozone hole over Antarctica, caused by depletion of stratospheric ozone by man-made gases, was the fifth biggest on record, reaching a maximum area of 10.5 million square miles in September, NASA said Wednesday.
That's considered "moderately large," NASA atmospheric scientist Paul Newman said in a statement.
NASA has tracked the size of the hole for 30 years. Last year, it was 9.7 million square miles, about the size of North America.
Brains show pleasure in bullying
