In a pilot study, scientists have shown that meat and milk from cloned bulls and cows, respectively, meet industry standards.
Xiangzhong Yang and colleagues cloned a Japanese Black beef bull and Holstein dairy cow, using somatic cell nuclear transfer (the same technique used to clone the sheep Dolly). The researchers compared the meat and milk from the clones to that of animals of similar age, genetics, and breed created through natural reproduction.
Analysis of protein, fat, and other variables routinely assessed by the dairy industry revealed no significant differences in the milk. The researchers also examined more than 100 meat quality criteria, of which 90% showed no noteworthy variations. But about 8 variables related to the amount of fat and fatty acids in the meat were significantly higher in the meat from the clones. The authors say these higher fat levels are within beef industry standards.
Animal food products from clones have yet to enter the food chain in any country, and this report lays groundwork for larger, more conclusive studies with cloned animals.
*Humans, Not Climate Change, Likely Cause of Elephant Extinctions
When early humans migrated out of Africa, they hunted elephants to extinction on five continents, archaeological evidence suggests.
A million years ago, elephants lived in most of Africa, Europe, Asia, and the Americas. Today, wild elephants are found only in portions of sub-Saharan Africa and South Asia. Whether these die-offs were due to climate change or human overkill has been a source of debate.
To investigate the question, Todd Surovell and colleagues examined 41 archaeology sites--ranging from 1.8 million years to 10,000 years ago,
on five continents--that showed humans and elephants living together in the same place and time. By comparing age and location of the sites
with early hum
Contact: Leikny Johnson
Proceedings of the National Academy of Sciences (PNAS)