UNIVERSITY PARK, Pa., Dec. 26 (UPI) -- Human evolution may have been accelerated by rapid climate changes in East Africa around 2 million years ago, U.S. researchers say.
Scientists at Penn State and Rutgers University said their study challenges a long-held belief humans evolved in response to a long, consistent altering of the climate.
"The landscape early humans were inhabiting transitioned rapidly back and forth between a closed woodland and an open grassland about five to six times during a period of 200,000 years," Penn State geoscience graduate student Clayton Magill said.
"These changes happened very abruptly, with each transition occurring over hundreds to just a few thousand years," he said in a Penn State release.
This is in contrast to the current leading hypothesis of a single change in the environment that brought on drier conditions, researchers said.
"There is a view this time in Africa was the 'Great Drying,' when the environment slowly dried out over 3 million years," Penn State geoscience Professor Katherine Freeman said. "But our data show that it was not a grand progression towards dry; the environment was highly variable."
The reaction of early humans to the variations could have triggered cognitive development, Magill said.
"Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response," he said. "Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes. The result can be increased brain size and cognition, changes in locomotion and even social changes -- how you interact with others in a group."
Iran says cyberattack successfully foiled
TEHRAN, Dec. 26 (UPI) -- Iran says it has successfully countered a cyberattack by the Stuxnet computer worm on a power plant and other industries in the south of the country.
Officials are saying the attack was successfully pushed back and prevented from spreading, the BBC reported Wednesday.
"The Bandar Abbas electricity supply company has come under cyberattack," civil defense chief Ali Akbar Akhavanhe in the Hormozgan province said. "But we were able to prevent its expansion owing to our timely measures and the co-operation of skilled hackers."
The Stuxnet worm caused significant damage to Iran's nuclear enrichment activities in 2010 in an attack Tehran blamed on Israel and the United States.
In late 2011 Iran said some of its computer systems were infected by spyware believed to have been intended to gather data to be used in further cyberattacks, and in April this year a cyberattack on Iran's oil ministry and national oil company caused the government to take key oil facilities offline, the BBC reported.
Tigers make comeback in some global areas
NEW YORK, Dec. 26 (UPI) -- Endangered tigers are making a comeback due to better law enforcement, protection of habitat and strong government partnerships, a U.S. wildlife group says.
In three key regions of the big cats' global range -- India, Thailand and Russia -- there have been successes in conserving and protecting the animals, the Wildlife Conservation Society reported Wednesday.
Twenty-five years of research and conservation efforts have resulted in a major rebound of tigers in the Western Ghats region of India's Karnataka State, the WCS said.
In Thailand, an increase in anti-poaching patrols and enforcement has seen a recovery of tiger numbers in the 1,042-square-mile Huai Kha Khaeng Wildlife Sanctuary, WCS officials said.
Russian government officials are drafting a new law to make transport, sales and possession of endangered animals a criminal offense rather than just a civil crime, the group said.
The WCS said it estimates 3,200 tigers exist in the wild, with poaching, loss of prey, and habitat destruction driving tiger numbers at all-time lows.
"Saving tigers is clearly a team effort," John Robinson, WCS executive vice president of conservation and science said. "Today's victories show that through collaboration with governments, law enforcement, fellow conservationists, and local people, we can save these big cats across their range."
Russia ready to sign on to Mars project
MOSCOW, Dec. 26 (UPI) -- Russia's Federal Space Agency says it could sign an agreement in the first quarter of 2012 on participating in a European Mars research project.
Roscosmos General Director Vladimir Popovkin said the agency is ready to sign the long anticipated agreement with the European Space Agency, RIA Novosti reported Wednesday.
"The agreement will be signed," Popovkin said. "We are starting financing this project."
The ExoMars program -- to send an orbiter to Mars in 2016, followed by a robot rover two years later was -- originally a joint project of the ESA and NASA, but NASA cut its participation, citing funding issues, and said it could not provide its Atlas rocket for the launch.
Russia then stepped in and offered to provide its Proton launch rockets and scientific equipment in exchange for full membership in the project.
The signing of the agreement with the European Space Agency had been expected in November but was delayed due to "the complexity of official procedures adopted by ESA," Popovkin said.
"The text of the document will be agreed 'up to a single comma' by January 20," he said.