Where Vikings went, mice followed
YORK, England, March 19 (UPI) -- When Vikings spread across Europe and into the New World, researchers say, they took one unintended "guest" along on their journeys -- the humble house mouse.
In addition to the domestic livestock such as horses, sheep, goats and chickens they took to colonies in Scotland, Ireland, Iceland, Greenland and possibly Newfoundland, they inadvertently took pest species such as mice with them, a study in the journal BMC Evolutionary Biology reported.
Analysis of ancient mouse DNA in modern rodent populations showed the house mice hitched a ride with the Vikings in the early 10th century into Iceland from either Norway or the northern part of the British Isles, and from Iceland continued their journey on Viking ships to settlements in Greenland.
"Human settlement history over the last 1,000 years is reflected in the genetic sequence of mouse mitochondrial DNA," Eleanor Jones from the University of York in Britain said. "We can match the pattern of human populations to that of the house mice."
The researchers said lessons could be gained from both where ancient mouse DNA is found today and where it is not.
"Absence of traces of ancestral DNA in modern mice can be just as important," Jeremy Searle from Cornell University said. "We found no evidence of house mice from the Viking period in Newfoundland.
"If mice did arrive in Newfoundland, then like the Vikings, their presence was fleeting and we found no genetic evidence of it."
'Free' phone apps come with energy cost
WEST LAFAYETTE, Ind., March 19 (UPI) -- Smartphone users wondering why their device's battery life is so short should look at their free apps that U.S. researchers say are energy hogs.
Computer scientists at Purdue University found up to 75 percent of the energy used by free versions of Android apps is spent serving up ads or tracking and uploading user data, NewScientist.com reported Sunday.
When they developed software to analyze the energy usage of smartphone apps, researchers found only 10 to 30 percent of the energy use of popular apps such as Angry Birds, Free Chess and NYTimes went to powering the app's core function.
In Angry Birds, for example, only 20 percent is used to display and run the game, while 45 percent is consumed finding and uploading the user's location using Global Positioning System coordinates so location-appropriate ads can be downloaded over the phone, the researchers said.
That connection remains open for 10 seconds even after the data transmission has been complete, consuming another 28 percent of the app's energy, they said.
Running just one such energy-hungry free app can drain a smartphone battery in around 90 minutes, the researchers said, mostly due to inefficiencies in the third-party code that developers use to generate profit from ads in "free" apps.
Satellite images become archaeology tool
CAMBRIDGE, Mass., March 19 (UPI) -- A U.S. researcher says he's improved the process of using computers to examine satellite images for the telltale signs of early human settlements.
Harvard archaeologist Jason Ur and his colleagues developed a system to identify human habitation from factors such as soil discolorations and the distinctive mounding that results from the collapse of mud-brick settlements. They have used it to uncover thousands of new sites that could be from the earliest complex human societies, a university statement released Monday said.
Ur used a computer to examine satellite images of an 8,800-square-mile area of northeastern Syria and said he's identified about 9,000 possible settlements.
"I could do this on the ground," Ur said about the results of the computer-aided survey. "But it would probably take me the rest of my life to survey an area this size.
"With these computer science techniques, however, we can immediately come up with an enormous map which is methodologically very interesting, but which also shows the staggering amount of human occupation over the last 7,000 or 8,000 years.
"What's more, anyone who comes back to this area for any future survey would already know where to go. There's no need to do this sort of initial reconnaissance to find sites. This allows you to do targeted work, so it maximizes the time we have on the ground."
To create the system described in the Proceedings of the National Academy of Sciences, Ur worked with the Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology.
Spring equinox brings folk beliefs
LOS ANGELES, March 19 (UPI) -- A lot of people Tuesday will try to stand a raw egg on end, believing it's easier on the spring equinox than on any other day -- but it's not, scientists say.
Long-held folk beliefs suggest the position of the sun and other planets on the vernal equinox -- when the sun is positioned directly over the equator -- means miraculous feats of balance can occur.
However, astronomers are adamant that equinoxes and planetary alignments have no "physical effect on earthly objects," About.com says.
Standing eggs on end or balancing a broom on its bristles isn't easy, but it's no more nor less easy on any one day than another.
The Chinese may have originated the egg-standing practice at the spring equinox, as eggs suggest the fertility theme of the vernal equinox, while balancing brooms is popular at the autumnal equinox with its fall atmosphere of witches and Halloween, the Los Angeles Times said.
Some other traditional events are tied to the equinox: Easter always falls on the first Sunday after the first full moon after the vernal equinox.
Nowruz, known widely as the Persian New Year, takes place on the vernal equinox.
And at sunrise on the spring equinox, Egypt's sphinx points directly to the rising sun.
No eggs involved, of course.
