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A bunny a bird and a duck.
MASKED SHREW SIZE - Lathrop High School Senior Kelly May is headed to the National Junior Science & Humanities Symposium in Ohio this month with a research project refuting an earlier study on the effects of climate change on Alaska’s shrews. For this year’s Alaska Statewide High School Science Symposium (ASHSSS), May repeated a study published in 2005 using masked shrew specimens housed at the University of Alaska Museum of the North.
The original study, which concluded that shrews in Alaska are getting larger, was based entirely on data downloaded from the museum’s online database. The authors were not able to inspect each specimen. May believed that not accounting for age in the original research may have biased the results, so he tracked down each of the 650 specimens used in the original study.
Each shrew species has a unique tooth pattern. Since Alaska’s shrews can be difficult to identify, May first confirmed the specimens were the correct species (Sorex cinereus). Determining the age involved looking at the degree of wear on their teeth. Shrews do not hibernate and are active year round but they rarely live more than 15 months. Adults that survive a winter show significant tooth wear, while shrews born in the spring do not.
May learned that young shrews are significantly smaller than overwintered adults and that overwintered females are bigger than overwintered males. In contrast to previously published claims, this means that age and sex both need to be accounted for in studies of body size in shrews, according to the museum’s curator of mammals, Link Olson.
By analyzing juvenile and adult specimens separately and accounting for sex, May found that individual shrews are actually getting smaller but that more are surviving the winter, meaning that the proportion of (larger-bodied) adults in a given population is increasing. So although the two studies reached seemingly similar conclusions, May’s results shed new light on the underlying mechanism: shrews aren’t growing to a larger body size, they’re just surviving winters better.
In June, May will travel to Philadelphia to present his research at the annual meeting of the American Society of Mammalogists. May plans to attend UAF in the fall.
Ctenophores. ‘Cause sometimes evolution only feels like making the mouth.
Today in Lab History: DNA Structure
In 1953, James Watson and Francis Crick submitted to the journal Nature their first article on the structure of DNA. It was published in the 25 Apr 1953 issue.
Read more: http://www.laboratoryequipment.com/news/2012/09/today-lab-history
A Year in the Life of the Bowhead Whale
a film by the UA Museum of the NorthOur whale heroes may be 15 meters large, but their prey can be as small as a grain of rice. This week, we took one of our previously built open underwater environments and made a host of changes, including swimming inch-long krill models with better textures, some new experiments with underwater “fog” and camera rack-focus and motion blur, and topped it off with a statistical spectrum wave simulation which gives results that are about as real as it gets for simulated sea surface wind-driven waves.
UAMN Head of Production Roger Topp
Retro muskox
Bones
Musk ox at -40
(Source: facebook.com)
