Science Briefs

Ancient hunting trap found in Lake Huron

Underwater archaeologists have discovered evidence of prehistoric caribou hunts that provide unprecedented insight into the social organization of early peoples in the Great Lakes region.

An article detailing the discovery of a 9,000-year-old caribou hunting drive lane under Lake Huron was published in April in Proceedings of the National Academy of Sciences.

University of Michigan anthropologist John O’Shea, lead author of the article, said the site is on a ridge, under 121 feet of water, about 35 miles southeast of Alpena, Mich., on what was once a dry land corridor connecting northeast Michigan to southern Ontario.

The main feature is the most complex hunting structure found to date beneath the Great Lakes. Constructed on level limestone bedrock, it is composed of two parallel lines of stones leading toward a cul-de-sac formed by the natural cobble pavement. Three circular hunting blinds are built into the stone lines; additional stone alignments may have served as blinds and obstructions for corralling caribou.

Chipped stone debris for repairing stone tools provides evidence for intentional human construction and use of the feature, O'Shea said.

Groovy turtle’s genes studied

The diverse patterns on the diamondback terrapin’s intricately grooved shell may be its claim to fame, but a newly published U.S. Geological Survey study of the genetic variation underneath its shell holds one key to rescuing these coastal turtles.

The terrapin is the only turtle in North America that spends its entire life in coastal marshes and mangroves. Subspecies of terrapins are currently recognized by scientists based on external traits, such as their skin color and the shape of their shells. Each subspecies occupies a strip of seaboard from Massachusetts to as far as Texas.

“Diversity loss can be a silent threat to many species,” explained Maggie Hunter, a USGS research geneticist and co-author of the study, published recently in the journal Conservation Genetics. “The threat to long-term survival of terrapins occurs if they become separated into isolated groups. Isolation can affect their overall survival several generations down the line.”

To identify natural genetic variations, USGS studied the turtles’ breeding patterns using DNA from blood samples of nearly a thousand terrapins. Based on their variation in 12 genetic markers, the terrapins were assigned into genetically similar groups. They found only four genetically distinct populations – a surprise, given there are seven recognized terrapin subspecies. This means that “natural breaks” in genes don’t correspond to the ranges of those subspecies.

One benefit of the research: Turtles rescued from poachers can be returned to their original habitat. USGS

Wines’ fruity flavors fade first

Recent research from Washington State University, published in the journal Food Quality and Preference, reveals how different flavors “finish,” or linger, on the palate following a sip of wine.

The study is one of the first to look at how different flavor components finish when standing alone or interacting with other compounds in white wines. Sensory scientist Carolyn Ross’ team trained panelists to identify and measure fruity, floral, mushroom and oaky (or coconut) compounds in wines. They found that fruity flavor perception disappears from the palate earlier than oaky, floral and earth flavors perception.