Beringia on EARTH Magazine

A long layover on the Bering land bridge

Wed, 16 Mar 2016 20:22:15 -0400

The Late Pleistocene remains of two infants recovered from the Upper Sun River campsite in eastern Alaska are shedding light on the peopling of the Americas. Credit: K. Cantner, AGI, after Tackney, et al. 2015.

About 11,500 years ago, two infants were laid to rest side by side in a shallow grave 80 kilometers southeast of what is now Fairbanks, Alaska. The area was once part of Beringia, a strip of ice-free land connected to Asia during the last ice age. Researchers found the remains in 2013, and have now sequenced the complete mitochondrial genomes of the two children. The results revealed that the infants had different mothers and that their genetic signatures are found today throughout North and South America.

Message in a bottle gourd

Mon, 23 Jun 2014 17:47:10 -0400

Bottle gourds hung out to dry. Credit: ©byrev, CC0 1.0.

Logan Kistler of Penn State University and colleagues analyzed DNA from bottle gourds collected at pre-Colombian archaeological sites throughout the Americas, as well as from living wild gourds from all over the world. The pre-Colombian gourds, the researchers reported in Proceedings of the National Academy of Sciences, were closer genetically to African, rather than Asian, gourds, suggesting they traveled from Africa to the New World via a more direct route. Kistler and his colleagues then used ocean drift models to show that ocean currents could plausibly have transported the gourds, and their concealed seeds, across the Atlantic in less than a year. Once the plant arrived and took hold in its new home, large animals could have consumed the wild fruit and helped disperse its seeds across the Americas, the researchers suggested.

Early results

Thu, 05 Jan 2012 06:41:58 -0500

Although our final results won’t begin to be published until early next year, our team met in May to review all the data we had collected so far.

We had drilled several types of cores. Our initial pilot cores, taken in 1998 and 2003, provided proof of concept, demonstrating the importance of these cores as a climate record, as they contain climate data that extend back in time 300,000 years — roughly three times longer back in time than the oldest portions of the Greenland ice core records.

The thrill to drill in the chill

Thu, 05 Jan 2012 06:41:58 -0500

Sunrise at the scientists' field camp on the western shore of Lake El'gygytgyn. El'gygytgyn International Science Crew

One of the tents at the drilling platform. El'gygytgyn International Science Crew

Lake El'gygytgyn as it might have looked during the last peak glaciation 21,000 years ago. El'gygytgyn International Science Crew

Lake El'gygytgyn as it looks today in summer, during the present interglacial. El'gygytgyn International Science Crew

This meteorological station in Chukotka records temperature and precipitation data. El'gygytgyn International Science Crew

The drilling team. El'gygytgyn International Science Crew

Nearly 3.6 million years ago, a large asteroid slammed into Earth in what is today northeastern Russia. Within minutes, the impact formed an 18-kilometer-wide hole in the ground that then filled with water. The sediments that collected in the bottom of that lake since the impact may provide one of the best stratigraphic records of high-latitude climate change over the last 3.6 million years. Last year, we traveled to this remote region to drill into these sediments to see what we could learn about Arctic change.