(Press-News.org) MANHATTAN, Kan. -- A recent study in the journal Nature finds that nearly 50,000 years ago during the ice age, the landscape was not as drab as once thought -- it was filled with colorful wildflowers. These wildflowers helped sustain woolly mammoths and other giant grazing animals.
The study, "Fifty thousand years of Arctic vegetation and megafauna diet," included Joseph Craine, assistant professor in the Division of Biology at Kansas State University. It was led by the Centre for GeoGenetics at the University of Copenhagen and was a collaboration of more than 25 academic institutions and research laboratories from around the world.
The study looked at 50,000 years of arctic vegetation history to understand how fauna had changed with animals and humans.
Historically, the belief is that the ice age's landscape was covered by largely grass-dominated systems -- called steppe. These grasses were replaced by mosses and other boggy vegetation when the ice age ended nearly 10,000 years ago, Craine said.
For the study, researchers visited museums in Alaska, Canada, Norway and Russia to collect DNA samples from inside the gut of frozen mammoths, bison, horses and rhinoceros that lived in the ice age.
Molecular techniques were used to look for plant DNA in each ancient animal's digestive tract. Plant DNA was then sequenced and reconstructed to differentiate wildflowers from grasses.
"Once the gut contents and soils started getting sequenced, they began finding lots more wildflowers than before," Craine said. "Nearly half of the digested plants were wildflowers. So, rather than having this really grassy, dull system like we believe existed, it suddenly was one that was very colorful."
The study challenges the view that the arctic landscape in the ice age was largely grasslands.
"Part of the scientific debate is knowing what the past looked like," Craine said. "There have always been debates about how a region that's so cold could have supported animals that were so large. Mammoths were huge and lived on these largely barren landscapes. Now we know that they were spending a lot of time eating wildflowers, which have a lot more protein in them than grasses, which means that they could support larger animals."
Craine helped interpret data and the consequences of losing bison and other grazing animals over thousands of years in parts of the world.
Although the findings reframe 50,000 years of the past, they also are applicable to predicting the future, Craine said.
Animals' grazing and climate changes stressed and eventually reshaped the vegetation in the tundra from wildflowers and grasses to moss and marshes, he said.
"The work is important because we can use the past to help us predict the future," Craine said. "But the work really makes us reevaluate how well we understand the diets of modern animals. If we misunderstood what bison and mammoths ate 15,000 years ago, maybe we should look more closely at what bison and elephants eat today. We just might find new surprises."
INFORMATION: END
Ice age's arctic tundra lush with wildflowers for woolly mammoths, study finds
2014-02-07
ELSE PRESS RELEASES FROM THIS DATE:
Bottom-up insight into crowd dynamics
2014-02-07
Stampedes unfortunately occur on too regular a basis. Previously, physicists developed numerous models of crowd evacuation dynamics. Their analyses focused on disasters such as the yearly Muslim Hajj or of the Love Parade disaster in Germany in 2010. Unfortunately, the casualties at these events may have been linked to the limitations of the crowd dynamics models used at the time. Now, a new study outlines a procedure for quantitatively comparing different crowd models, which also helps to compare these models with real-world data. In a paper published in EPJ B, Vaisagh ...
Researchers use genetic signals affecting lipid levels to probe heart disease risk
2014-02-07
New genetic evidence strengthens the case that one well-known type of cholesterol is a likely suspect in causing heart disease, but also casts further doubt on the causal role played by another type. The findings may guide the search for improved treatments for heart disease.
Most of us have heard of "good cholesterol" and "bad cholesterol" coursing through our bloodstream. In the conventional health wisdom of the past 30 years, having more of the "good" variety (high-density lipoprotein, or HDL) lowers your risk of heart disease, while more of the bad one (low-density ...
Shape-sifting: NIST categorizes bio scaffolds by characteristic cell shapes
2014-02-07
Getting in the right shape might be just as important in a biology lab as a gym. Shape is thought to play an important role in the effectiveness of cells grown to repair or replace damaged tissue in the body. To help design new structures that enable cells to "shape up," researchers at the National Institute of Standards and Technology (NIST) have come up with a way to measure, and more importantly, classify, the shapes cells tend to take in different environments.*
With the notable exception of Flat Stanley, we all live, and are shaped by, a 3-dimensional world. Biologists ...
Computer models help decode cells that sense light without seeing
2014-02-07
Researchers have found that the melanopsin pigment in the eye is potentially more sensitive to light than its more famous counterpart, rhodopsin, the pigment that allows for night vision.
For more than two years, the staff of the Laboratory for Computational Photochemistry and Photobiology (LCPP) at Ohio's Bowling Green State University (BGSU), have been investigating melanopsin, a retina pigment capable of sensing light changes in the environment, informing the nervous system and synchronizing it with the day/night rhythm. Most of the study's complex computations were ...
Variability of contact precaution policies in US emergency departments
2014-02-07
In a study published in Infection Control and Hospital Epidemiology on February 7, 2014, Daniel J. Pallin, MD, MPH and Jeremiah D. Schuur, MD, MS, surveyed a random sample of US emergency departments (EDs) and found substantial variation in the adoption of policies relating to contact precautions.
While most EDs have policies relating to contact precautions when specific organisms are suspected, a minority have such policies for the symptoms often caused by those organisms. This indicated that institutional policies do not mirror consensus recommendations by the CDC, ...
Panel issues report on gray wolf science
2014-02-07
(Santa Barbara, Calif.) — As the Endangered Species Act (ESA) celebrated its 40th anniversary at the end of 2013, its administrative agency, the U.S. Fish and Wildlife Service (USFWS), was mired in controversy. At issue was a proposal to remove the gray wolf (Canis lupus) from the List of Endangered and Threatened Wildlife and add the Mexican gray wolf (Canis lupus baileyi).
As a result, the USFWS sought an independent peer review of the science behind the proposed rule to delist the gray wolf species. The agency commissioned UC Santa Barbara's National Center for Ecological ...
Study shows drop in crime rates are less where Wal-Mart builds
2014-02-07
Communities across the United States experienced an unprecedented decline in crime in the 1990s. But for counties where Wal-Mart built stores, the decline wasn't nearly as dramatic.
"The crime decline was stunted in counties where Wal-Mart expanded in the 1990s," says Scott Wolfe, assistant professor of criminology and criminal justice at the University of South Carolina and lead author of a new study. "If the corporation built a new store, there were 17 additional property crimes and 2 additional violent crimes for every 10,000 persons in a county."
The study, titled ...
Researchers at UGent and VIB, discovered potential novel treatment against septic shock
2014-02-07
Septic shock is caused by excessive and systemic reaction of the entire body against infectious agents, in most cases of bacterial origin. The number of deaths by septic shock in intensive care units is very high and is still increasing, despite numerous large scale clinical trials. Scientists of VIB and UGent, supervised by Peter Vandenabeele, demonstrated in a mouse study that a potential novel treatment for sepsis may consist of the simultaneous neutralization of two harmful cytokines in the blood circulation, namely interleukin-1 and interleukin-18.
In the VIB research ...
Dating is refined for the Atapuerca site where Homo antecessor appeared
2014-02-07
One of the issues of the Atapuerca sites that generates the most scientific debate is the dating of the strata where the fossils are found. Therefore, researchers at the Spanish National Research Centre for Human Evolution, among others, strive to settle the dates. A study published by the 'Journal of Archaeological Science' has clarified that the sediment of Gran Dolina, where the first remains of Homo antecessor were discovered in 1994, is 900,000 years old.
The findings at the Lower Palaeolithic cave site of Gran Dolina, in the Sierra de Atapuerca mountain range (Burgos), ...
Protein structure: Peering into the transit pore
2014-02-07
The lipid-rich membranes of cells are largely impermeable to proteins, but evolution has provided a way through – in the form of transmembrane tunnels. A new study shows in unmatched detail what happens as proteins pass through such a pore.
Every cell is surrounded by a surface membrane and contains internal compartments bounded by membranes. Almost one-third of all proteins synthesized in cells must pass through these membranes or be incorporated into them in order to fulfil their functions. However, the fat-rich nature of membranes makes it impossible for most proteins ...