Suspending a life in time is a theme that normally finds itself in the pages of science fiction, but now such ideas have become a reality in the annals of science.
Cornell ecologist Nelson Hairston Jr. is a pioneer in a field known loosely as “resurrection ecology,” in which researchers study the eggs of such creatures as zooplankton – tiny, free-floating water animals – that get buried in lake sediments and can remain viable for decades or even centuries. By hatching these eggs, Hairston and others can compare time-suspended hatchlings with their more contemporary counterparts to better understand how a species may have evolved in the meantime.
The researchers take sediment cores from lake floors to extract the eggs; the deeper the egg lies in the core, the older it is. They then place the eggs in optimal hatching conditions, such as those found in spring in a temperate lake, and let nature take its course.
“We can resurrect them and discover what life was like in the past,” said Hairston, who came to Cornell in 1985 and is a professor and chair of Cornell’s Department of Ecology and Evolutionary Biology. “Paleo-ecologists study microfossils, but you can’t understand much physiologically or behaviorally” with that approach, he said.
Hairston first became interested in the possibilities of studying dormant eggs in the late 1970s, when he was an assistant professor of zoology at the University of Rhode Island. There, he noticed that the little red crustaceans – known as copepods – in the pristine lake behind his Rhode Island home disappeared in the summer, only to return as larvae in the fall.
The observation prompted him to study why they disappear, research that revealed the copepods stay active under the ice in the winter, but they die out as their eggs lie dormant on the lake floor through the summer when the lake’s fish are most active. When the fish become less active in the fall, larvae hatch from the eggs, and the copepods continue their life cycle.
This time suspension, where zooplankton pause their life cycles to avoid heavy predation or harsh seasonal and environmental conditions, also increases a species’ local gene pool, with up to a century’s worth of genetic material stored in a lake bed, Hairston said. When insects, nesting fish and boat anchors stir the mud, they can release old eggs that hatch and offer a wider variety of genetic material to the contemporary population.
In 1999 Hairston and colleagues published a paper in Nature that described how 40-year-old resurrected eggs could answer whether tiny crustaceans called Daphnia in central Europe’s Lake Constance had evolved to survive rising levels of toxic cyanobacteria, known as blue-green algae. In the 1970s, phosphorus levels from pollution rose in the lake, increasing the numbers of cyanobacteria. The researchers hatched eggs from the 1960s and found they could not survive the toxic lake conditions, but Daphnia from the 1970s had adapted and survived.Hairston and colleagues have organized a resurrection ecology symposium in
Blaine Friedlander | Newswise Science News
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine