Ancient soil-inhabiting creatures decreased in body size by nearly half in response to a period of boosted carbon dioxide levels and higher temperatures, scientists have discovered.
The researchers' findings are published in the October 5, 2009, early online edition of the journal Proceedings of the National Academy of Sciences (PNAS).
Jon Smith, a scientist at the Kansas Geological Survey, and Stephen Hasiotis, a geologist at the University of Kansas, have demonstrated that soil-inhabiting creatures contracted in size by 30-46 percent during the Paleocene-Eocene Thermal Maximum (PETM).
The PETM was a short interval 55 million years ago marked by a spike in the atmosphere's carbon dioxide levels and global temperatures, conditions being repeated on Earth now.
The study is the first to establish that soil biota experienced a loss in size similar to mammals, which were reduced in size by as much as 50 percent during the PETM.
"The discovery that up to 50 percent of the body size reduction during the PETM was not just restricted to mammals, but also affected soil-dwelling organisms, has broad implications that may be very significant to understanding modern climate change and its impending effect on life," said H. Richard Lane. Lane is a program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research by Hasiotis and colleague Mary Kraus at the University of Colorado.
"In our initial hypothesis, we thought that there would be no response to climate change, that the animals would be protected because they're underground," said Hasiotis.
"We also proposed that there would be minimal and protracted change or some sort of a delayed response. Instead, we find that they did experience the same kind of change as vertebrates living during the same period."
The soil-dwelling organisms examined by Smith and Hasiotis are ancient relatives of modern ants, cicadas, dung beetles, earthworms and crayfish.
To establish their findings, the researchers examined trace fossils, or the burrows, nests, tracks, trails and borings of organisms preserved within the Willwood Formation, a thick sequence of mudstones and sandstones in Wyoming's Bighorn Basin.
They found that diameters of burrows and other traces were smaller during the PETM, suggesting that the soil-inhabiting organisms that had created the traces were correspondingly lesser in size.
The scientists say that their results foreshadow biological outcomes that may result due to the planet's current jump in carbon dioxide concentration and temperatures.
They suggest that museum collections of insects compiled over the last few hundred years should be studied to determine whether body sizes of modern insects are indeed getting smaller.
"The PETM is seen as a good analog for modern climate change because it's occurring at roughly the same speed and magnitude," said Smith.
"The take-home lesson is that there can be cascading effects that ripple through an ecosystem when you change just one aspect. Modern climate change can have many effects that aren't going to be as immediately visible as sea-level change.
"We could be changing soil conditions over vast portions of the world and affecting the soil organisms themselves--and that will impact our own agriculture."
The researchers attribute dwarfism in soil-dwelling creatures to faster rates of development in individuals, along with decreasing life spans.
"The soil biota evolved for certain soil temperatures and conditions--and for this geologically brief period of time, those conditions were changed," Hasiotis said. "They probably were adapting to those warmer conditions by having a smaller body size."
During their time in the Bighorn Basin, a typical day in the field for the researchers involved digging shoulder-width trenches that were a meter or so deep and several meters tall, then searching the soil for specific geometric shapes indicating ancient nests, cocoons and burrows.
"For each individual trace fossil, we'd measure the diameter," said Smith. "We'd compare like trace fossils from rocks that occurred before the PETM event, within the event, and after the event. Then we'd look for changes in those diameters through time."
"We were surprised to find that they were in fact smaller through the PETM."
Cheryl Dybas | EurekAlert!
Further reports about: > Ancient African Exodus > Climate change > Earth's magnetic field > PETM > Paleocene-Eocene Thermal Maximum > Science TV > biological outcomes > body size > carbon dioxide > carbon dioxide levels > cocoons > dioxide concentration > global temperature > soil-dwelling organisms > soil-inhabiting creatures
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
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...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences