This finding suggests that quick-growing plants such as weeds may cope better with global warming than slower-growing plants such as Redwood trees -- a phenomenon that could lead to future changes in the Earth's plant life.
"Some species evolve fast enough to keep up with environmental change," said Arthur Weis, professor of ecology and evolutionary biology. "Global warming may increase the pace of this change so that certain species may have difficulty keeping up. Plants with longer life cycles will have fewer generations over which to evolve."
The study appears the week of Jan. 8 in the Proceedings of the National Academy of Sciences.
Weis and researchers Steven Franks and Sheina Sim studied field mustard, a weedy plant found throughout the Northern Hemisphere. In a greenhouse, they grew mustard plants at the same time from seeds collected near the UCI campus in the spring of 1997 -- two years before a five-year drought -- and seeds collected after the drought in the winter of 2004. Seeds can remain dormant but alive for years and be revived with a little water and light. The plants were divided into three groups, each receiving different amounts of water mimicking precipitation patterns ranging from drought to very wet conditions. In all cases, the post-drought generation flowered earlier, regardless of the watering scheme.
This shift in genetic timing was further confirmed with an experiment that crossed the ancestors and descendents. As predicted, the intergenerational hybrids had an intermediate flowering time.
"Early winter rainfall did not change much during the drought, but the late winters and springs were unusually dry. This precipitation pattern put a selective pressure on plants to flower earlier, especially annual plants like field mustard," Franks said. "During drought, early bloomers complete seed production before the soil dries out, whereas late bloomers wither before they can seed."
The technique of growing ancestors and descendents at the same time allowed the scientists to determine that the change in flower timing was in fact an evolutionary shift -- not a simple reaction to changing weather conditions. This method, pioneered by Albert Bennett, professor of ecology and evolutionary biology and acting dean of the School of Biological Sciences at UCI, has been used with bacteria, but this is the first study to make full use of it with a plant species. Bennett and his colleagues froze ancestral strains of E. coli so they could evaluate the bacterium's adaptive evolution after culturing it at elevated temperatures for thousands of generations.
Today, Weis is the organizing chairman of Project Baseline, a national effort to collect and preserve seeds from contemporary plant populations. Decades from now, plant biologists will be able to "resurrect" these ancestral generations and compare them to their descendents. By that time, advanced DNA technology may make it possible to sequence the entire genome of individual plants and at low cost. If so, biologists will be able to measure how much plants have evolved with climate change and pinpoint the evolution's underlying genetic basis.
Scientists expect global warming to alter air circulation patterns over the Pacific Ocean, and climate models predict frequent and extreme fluctuations in precipitation along the coast, which likely will affect plant life.
"If we go out today and collect a large number of seeds and freeze them, they will be a resource available to the next generation of scientists," Weis said. "Because of global warming, the evolution explosion is already under way. If we act now, we'll have the tools necessary to determine in the future how species respond to climate change."
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
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,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy