For the first time ever mathematicians have modelled all the different possible relationships between nutrients and biodiversity in lab-based experimental ecosystems. They found that although nutrient availability definitely has an impact on biodiversity, the precise relationship between the two depends on which species are present in the ecosystem. This means that in some cases low levels of nutrients can lead to high levels of biodiversity.
The new study involved biologists from the University of California Santa Cruz running a lab experiment to find out how different levels of nutrients affected how many species evolved in an ecosystem. Mathematicians from Imperial College London and the University of Bath then devised a model to show how far the results could be applied to real world scenarios.
The experiments set up by the biologists in the USA consisted of mini ecosystems full of E. coli bacteria and a parasite that lives on the E. coli. These simple communities of hosts and pathogens represent complex ecosystems in the real world, like forests, in which hosts such as trees live and evolve alongside pathogens such as fungi, bacteria and viruses.
The overall aim of the study was to shed new light on the mystery of why some ecosystems such as tropical rainforests are teeming with thousands of different plant species, whereas others, like the pine forests of northern Europe, support significantly fewer types of plant life. However, investigating this phenomenon in the field can be difficult, time consuming and results hard to interpret.
Instead, the researchers used the series of mini-ecosystems in the lab, which consisted of test tubes containing E. coli bacteria, a sugary Lucozade-like liquid for the E.coli to eat, and a parasite that lives on the E. coli.
To mimic different environments, the scientists varied the amount of sugar in each different ‘ecosystem’, and then recorded how many new strains of bacteria and parasite evolved in the sugary broth over the course of 150 generations, which took 17 days.
Their results showed that as the levels of sugar in the ecosystem changed, so did the extent to which new strains evolved. This experiment showed that the highest biodiversity resulted from a low level of nutrients.
Professor Laurence Hurst from the University of Bath’s Department of Biology explains: “The results in the lab showed that varying the level of sugary food in these mini-ecosystems caused the amount of biodiversity in the ecosystems to change. This suggests that the availability of nutrients is one of the factors that affect how many different plant species live in different parts of the world. This has been shown in a lab before, but what we wanted to do was use maths to show how these results, which refer to one kind of bacteria and its parasite, can be applied to other organisms and ecosystems in the real world.”
The team from Bath and Imperial constructed a model to work out whether this inverse relationship would be the same in all ecosystems – whether in the lab or in the real world. They found that although nutrients do affect biodiversity, the precise relationship between the two varies from one ecosystem to the next, depending on what species are present.
Dr Rob Beardmore from Imperial College London’s Department of Mathematics explains: “Although there was a clear link between nutrients and biodiversity in the lab, our mathematical model showed that in some ecosystems you will find that higher levels of nutrients lead to more biodiversity, which is opposite to what our biologist colleagues found in the lab. It turns out that the precise nature of this nutrient-diversity relationship varies from one ecosystem to another, and it depends on the complex interactions between species evolving alongside each other.”
The mathematical model can be used to predict what impact different levels of nutrients will have on biodiversity in any given lab-based ecosystem. The team say their results are very important for scientists who use small scale lab experiments to investigate phenomena in the real world.
The study also provides the first real evidence that a theory known as “geographic mosaic co-evolution hypothesis” holds up in real world ecosystems. Co-author on the paper, Dr Ivana Gudelj from Imperial College, explains: “This complicated-sounding theory basically says that nutrient availability will only have an impact on the diversity of an organism, if the organism is involved in a co-evolutionary arms race with pathogens or competitors, like our E.coli was with its parasite. Our biologist colleagues have shown evidence for this in the lab, and our mathematical model suggests that the theory will also hold up in real world ecosystems too.”
Abigail Smith | alfa
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
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