Saturday, September 13, 2014

"The Thermodynamic Theory of Ecology"

Our boilerplate intro to Quanta Magazine:
The Simons Foundation is Jim Simons' baby, originally conceived to fund research in mathematics (Mr. Simons' specialty), the foundation has expanded its areas of interest to all basic science.
They put out a magazine called Quanta which we last visited in "Data Driven: The New Big Science: Chapter 4 Biology in the Era of Big Data".

Mr. Simons was the premier global macro quant with his Renaissance Technologies Medallion Fund averaging 35% per annum (after fees, which are a post unto themselves) since 1989.
Mr. Simons retired in 2009. In 2013 RenTech was up 18%, trailing the S&P by 12 points but stomping on the average hedge fund's 7.4% return.
All that being said, it is actually Marilyn Simons who is the motive force.
From Quanta:
Insights from information theory illuminate nature’s large-scale patterns.
MaxENT_Ari_Weinkle_Lead_Illo
The Western Ghats in India rise like a wall between the Arabian Sea and the heart of the subcontinent to the east. The 1,000-mile-long chain of coastal mountains is dense with lush rainforest and grasslands, and each year, clouds bearing monsoon rains blow in from the southwest and break against the mountains’ flanks, unloading water that helps make them hospitable to numerous spectacular and endangered species. The Western Ghats are one of the most biodiverse places on the planet. They were also the first testing ground of an unusual new theory in ecology that applies insights from physics to the study of the environment.

John Harte, a professor of ecology at the University of California, Berkeley, has a wry, wizened face and green eyes that light up when he describes his latest work. He has developed what he calls the maximum entropy (MaxEnt) theory of ecology, which may offer a solution to a long-standing problem in ecology: how to calculate the total number of species in an ecosystem, as well as other important numbers, based on extremely limited information — which is all that ecologists, no matter how many years they spend in the field, ever have. Five years ago, the Ghats convinced him that what he thought was possible from back-of-the-envelope calculations could work in the real world. He and his colleagues will soon publish the results of a study that estimates the number of insect and tree species living in a tropical forest in Panama. The paper will also suggest how MaxEnt could give species estimates in the Amazon, a swath of more than 2 million square miles of land that is notoriously difficult to survey.
John Harte thinks it is possible to predict the behavior of ecosystems using just a few key attributes. His method ignores nature’s small-grained complexities, which makes many ecologists skeptical of the project.
Mary Ellen Harte
John Harte thinks it is possible to predict the behavior of ecosystems using just a few key attributes. His method ignores nature’s small-grained complexities, which makes many ecologists skeptical of the project.
If the MaxEnt theory of ecology can give good estimates in a wide variety of scenarios, it could help answer the many questions that revolve around how species are spread across the landscape, such as how many would be lost if a forest were cleared, how to design wildlife preserves that keep species intact, or how many rarely seen species might be hiding in a given area. Perhaps more importantly, the theory hints at a unified way of thinking about ecology — as a system that can be described with just a few variables, with all the complexity of life built on top.

The Big Picture
Harte has an impressive track record as an ecologist. But before he entered the field, he was trained as a theoretical physicist. In his first faculty job 46 years ago, he taught thermodynamics at Yale University. “That’s when I first really became enamored of the foundations of thermodynamics and statistical physics, when I realized the power of the ideas that those theories are based on,” he said. In particular, he was fascinated by the idea that you could look at, say, a container of hydrogen and infer micro values, like the velocities of the molecules, from macro values like temperature and volume.

But he soon left to become an ecologist, studying the effect of acid rain on salamanders. Twenty-five years ago he began a landmark experiment at the Rocky Mountain Biological Laboratory, gradually heating up a subalpine meadow using electric heat lamps to simulate the climate of 2050 in order to discover what it will do to the soil and organisms found there. Thirty papers and nine doctoral theses have come out of the experiment, which is still running. “It’s been a major preoccupation of mine for a quarter of a century,” he said. About 15 years ago, however, he grew interested in macroecology, which deals with the search for large-scale patterns in ecosystems.

Ecologists study the connections between species and their environment, traditionally through detailed observations of the natural world. They might penetrate far into a rainforest, learning the calls of birds one by one until they identify one they’ve never heard before. They might, as Harte does, monitor a single meadow for decades, becoming deeply versed in the details of each creature’s existence. Many are also interested in high-level, abstract questions, such as how birds first began to flock. But the field is rooted in a kind of natural history.

Macroecology deals with patterns that might be universal across ecosystems. When the field arose in the 1970s, ecologists tried to model the environment as a well-oiled machine that, given enough time, would settle into certain patterns. Yet when it became clear how much messier the real world is than those models, the field went quiet. “We were trying to answer bigger questions than our data could support,” said William Kunin, a professor of ecology at University of Leeds in the U.K. who watched the field evolve as an undergraduate in the 1970s.

In the late 1990s and early 2000s, macroecology rose again, driven by the need to understand the effects of mass deforestation, climate change and other large-scale changes in the environment. “We’re in a situation where there are big global-scale trends in species distributions, in climates, in fertilization of the planet. We’re doing big things to the world,” said Kunin, who now does macroecology work. “And policymakers want from us answers of what that will do to biodiversity.” Vanessa Weinberger, a doctoral student at the Pontifical Catholic University of Chile who has interned with Harte, adds: “What these people started to do was to try to come up with laws of ecology.”...MUCH MORE
Also at Quanta:
At Multiverse Impasse, a New Theory of Scale
Mass and length may not be fundamental properties of nature, according to new ideas bubbling out of the multiverse.
Previously:
"The Future Fabric of Data Analysis"
Making A Better Model of the Market: Are Financial Markets an Aspect of the Quantum World?
"As Machines Get Smarter, Evidence They Learn Like Us"
The Game Theory of Life or Why the Weak Survive
And many more.