Thursday, January 12, 2017

The Black Death: Ecological Invasion Resembles a Drunken Walk More so Than Waves

From Ideas, Inventions And Innovations:
A theory that uses the mathematics of a drunken walk describes ecological invasions better than waves, according to Tim Reluga, associate professor of mathematics and biology, Penn State.

The ability to predict the movement of an ecological invasion is important because it determines how resources should be spent to stop an invasion in its tracks. The spread of disease such as the black plague in Europe or the spread of an invasive species such as the gypsy moth from Asia are examples of ecological invasions.

Two camps of scientists work on this problem — mathematicians and ecologists. Mathematicians focus on creating models to describe invasion waves, while ecologists go to the field to measure observations of invasions, building computer simulations to predict the phenomenon they observe. Ideally both camps should agree on the underlying theory to explain their model results. But an ongoing argument continues among these scientists due to one seemingly simple detail — how randomness affects an ecological invasion. Reluga hopes his approach will settle the argument, reconciling mathematical models with ecological observations.
Animation showing the spread of The Black Death from 1346 through to 1351
https://3.bp.blogspot.com/-84Vf2zE44gI/WHX9gUxOTaI/AAAAAAABSdU/PAz2cnI12b8Jblfy-X_JL72956CkBdXcgCLcB/s1600/Spread-Of-The-Black-Death.gif
"I hope this paper makes things clear that different kinds of randomness have different effects on invasions," Reluga said.

Previously, ecologists made inconsistent theories about how randomness influences an invasion. Some said it sped up while others said it slowed down an invasion...MORE
Previously in randomness:
Randomness: "A Drunkard’s Walk in Manhattan"
The Man Who Invented Modern Probability: Chance encounters in the life of Andrei Kolmogorov.
Profiting From Random Strategies
Computer Simulations Reveal Benefits of Random Investment Strategies Over Traditional Ones
Okay, Enough With Politics: Attention Managers, You Can Improve Corporate Efficiency by Randomly Promoting Employees
That last piece of research was awarded Harvard's own Ig Nobel prize in 2010.
Ya see, ya got your complex systems and ya got your chaotic systems and then ya got your complex-chaotic systems like weather or the economy or the stock market and when you endeavor at those levels of sophistication you realize:...
Should You Just Give Up And Trade Stocks Randomly?
Joys of Noise: Technologies that Rely on Randomness
Think a coin toss has a 50-50 chance? Think again.
What Were the Odds That Legg Mason's Bill Miller Would Achieve the Results That He Did?

And dozens more, use the search blog box if interested.