Friday, January 27, 2012

Trade-Offs In Evolvability

"[T]he main and broadly applicable effect of fluctuating selection on the evolution of gene regulatory networks that allow for a feedback loop is selection for specific system dynamics that confer an increased evolvability. Increased evolvability mainly results from evolution of system parameters controlling the feedback loop, into a nonlinear regime, where both phenotypic diversity and the amount of phenotypic shift caused by individual mutations are increased."
More here. To the extent that you expect your environment to change a lot (i.e., undergo "fluctuating selection"), you should prefer meta-level approaches which allow you to change your object-level strategy more quickly and less costly. To the extent that you expect your environment to remain constant, this ability and propensity to change will be a hindrance.

Saturday, January 21, 2012

A Separation

Finally it has come out in Bethesda! Spoiler alert, you can view it as a delectable set of plausible moral quandaries wrapped up in a family drama. You can also view it as a demonstration of how external stressors are what really kill relationships. My favorite line was, naturally, "what is wrong is wrong, no matter who said it or where it's written."


Completely unrelated, this is the funniest thing I've read so far this calendar year. Anything for science. 

Sunday, January 1, 2012

Seven Ideas From 2011

One Idea For Trepidation

1) U.S. Life Expectancies Stagnate: In more than 20% of counties, life expectancies for women declined between 1997 and 2007, driven largely by increased rates of smoking and high blood pressure. In some senses this is not unexpected, as the century-long gains in lifespan in developed nations have been more a story of asymptotically approaching the maximum human lifespan rather than pushing it back. And healthiness during one's lifespan is to some people the most important measure. Still, this is a major worry, and all of the other ideas on this list must be tainted by this one. (see here and here for more)

county-wide change in life expectancies over recent decades, left is males and right is females, green is positive and red is negative; doi:10.1371/journal.pmed.0050066 

Four Ideas For Optimism

2) Chip-Based Neuronal Nets: Memristors are circuit elements that can "remember" their resistance state even in the absence of curent. They open up a wealth of potential applications, including directly mimicking synaptic learning rules. The first implementation of the memristor is now slated for commercial release in less than two years. (see here, here, and here for more)

certain memristor architectures can store the topology of a maze in the state of its switches and thus allow all of the memristors to participate in the path calculation at once;

3) Altering DNA More Precisely. Zinc finger nucleases are proteins that can be engineered to target and cut a particular DNA sequence, thus allowing for manipulation of (human) genomes. This year a set of breakthroughs were announced which allow for researchers to query the specificity of ZFN's across the genome. This is crucial, because you really want to minimize any chance for error when you might accidentally mutate a tumor suppressor gene. The only clinical trial I know of with these is for HIV, which seems to have had some promising albeit highly preliminary results. (see herehere, and here for more)

a model of a zinc finger nuclease; doi:10.1186/1471-2164-12-83

4) Downloadable Sneakers. What will be the "killer app" of 3D printing that makes everybody want one as badly as they first wanted a personal computer? It's unclear, but the initial spread of the tech is already upon us, and the events of this year have me more convinced that it will prove similarly disruptive. (see here and here for more)

photo by photon

5) The End Of Drunk Driving. What if your smartphone could double as your chauffeur? Amazingly, we already have the basic autonomous driving capabilities. The most important reasons to care about this are a) the number of lives it could save and b) the amount of time it could free up. Yes, there are plenty of downsides, but they must be weighed at every step against these upsides. (see here, here, and here for more)

photo by jurvetson

Two Ideas To Think About

6) The Dimensions Of The DSM-5. To what extent will the dimensional approach to mental disorders make it into the next draft of the bible of psychiatry? This is not purely academic. Rating patients by the significance of their disorder would help eliminate arbitrary thresholds between the healthy and pathological. But if the switch is made too soon, before the levels can be validated, then it could turn into a bonanza of overmedication. (see here and here for more)

photo by ecstaticist

7) The Apogee Of The Corporation. As self-employment rises and technology advances, a smaller and smaller chunk of economic activity is being dictated by firms. Our very notions of the corporation and the employee seem to be on their way out, and perhaps they will be replaced by something that makes more sense for the society of tomorrow. (see here and here for more)

a network representation of strongly connected transnational corporations;  doi:10.1371/journal.pone.0025995; how long can or will they last?