Entropy is a greased pole, but some researchers believe they can climb it. The fundamentals of thermodynamics were discovered in the 19th century, establishing some of the best-confirmed laws in all of science. Mathematician Granville Sewell has argued in these pages that evolutionary theory is at crosscurrents with the second law of thermodynamics (the law of entropy), dooming it to failure.
Every once in a while, though, a physicist or biologist tinkers with the laws, looking for ways to skirt their implications. Here are three recent examples.
In PLoS Biology this month, a team of physicists and biologists discuss "Thermodynamic System Drift in Protein Evolution" in thermophilic bacteria. How do heat-loving bacteria overcome the tendency to unfold ("melt") at the high temperatures they call home? What keeps them stable? The authors believe that natural selection helped them navigate the solutions:
We observed that, while the Tm [melting temperature] changes smoothly, the mechanistic basis for stability fluctuates over evolutionary time. Thus, even while overall stability appears to be strongly driven by selection, the proteins explored a wide variety of mechanisms of stabilization, a phenomenon we call "thermodynamic system drift." This suggests that even on lineages with strong selection to increase stability, proteins have wide latitude to explore sequence space, generating biophysical diversity and potentially opening new evolutionary pathways. (Emphasis added.)
Unexpectedly, the paper never mentions the second law, entropy, or order. Nor does Richard Robinson in his review of the paper in PLoS Biology. Even though they attribute protein "evolution" in thermophiles to natural selection, it appears they are only talking about stabilizing selection: processes that keep existing structures from degrading.
Since nothing functionally new is innovated by unguided processes, this does not appear to contradict anything that design advocates would accept. Indeed, the authors were aware that "The biophysical properties of proteins must adjust to accommodate environmental temperatures because of the narrow range over which any given protein sequence can remain folded and functional." Also, the paper talks about "evolutionary intermediates" between non-thermophiles and thermophiles, but these were inferred on their computers, not found in the wild.
A report from Berkeley Labs claims a team was able to "produce nanostructures that have historically been considered impossible to assemble." Under the headline "Outsmarting Thermodynamics in Self-assembly of Nanostructures," Rachel Berkowitz says the physicists overcame "top-down" assembly, which they consider inefficient and costly, with a "bottom up" route. By introducing a feedback mechanism, they were able to break the natural symmetry of building blocks in solution, and build their "desired structure," colloidal gold nanorods. The method involved a laser:
The team used a laser to excite the plasmonic resonance of specific particles produced in the reaction. This allowed them to separate out the un-desired resonances, indicating nanorod pairs that are not shifted the desired amount, and dissociate those pairs using heat from the excitation.
"Only the desired resonance survives in this process," Ni says. "Then the reaction can be repeated to produce more of the desired, broken-symmetry particles based on their plasmonic signature. Clear distinction in resonance profiles makes this a highly selective method.
It’s not difficult to lower entropy — not difficult, that is, for an intelligent agent. An intelligent cause can direct its energy to push a ball uphill, when its natural thermodynamic tendency would be to roll downhill. None of this is a violation of thermodynamics; it’s just "outsmarting" it through purposive action. Even though the team spoke of evolution, they recognize that design was the key to getting "the desired" result. "In contrast to the conventional wisdom that a material’s structure determines its properties, we provocatively suggest that the physical properties of materials, by design, may dictate the evolution of self-assembly and self-determine the structures of bulk materials," the team lead says.
Disorder + Disorder = Order?
A news item from the American Institute of Physics teases us with the counterintuitive suggestion that you can get order by applying disorder to disorder.
If you took the junk from the back of your closet and combined it with the dirty laundry already on your floor, you would have an even bigger mess. While this principle will likely always hold true for our bedrooms, it turns out that in certain situations, combining messes can actually reduce the disorder of the whole. An international team of researchers from Slovenia and Iran has identified a set of conditions in which adding disorder to a system makes it more orderly. This behavior is known as antifragility, a concept introduced recently to describe similar phenomena in statistics, economics and social science.
The scientists distinguish between "thermodynamic disorder" (entropy) and "structural disorder" (defects in an idealized system). Under certain circumstances, those kinds of disorder are not additive. Their example was pretty specific: "the interaction between the structural disorder of charged surfaces and the thermal disorder of Coulomb fluids — collections of mobile charged particles, either ions or larger molecules, that interact with each other." Don’t try this in the laundry room:
Unfortunately, the finding won’t revolutionize our approach to cleaning anytime soon. "This only works for certain cases and under certain conditions," Naji said. "We find out that the disordered charges have to interact strongly with the mobile charges in the Coulomb fluid in order to have this behavior." However, the researchers eventually hope to identify these systems in areas more directly applicable to human lives.
Once again, though, this is not a violation of thermodynamics, and it takes intelligence to counteract the inexorable trend toward increasing entropy: "Chaos is not necessarily bad for us if we know how to counteract it with a little properly applied disorder of our own." The physicists made no applications to biology or evolution.
Indeed, none of these examples pertain to Darwinian evolution, which requires the creation of new complex specified information. The laws of thermodynamics stand, and the few examples of "outsmarting" them require intelligent agents with goals in mind.