Wednesday, July 26, 2017

The Central Question

The central question in biology today is how life originated. It's not only the biggest unanswered question in biology, but it's also central to our understanding of the place of life in the universe. We now know that planets are extremely common in the universe, and it's at least plausible, that a lot of them have or had Earth like conditions. If we understood how life originated on Earth, we would be much more able to understand the probability of it existing elsewhere. Conversely, if we found life elsewhere, it would almost certainly provide potent clues to how life originated on Earth.

The past decades have seen considerable progress in understanding some possibilities for early life, but we are far from concrete answers.

Natalie Wolchover, writing in Quanta, has some news on one approach, dissipation driven organization. The idea is that some physical systems evolve to maximize their dissipation of energy and entropy increase.

The biophysicist Jeremy England made waves in 2013 with a new theory that cast the origin of life as an inevitable outcome of thermodynamics. His equations suggested that under certain conditions, groups of atoms will naturally restructure themselves so as to burn more and more energy, facilitating the incessant dispersal of energy and the rise of “entropy” or disorder in the universe. England said this restructuring effect, which he calls dissipation-driven adaptation, fosters the growth of complex structures, including living things. The existence of life is no mystery or lucky break, he told Quanta in 2014, but rather follows from general physical principles and “should be as unsurprising as rocks rolling downhill.”

Since then, England, a 35-year-old associate professor at the Massachusetts Institute of Technology, has been testing aspects of his idea in computer simulations. The two most significant of these studies were published this month — the more striking result in the Proceedings of the National Academy of Sciences (PNAS) and the other in Physical Review Letters (PRL). The outcomes of both computer experiments appear to back England’s general thesis about dissipation-driven adaptation, though the implications for real life remain speculative.

We know lots of examples of dissipation driven organization in real non-living physical systems. The article mentions the Great Red Spot of Jupiter, but even more familiar examples are hurricanes or even ordinary thunderstorms. England's work seems to show that this kind of organization can take place at the atomic and molecular level, one essential for the production of the complex molecules of life.