Spiral Dynamics (SD) is a model of the evolutionary development of individuals, organizations, and societies. It was initially developed by Don Edward Beck and Christopher Cowan based on the emergent cyclical theory of Clare W. Graves, combined with memetics as proposed by Richard Dawkins and further developed by Mihaly Csikszentmihalyi.

You may remember from school the difference between an exergonicand an endergonic reaction. In the first case, you constantly need toadd energy to keep the process going. In the second case, thereaction, once triggered, continues by itself and even releasesenergy.

they found that the glyoxylate and pyruvate reacted to make a range of compounds that included chemical analogues to all the intermediary products in the TCA cycle except for citric acid. Moreover, these products all formed in water within a single reaction vessel, at temperatures and pH conditions mild enough to be compatible with conditions on Earth.

The situation changed in the late 1990s, when the physicists Gavin Crooks and Chris Jarzynski derived “fluctuation theorems” that can be used to quantify how much more often certain physical processes happen than reverse processes. These theorems allow researchers to study how systems evolve — even far from equilibrium.

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Any claims that it has to do with biology or the origins of life, he added, are “pure and shameless speculations.”

Ideas on how to analyze and predict network behavior have been informed by concepts arising from the computational and social sciences, which are themselves increasingly concerned with understanding networks. The interesting thing about these ideas is that they work at scales ranging from the molecular to the population level.

Criticality may be everywhere.

“DNA as Information” Theme issue compiled and edited by Cartwright, J.H.E., Giannerini, S., & Gonzalez, D.L. Philosophical Transactions of the Royal Society A 374 (2016).

When geneticists finally gained the power to cost-efficiently analyze entire genomes, they realized that most disorders and diseases are influenced by thousands of genes, each of which has a tiny effect. To reliably detect these miniscule effects, you need to compare hundreds of thousands of volunteers. By contrast, the candidate-gene studies of the 2000s looked at an average of 345 people!

In the meantime, the classification of viruses remains unclear. Tupanviruses seem to be dependent on their hosts for very little, and other viruses, according to one preprint, even encode ribosomal proteins. “The gap between cellular organisms and viruses is starting to close,” Deeg said.

“It’s remarkable that viruses seem to mingle into the translational domain so extensively,” said Matthias Fischer, a virologist at the Max Planck Institute for Medical Research in Germany who was not involved with either study.

As it happens, he’d already done some work on coding theory—in the area of biology. The digital nature of DNA had been discovered by Jim Watson and Francis Crick in 1953, but it wasn’t yet clear just how sequences of the four possible base pairs encoded the 20 amino acids. In 1956, Max Delbrück—Jim Watson’s former postdoc advisor at Caltech—asked around at JPL if anyone could figure it out. Sol and two colleagues analyzed an idea of Francis Crick’s and came up with “comma-free codes” in which overlapping triples of base pairs could encode amino acids. The analysis showed that exactly 20 amino acids could be encoded this way. It seemed like an amazing explanation of what was seen—but unfortunately it isn’t how biology actually works (biology uses a more straightforward encoding, where some of the 64 possible triples just don’t represent anything).

Through decades of work by legions of scientists, we now know that the process of Darwinian evolution tends to lead to an increase in the information coded in genes. That this must happen on average is not difficult to see. Imagine I start out with a genome encoding n bits of information. In an evolutionary process, mutations occur on the many representatives of this information in a population. The mutations can change the amount of information, or they can leave the information unchanged. If the information changes, it can increase or decrease. But very different fates befall those two different changes. The mutation that caused a decrease in information will generally lead to lower fitness, as the information stored in our genes is used to build the organism and survive. If you know less than your competitors about how to do this, you are unlikely to thrive as well as they do. If, on the other hand, you mutate towards more information—meaning better prediction—you are likely to use that information to have an edge in survival.

Walter Pitts was pivotal in establishing the revolutionary notion of the brain as a computer, which was seminal in the development of computer design, cybernetics, artificial intelligence, and theoretical neuroscience. He was also a participant in a large number of key advances in 20th-century science.

ITBio – Chris Aldrich (feed)

That mingling has sparked contentious debate among scientists about when and how giant viruses evolved. All of viral evolution is murky: Different groups of viruses likely had very different origins. Some may have been degenerate “escapees” from cellular genomes, while others descended directly from the primordial soup. “Still others have recombined and exchanged genes so many times in the course of evolution that we will never know where they originally came from,” Fischer said.