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LOW COMPLEXITY START. “Such systems are typically modeled as localized individuals that reproduce in an error-prone process, with their offspring weeded out in competitions with other individuals that select for higher complexity. In this natural selection process the individuals in a line of biological descent increase their complexity in time.” https://lnkd.in/euEN3Eh View in LinkedIn

AT THE EFFICIENCY LIMIT? “It may be that Rubisco is as good as it can get; as Tcherkez et al. note “all ribulose bisphosphate carboxylases may be near perfectly optimized”. Such examples as Rubisco are a useful reminder of some under-appreciated realities: even what appears to be disastrously maladaptive – who, after all would design an enzyme that is disabled by the very substance (oxygen) it helps to produce? – may still be as good as is possible.” https://lnkd.in/euEN3Eh View in LinkedIn

STARTING POINT. “It seems that many systems both increase their complexity if initialized in a low complexity state, and then reliably and robustly maintain high (but finite) complexity once it is attained. Some of the most prominent examples are the many biological systems undergoing natural selection that seem to start with low complexity and then increase their complexity.” https://lnkd.in/euEN3Eh View in LinkedIn

ENZYME LIMITS. “Take the protein Rubisco, of central importance in photosynthesis where as a carboxylase it acts as the enzyme central to the fixation of carbon. Yet, as is well-known, its rate of activity is cripplingly slow, explaining why it is the most abundant protein on the planet. It is difficult to think of an example where even a modest improvement in efficiency would not be adaptively highly significant, yet the only solution appears to be by rampantly convergent methods of carbon dioxide concentration, be they by carboxysomes.” https://lnkd.in/euEN3Eh View in LinkedIn

SATURABLE OPTIONS. “Convergent evolution, which happens often, and concludes that the space of phenotypes is “saturable” and has been quite saturated by evolution.” https://lnkd.in/euEN3Eh View in LinkedIn

CLOSE TO LIMITS. “The evidence actually suggests otherwise, and in doing so indicates that, with one crucial exception, not only is there a limit to biological complexity but in a way analogous to the extremophiles these limits may be close to being reached.” https://lnkd.in/euEN3Eh View in LinkedIn

UNLIMITED LIMITS. “Not only will we not make all possible proteins of length 200 or 2000, we will not make all possible organs, organisms, social systems, . . . There is an indefinite hierarchy of non-ergodicity as the complexity of the objects we consider increases.” https://lnkd.in/euEN3Eh View in LinkedIn

LIMITS OF TIME. “In short, in the lifetime of our universe, only a tiny fraction of all possible proteins of length 200 can have been created. This means profound things.” https://lnkd.in/euEN3Eh View in LinkedIn

GIANT POPULATIONS. "An important aspect of the quasispecies concept is that the large size of virus populations enables positive and negative interactions between individual viruses to establish a quasi-equilibrium of the variant proportions. Genetic variation is generated by the accumulation of mutations during replication and their re-arrangement by genetic recombination, and genome segment reassortment in the case of segmented genomes." http://www.sciencedirect.com/science/article/pii/S0042682215001580 View in LinkedIn

DARWINIAN VIEW. "Viral quasispecies are currently defined as collections of closely related viral genomes subjected to a continuous process of genetic variation, competition among the variants generated, and selection of the most fit distributions in a given environment." http://www.sciencedirect.com/science/article/pii/S0042682215001580 View in LinkedIn