Book preview- Natural Novelty: The newness manifest in existence

I have written a book about why new things happen.

Here is a preview containing the preface, contents, abstract-like summaries of each chapter, and the final conclusion. The full book, published by University Press of America, will be available on amazon etc from January 2016. Thank you for your interest.

Cover image (copyright NASA)
Cover image (copyright NASA)


Chicken-egg issues concerning the evolution of eukaryotic cells (paper in press)

Review of hypotheses attempting to explain how and why eukaryotes originated from prokaryotic ancestors. Major theme is the exceptional nature and scale of the change, which lends weight from an evolutionary point of view to the notion that the Proterozoic Earth system must have in some way been “special” in terms of its disposition to produce evolutionary novelty. Discusses a “chicken and egg” problem, whereby respiratory electron transport in multiple mitochondria allows increased free energy availability per cell, which allows an energetically demanding cytoskeleton to be supported – but faces the issue that symbionts are difficult to acquire without phagocytosis, which requires a cytoskeleton in the first place. Suggests a “bottleneck” scenario, in which free living proto-eukaryotes are forced spatially/temporally together, may have increased the probability of endosymbiosis, potentially in connection with the Paleoproterozoic glaciation events.

(Boyle, R.A. “The problem of Eukaryotic origins in relation to the Early/Mid Proterozoic Earth system” Book Chapter, Revolutions in the Early Proterozoic: Tracking Geochemical and Geobiological Change, “Topics in Geobiology”, In Press.)


the significance of animals stirring up mud

Makes the point that bioturbated sediments, ancient and modern, retain more organic phosphate per unit organic carbon than do non-bioturbated sediments (due to microbial polyphosphate sequestration in the oxygen-exposed sediments that result from bioturbation). Because bioturbation evolved at a definable point in time during the early Cambrian, this implies the origin of a concurrent phosphate sink. This in turn implies an oxygen decrease, because oxygen is produced by burial of reduced organic carbon, production of which is limited by phosphorus over long timescales. The oxygen/phosphate decreases were quantified relative to other relevant parameters (weathering, CP ratio of non-bioturbated sediments etc), and a feedback loop was suggested whereby the oxygen decrease induced by bioturbation is self-limiting, because bioturbation-causing animals require oxygen.


Constraints on the chemical composition of the ancient oceans

Addresses the problem of reconciling a Proterozoic “Canfield ocean” scenario (with globally significant euxinia), with the relatively rarity of pyrite-enriched reactive iron during this interval. Uses a simple box model to illustrate how the “electron tower principle” implies that globally significant sulphate reduction necessitates equivalently globally significant nitrate depletion (because denitrifiers will outcompete sulphate reducers). Proposes two distinct geochemical regimes for the low oxygen Proterozoic ocean (nitrate rich/ferruginous and nitrate depleted/euxinic), the latter of which may be partially reverted to in nitrate/oxygen depleted modern day upwelling zones. Suggests that a future empirical cross referencing exercise should find the iron speciation evidence for euxinia to be out of phase in time, with nitrogen isotope evidence for denitrification.


The evolution of recycling (even when its costly)

Addresses the question of why a circular nutrient recycling loop might be produced in a natural environment by two different physiologies, given that it seems just as likely that biology might evolve to degrade a nutrient into a unusable form that leaks out of the system. We applied principles from theoretical biology, concerning the evolution of cooperation (which is promoted by intermediate population mixing and patchy environments), in a simulated agent-based system. We found that in certain spatially structured environments a recycling loop can spread, even when the organisms that produce it are competitively inferior to organisms that “break” the loop by degrading a nutrient into an unusable form that leaks out of the system.


Does symbiosis bias towards climatic regulation?

Addresses the question of why a system conducive to homeostasis (two opposing feedback influences with the same intermediate optimum conditions for growth/expansion, referred to as “integral rein control”) should arise, and whether there is anything about life that biases towards the production of such a system? The hypothesis expressed in this paper is that symbiosis, on average, tends to bring together physiologies with distinct impacts on the natural environment but shared optimal conditions for growth. This tends to bias towards the feedback structure shown to be conducive to homeostasis by the original daisyworld model. This is expressed by introducing a symbiosis between a black and white daisy into the model – with the result of an extension of the habitable range within the system, and succession type dynamics in which the symbiosis colonises the system first but is then displaced due to the evolutionary cost of co-operation.


PhD Thesis: Theoretical feedbacks between Neoproterozoic glaciations and eukaryotic evolution

Incorporating the two multi-level selection/altruism papers below, as well as (i) carbon cycle modelling of ocean acidification in snowball earth conditions (importance of atmosphere-ocean chemical continuity in duration of glacial interval), (ii) quantitative assessment of the position (in temperature “space”) of the unstable region of the ice albedo feedback with respect to glacial entry and duration, (iii)

temperature sensitivity of terrestrial silicate weathering flux (in relation to susceptibility to snowball earth glaciation).