This paper suggests that the energy flow on which all living structures depend only started up slowly, the low-energy, initial phase starting up a second, slightly more energetic phase, and so on. In this way, the build up of the energy flow follows a bootstrapping process similar to that found in the development of computers, the first generation making possible the calculations necessary for constructing the second one, etc. In the biogenetic upstart of an energy flow, non-metals in the lower (...) periods of the Periodic Table of Elements would have constituted the most primitive systems, their operation being enhanced and later supplanted by elements in the higher periods that demand more energy. This bootstrapping process would put the development of the metabolisms based on the second period elements carbon, nitrogen and oxygen at the end of the evolutionary process rather than at, or even before, the biogenetic event. (shrink)

This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According to the first approach, life would have begun with—often organic—compounds. After having developed to a certain level of complexity and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast, the second, physical type of (...) approach has life developing within tiny compartments from the beginning. It emphasises the importance of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary, “ life ” would not have begun, nor have been maintained; this boundary—and the complex cell membrane that evolved from it—forms the essence of life. (shrink)

In my response to the paper by Jagers op Akkerhuis, I object against giving definitions of life, since they bias anything that follows. As we don’t know how life originated, authors characterise life using criteria derived from present-day properties, thus emphasising widely different ones, which gives bias to their further analysis. This makes their results dependent on their initial suppositions, which introduces circularity in their reasoning.

We analyse theories and research approaches in ecology and find that they fall into two internally homogeneous groups of linked ideas, each comprising a unique set of premises. The two sets of interpretive statements are thus mutually exclusive; they constitute alternative theoretical developments in ecology and should not be seen as complementary. They can, therefore, be considered two paradigms (Kuhn, 1962). Our interpretation is supported by the minimal overlap, if any, in the premises and research directions of the two approaches. (...) We label the dominant group of ideas the demographic paradigm and the less developed one the autecological paradigm. The internal logic of the demographic paradigm of ecology is strongly developed and consistent. Its premises and logic extend into current models of population genetics, biogeography, palaeontology, evolutionary theory and conservation biology. Nevertheless, many phenomena contradict the premises of the demographic paradigm; these contradictions cannot be accommodated within its theoretical framework without major disruptions in logic ensuing. Such phenomena can, in contrast, be understood in terms of the autecological paradigm. Because the status and strengths of the autecological paradigm are generally unrecognised and because autecology is frequently misrepresented in the literature, we redefine its premises and clarify its structure and aims as an aid to its future development. (shrink)

Ecological theory is built upon assumptions about the fundamental nature of organism-environment interactions. We argue that two mutually exclusive sets of such assumptions are available and that they have given rise to alternative approaches to studying ecology. The fundamentally different premises of these approaches render them irreconcilable with one another. In this paper, we present the first logical formalisation of these two paradigms.The more widely-accepted approach - which we label the demographic paradigm - includes both population ecology and community ecology (...) (synecology). Demographic ecology assumes that the environment is relatively stable and that biotic processes, governed predominantly by resource availability, are the most important of ecological and evolutionary influences. Moreover, ecological processes are assumed to translate into directional selection pressures that drive significant evolutionary change on a local scale through the process of optimisation. (shrink)

This paper reviews and extends ideas of eukaryotization by endosymbiosis. These ideas are put within an historical context of processes that may have led up to eukaryotization and those that seem to have resulted from this process. Our starting point for considering the emergence and development of life as an organized system of chemical reactions should in the first place be in accordance with thermodynamic principles and hence should, as far as possible, be derived from these principles. One trend to (...) be observed is the ever-increasing complexity resulting in several layers of compartmentalization of the reaction system, either spatial (of which the eukaryotic cell is an example), or functional (as in the gradually deepening distinction between metabolic, enzymatic and information-storing functions within the cell). One of the causes of this complexification of living systems will have been the changes in environmental conditions, particularly the geochemical impoverishment of the biosphere during geological history, partly brought about by living systems themselves, and partly by the trend towards increasing efficiency and specificity of the reactions that occur. (shrink)

This paper analyses the broad methodological structure of population-biological theorising. In it, I show that the distinction between initial exploratory, hypothesis-generating research and the subsequent process-reconstructing, hypothesis-testing type of research is not being made. Rather, the hypotheses generated in population biology are elaborated in such detail that students confound the initial research phase with the subsequent hypotheses-testing phase of research. In this context, I therefore analyse some testing procedures within the exploration phase and show that, as an extreme form of (...) confusion, statistical null-models are mistakenly given the status of causal population-biological theory. (shrink)

This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According to the first approach, life would have begun with—often organic—compounds. After having developed to a certain level of complexity and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast, the second, physical type of (...) approach has life developing within tiny compartments from the beginning. It emphasises the importance of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary, “life” would not have begun, nor have been maintained; this boundary—and the complex cell membrane that evolved from it—forms the essence of life. (shrink)

This paper distinguishes four recognisably different geographical processes in principle causing species to die out. One of these processes, the one we dub “range eclipse”, holds that one range expands at the expense of another one, thereby usurping it. Channell and Lomolino (2000a, Journal of Biogeography 27: 169–179; 2000b, Nature 403: 84–87; see also Lomolino and Channell, 1995, Journal of Mammalogy 76: 335–347) measured the course of this process in terms of the proportion of the total range remaining in its (...) original centre, thereby essentially assuming a homogeneous distribution of animals over the range. However, part of their measure seems mistaken. By giving a general, analytical formulation of eclipsing ranges, we estimate the exact course of this process. Also, our formulation does not partition a range into two spatially equal parts, its core and its edge, but it assumes continuity. For applying this model to data on the time evolution of species, individual time series should be available for each of them. For practical purposes we give an alternative way of plotting and interpreting such time series. Our approach, being more sensitive than Channell and Lomolino’s, gives a less optimistic indication of range eclipses than theirs once these have started. (shrink)