Glossary: explanation of some of the
key terms
Biosphere: the sum of all life on the planet.
Closed system: a thermodynamic term, referring to a system that is self-contained with no transfer of mass nor energy into or out of it. The Universe represents a closed system, while Earth is an open system, with both mass and energy transferring across its boundaries. Many schools of sustainability incorrectly reference earth as a closed system, leading to such fantasies as a circular economy.
Complex systems theory: examines how the interactions of sub-systems give rise to system-level properties.
Diffusion: the movement of material down a concentration gradient or the spreading out of material. Entropy is a measure of the spreading process, and diffusion is a direct outcome of the second law of thermodynamics, which determines that energy spreads out in the universe, eventually leading to a state of “perfect chaos” where temperature drops to absolute zero and the universe is in equilibrium. This is referred to as the heat death of the universe, a point from which there may be no recovery. Diffusion occurs throughout the universe, exhibited on earth in many situations. It is a spontaneous outcome, and requires energy to reverse it. Diffusion represents a classic proof of thermodynamics in action and is central to many processes on earth. The thermodynamic theory of evolution posits that it is also central to biological evolution.
Dynamic equilibrium: a school of thought that recognizes that no subsystem can reach a climax or static state, given the continued change of the overall system (the universe) and the ongoing interactions with other subsystems. Change is constant and results from feedback. An equilibrium represents a hypothetical state around which real sub-systems oscillate. However the Universe may ultimately reach a static equilibrium at heath death.
Ecosystem: the abiotic and biotic environment of an organism, consisting of all of the interactions and representing a self-organizing unit, formed from populations of organisms and being part of a biome.
Emergence: outcomes which are different from the sum of the parts of a sub-system or system, such as imagination, life and ecological succession.
Entropy: the unavailability of a system's thermal energy for conversion into mechanical work, also defined as diffusion or, more loosely, disorder. The second law of thermodynamics states that the entropy within a closed system (the universe) will increase until equilibrium is achieved.
First law of thermodynamics: energy can neither be created nor destroyed, or, you can only break even.
Flow structures: structures such as living organisms that can exist thermodynamically only because energy is continuously flowing through them. Also referred to as dissipating structures, because the energy is converted to a less useful form by passing through these structures. Concept developed by Ilya Prigogine.
Mass extinction: the extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt. There have been five such events in the history of life on earth, and some suggest that we are in the midst of a sixth event, caused by humans.
Maximum entropy production principle (MEPP): non-equilibrium thermodynamic systems are organized in steady state such that the rate of entropy production is maximized.
Modern evolutionary synthesis: linking Darwinism to genetics, the synthesis sets out the gene as the unit of selection, and the phenotype as the outcome of the genes. Increasing frequencies of genes in populations represents genetic fitness.
Natural selection: the process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated. A consequence is a significant reduction of diversity, the very quality needed for diversification, and a reliance on competition, which is now viewed as unimportant in diversification. Replacement rather than displacement is thought now to be the most important process in evolution.
Neo-Darwinism: Darwinian evolution embracing the modern evolutionary synthesis and focused on the gene as the unit of selection and as selfish. It fails to explain ecological succession, where genes act in such a way as to eradicate themselves from later stages of succession.
Post-selectionism: a set of evolutionary theories that do not hold that natural selection is a useful way of understanding biological evolution. The gene is not viewed as the unit of selection, and evolution is not understood within a reductionist framework, but a holistic one. Alternative models include thermodynamic diffusion.
Reductionism: the philosophy that more complex levels are merely outcomes of the building blocks at the most basic level. Thus we can understand more complex levels by studying greatly simplified levels. Furthermore, we can alter more complex levels by altering more fundamental levels, e.g. in genetic modification of organisms, or introducing cane toads to Australia.
Second Law of Thermodynamics: in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state. Or, you can’t even break even, or, there is no such thing as perpetual motion.
Selfish gene: the gene-centred view of evolution, which holds that evolution is best viewed as acting on genes and that selection at the level of organisms or populations almost never overrides selection based on genes.
Succession: the process of ecosystem development, from bare soil or sand to forest in the example of lowland succession.
System biology: the study of biology as a system with sub-systems which interact, producing emergent properties.
Transductionism: the name given to the underlying philosophy of the thermodynamic theory. Transductionism refers to the idea that there is no single level of change that then impacts on the other levels, but rather every level interacts with the driver of change separately, while interacting with the other levels. This is very different from reductionism (where a single level of selection, the gene, determines all else, the extended phenotype, and equally different from Holism, where a Gaian concept of the super planet operates and results in a top down control. Here the flow of energy through each of the levels of organization leads to the movement of each of these levels towards a functional maximum entropic production, while compromised and influenced by each of the levels surrounding any particular level. Thus the maximum entropic production for a given level is that which allows the overall system to maximise its entropic production. Exceeding this energetic transformation at any given level will lead to collapse or attenuation.
Trophodynamics: The study of energy transfer through the biosphere. Includes analysis of food webs and the importance of energy flow.
Biosphere: the sum of all life on the planet.
Closed system: a thermodynamic term, referring to a system that is self-contained with no transfer of mass nor energy into or out of it. The Universe represents a closed system, while Earth is an open system, with both mass and energy transferring across its boundaries. Many schools of sustainability incorrectly reference earth as a closed system, leading to such fantasies as a circular economy.
Complex systems theory: examines how the interactions of sub-systems give rise to system-level properties.
Diffusion: the movement of material down a concentration gradient or the spreading out of material. Entropy is a measure of the spreading process, and diffusion is a direct outcome of the second law of thermodynamics, which determines that energy spreads out in the universe, eventually leading to a state of “perfect chaos” where temperature drops to absolute zero and the universe is in equilibrium. This is referred to as the heat death of the universe, a point from which there may be no recovery. Diffusion occurs throughout the universe, exhibited on earth in many situations. It is a spontaneous outcome, and requires energy to reverse it. Diffusion represents a classic proof of thermodynamics in action and is central to many processes on earth. The thermodynamic theory of evolution posits that it is also central to biological evolution.
Dynamic equilibrium: a school of thought that recognizes that no subsystem can reach a climax or static state, given the continued change of the overall system (the universe) and the ongoing interactions with other subsystems. Change is constant and results from feedback. An equilibrium represents a hypothetical state around which real sub-systems oscillate. However the Universe may ultimately reach a static equilibrium at heath death.
Ecosystem: the abiotic and biotic environment of an organism, consisting of all of the interactions and representing a self-organizing unit, formed from populations of organisms and being part of a biome.
Emergence: outcomes which are different from the sum of the parts of a sub-system or system, such as imagination, life and ecological succession.
Entropy: the unavailability of a system's thermal energy for conversion into mechanical work, also defined as diffusion or, more loosely, disorder. The second law of thermodynamics states that the entropy within a closed system (the universe) will increase until equilibrium is achieved.
First law of thermodynamics: energy can neither be created nor destroyed, or, you can only break even.
Flow structures: structures such as living organisms that can exist thermodynamically only because energy is continuously flowing through them. Also referred to as dissipating structures, because the energy is converted to a less useful form by passing through these structures. Concept developed by Ilya Prigogine.
Mass extinction: the extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt. There have been five such events in the history of life on earth, and some suggest that we are in the midst of a sixth event, caused by humans.
Maximum entropy production principle (MEPP): non-equilibrium thermodynamic systems are organized in steady state such that the rate of entropy production is maximized.
Modern evolutionary synthesis: linking Darwinism to genetics, the synthesis sets out the gene as the unit of selection, and the phenotype as the outcome of the genes. Increasing frequencies of genes in populations represents genetic fitness.
Natural selection: the process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated. A consequence is a significant reduction of diversity, the very quality needed for diversification, and a reliance on competition, which is now viewed as unimportant in diversification. Replacement rather than displacement is thought now to be the most important process in evolution.
Neo-Darwinism: Darwinian evolution embracing the modern evolutionary synthesis and focused on the gene as the unit of selection and as selfish. It fails to explain ecological succession, where genes act in such a way as to eradicate themselves from later stages of succession.
Post-selectionism: a set of evolutionary theories that do not hold that natural selection is a useful way of understanding biological evolution. The gene is not viewed as the unit of selection, and evolution is not understood within a reductionist framework, but a holistic one. Alternative models include thermodynamic diffusion.
Reductionism: the philosophy that more complex levels are merely outcomes of the building blocks at the most basic level. Thus we can understand more complex levels by studying greatly simplified levels. Furthermore, we can alter more complex levels by altering more fundamental levels, e.g. in genetic modification of organisms, or introducing cane toads to Australia.
Second Law of Thermodynamics: in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state. Or, you can’t even break even, or, there is no such thing as perpetual motion.
Selfish gene: the gene-centred view of evolution, which holds that evolution is best viewed as acting on genes and that selection at the level of organisms or populations almost never overrides selection based on genes.
Succession: the process of ecosystem development, from bare soil or sand to forest in the example of lowland succession.
System biology: the study of biology as a system with sub-systems which interact, producing emergent properties.
Transductionism: the name given to the underlying philosophy of the thermodynamic theory. Transductionism refers to the idea that there is no single level of change that then impacts on the other levels, but rather every level interacts with the driver of change separately, while interacting with the other levels. This is very different from reductionism (where a single level of selection, the gene, determines all else, the extended phenotype, and equally different from Holism, where a Gaian concept of the super planet operates and results in a top down control. Here the flow of energy through each of the levels of organization leads to the movement of each of these levels towards a functional maximum entropic production, while compromised and influenced by each of the levels surrounding any particular level. Thus the maximum entropic production for a given level is that which allows the overall system to maximise its entropic production. Exceeding this energetic transformation at any given level will lead to collapse or attenuation.
Trophodynamics: The study of energy transfer through the biosphere. Includes analysis of food webs and the importance of energy flow.