Q and A: some common questions
What is thermodynamics?
Thermodynamics is the study of energy relationships. Thermo- means heat and -dynamics means motion. Thermodynamics is central to understand how our universe works, particularly in terms of change and direction of change.
What are the first and second laws of thermodynamics?
The first law states that energy can neither be created nor destroyed. Energy can only change from one form to another. Or, you can only break even. Einstein explained how mass can be converted to energy. The sun uses this trick to release huge amounts of energy into space, a fraction of which hits the earth.
The second law states that the universe is becoming increasingly chaotic and diffuse, and that any energy transition within the universe must produce entropy. Gradually, the universe becomes more disorganized as it ages. Eventually the universe will reach a static equilibrium where no work is possible as it approaches absolute zero temperature, a point called heat death.
What is the maximum entropy production principle (MEPP)?
Systems (like the biosphere) through which energy flows tend towards a state of maximum energy use, where energy is converted from useful to less useful forms, reducing potential energy available for work, meaning that that entropy increases. Lifeforms have been called dissipating structures, and life can be viewed as a producer of waste energy, increasing the chaos of the universe. The rate of entropy production follows a logistic curve, approaching an asymptote or ceiling, Smax, the state of maximum entropy production possible for a given system. At any level of organization this ceiling will be determined by limitations within that level and the other levels within the overall system. Too much entropy production, and the surroundings, where this chaos goes, becomes destabilized. Thus there is a limit to complexity as well as entropy production, since increasing complexity requires increasing energy flow to maintain it. That is why ecological succession comes to a halt eventually at its maximum level of complexity.
Surely evolution and life defy the Second law of thermodynamics?
Although the universe is heading towards absolute chaos and perfect disorder, at present, the sun is only about half way through its fuel, and so is releasing energy. When this arrives at the earth’s surface, some of it is used to build complexity. This construction releases entropy (since every energy transformation step releases entropy), and more entropy is released in maintaining this structure. Thus complexity is in agreement with the second law of thermodynamics, provided there is a source of energy available. Complexity will continue to increase up to a level where it can increase no further, limited by constraints from the system, just as there are limits on how high we can build a skyscraper, or how fast we can travel. Altering the available energy will change this limit. Thus a mass extinction which dramatically reduces the free energy available will have a devastating impact on life on earth, and evolution will begin again from a much simplified foundation, rebuilding as energy flow is restored.
How can thermodynamics explain evolution?
The drive towards increased chaos in the universe, combined with the availability of light from the sun allows life to emerge and evolve in order to facilitate increased chaos. This is driven by the second law of thermodynamics and the maximum entropy production principle. Thermodynamics acts as a huge signpost, telling systems in which direction to head and at what speed. Thus life, as one of a number of entities that dissipate free energy and produce increasing disorder, will emerge and evolve under the laws of thermodynamics, diffusing to fill available energetic space. On earth, this is done by increasing chaos within the genetic material (through random mutations), increasing diffusion of protein shapes within their energetic context, increasing exploration of ecospace at the organism level, increasing populations and increasing complexity in ecological succession. All of these changes occur within the limits of the maximum entropy production principle. The outcomes are modelled in my paper, as are the implications for many of the questions in evolution relating to tempo, fitness, competition and biosphere architecture.
What’s wrong with natural selection and the selfish gene?
Natural selection was a beautiful theory of evolution developed in the mid 19th century by the brilliant Charles Darwin. But science moves forward by challenging theories as new insights are made. Natural selection began as an analogy, based on artificial selection (pig-breeding and the like). It borrowed from the Book of Revelation in the Bible (the horsemen of the Apocalypse), and the death of Darwin’s daughter as a child drove him to crystalize his thoughts. However we now have much more information, much of which comes into conflict with this theory. Competition is now not considered as significant in evolution. Selection fails completely to predict the response of the fossil record to mass extinctions. The modern equivalent, the selfish gene, fails completely to explain succession, a central issue in understanding evolution. Furthermore, the gene as the only unit of selection fails to account for emergent properties, system biology considerations and the failure of genetic fitness to account for recent discoveries relating to reproductive success in “unfit” members of populations, such as guppies and crickets. There are just too many holes, and given that thermodynamics fills all of these holes, my paper delivers a working theory that marries ecology, evolution and molecular biology, something that the selfish gene fails to do (Dawkins attempt at this, the extended phenotype, makes painful reading for any ecologist). Finally, the model developed from the theory predicts the fossil record of diversity over the past 500 million years to an accuracy of 99.9% certainty.
Why are mass extinctions so important in this theory?
The figure here demonstrates the problem. The fossil record stands to challenge Darwinian thinking to its core. Under conditions of selection and competition, evolution slows down, while in the absence of competition and selection, evolution speeds up. This is the opposite of what Darwinian theory predicts. This is a significant problem.
What about those finches?
The Galapagos Islands have long been considered as the cathedral of Darwinian evolution, and the finches represent the high priests. Yet what is the true story relating to these finches? A small group of a single species, perhaps 30 individuals, were most likely blown across the Pacific Ocean around 2.8 million years ago, landing on this distant archipelago. Here, they speciated. So far, so good. The point is that this speciation occurred relatively quickly and then stopped. Once the formerly empty market place filled up, natural selection and competition ensured there was no further evolution. This follows the same trend as post-extinction recovery. The islands were obviously highly suited to the single species of finch that arrived, otherwise they would have died. Thus there was no selection pressure, just lots of space and resource. The finches then diffused, in terms of form and function, driven by increasing entropy within their codes (mutations), and allowing new forms and functions to emerge as diversity increased to Dmax, which represents the maximum entropy possible within the constraints. At this point, selection pressure built and evolution slowed. This is the opposite of what Darwinian theory would predict.
What do you mean by the empty market place and the crowded back alleys?
The empty market place represents space where life can exist, but doesn’t. Life can then diffuse into this space when the opportunity arises. Imagine two sealed rooms with an airtight door between them. If we spray perfume in one, the perfume will defuse to fill the room. The room now becomes a crowded back alley. If we now open the door, the perfume will diffuse into the second room. This process of diffusion is driven by the second law of thermodynamics. In much the same way, as mutations build in the genetic material of a species, the form and function of that species expand in future generations, diffusing into ecospace, and leading to new species. Once the room is filled with species, a dynamic equilibrium ensues, wherein no further space can be filled unless another door is open to another room, or a pump removes some of the perfume from a part of the room. If this happens, the second law predicts that the diffusive process will act to fill the newly available space.
Is earth an open system or a closed system, and does it matter?
Earth is an open system. This is important because it means it releases entropy to the rest of the universe. Thus although complexity may increase on this planet, it will be at a cost, with disorganization increasing beyond the planet, as demanded by the second law.
Why didn’t somebody think of this before you?
Ideas related to the importance of thermodynamics for evolution have been around for over one hundred years. This is why I spent so long in the introduction of the paper sketching out this history. What is evident from this is that many physicists were unwilling to challenge biological theory, as it was outwith their field. Thus they sought to pin their own thinking onto the Darwinian framework. As a biologist and biophysicist (my first paper was on photosynthetic physics of seaweeds), I approached the issue from the opposite direction. Part of my insight was also due to staffing shortages within the Biological Sciences Institute at the University of Dundee where I worked. Initially appointed as a plant community ecologist (though having specialized in plant developmental biology and ecophysiology in my PhD), I arrived in the Department at a time when many staff were leaving, having been headhunted by other universities in an attempt to gain an advantage in the new Research Assessment Exercise. Thus I was asked to lecture on everything from microbiology to biochemistry, evolution to succession and zoology to animal behaviour. I felt I could only do this if I wrote papers in these areas, so set about publishing in each of these disciplines. This resulted in me having a very broad and fairly deep knowledge across the subject of biology, allowing me to observe patterns and synthesise ideas that others would be unable to do, given the usual narrow focus of most academics. My publication list was described as “scattergun” by the Principal of the University, but I realized by then that it was leading somewhere.
Another irony is that as biochemistry began to dominate, no further recruitment into ecology was made. Thus I was the last principal investigator appointed as an ecologist. The first appointment had been one hundred years earlier, in the shape of Patrick Geddes. When he left, he stated that "Each of the various specialists remains too closely concentrated upon his single specialism, too little awake to those of the others. Each sees clearly and seizes firmly upon one petal of the six-lobed flower of life and tears it apart from the whole". It is ironic that I became a generalist as a result of the focus on narrow research, meaning that I had to take the teaching from the key researchers to allow them to compete in the government assessment exercise. This last ecologist fulfilled the first ecologist’s vision of generalism, but not in the way that Geddes may have predicted.
Who cares? Why is it important to me?
We explore this in the section Implications: the birth of a new worldview.
What is thermodynamics?
Thermodynamics is the study of energy relationships. Thermo- means heat and -dynamics means motion. Thermodynamics is central to understand how our universe works, particularly in terms of change and direction of change.
What are the first and second laws of thermodynamics?
The first law states that energy can neither be created nor destroyed. Energy can only change from one form to another. Or, you can only break even. Einstein explained how mass can be converted to energy. The sun uses this trick to release huge amounts of energy into space, a fraction of which hits the earth.
The second law states that the universe is becoming increasingly chaotic and diffuse, and that any energy transition within the universe must produce entropy. Gradually, the universe becomes more disorganized as it ages. Eventually the universe will reach a static equilibrium where no work is possible as it approaches absolute zero temperature, a point called heat death.
What is the maximum entropy production principle (MEPP)?
Systems (like the biosphere) through which energy flows tend towards a state of maximum energy use, where energy is converted from useful to less useful forms, reducing potential energy available for work, meaning that that entropy increases. Lifeforms have been called dissipating structures, and life can be viewed as a producer of waste energy, increasing the chaos of the universe. The rate of entropy production follows a logistic curve, approaching an asymptote or ceiling, Smax, the state of maximum entropy production possible for a given system. At any level of organization this ceiling will be determined by limitations within that level and the other levels within the overall system. Too much entropy production, and the surroundings, where this chaos goes, becomes destabilized. Thus there is a limit to complexity as well as entropy production, since increasing complexity requires increasing energy flow to maintain it. That is why ecological succession comes to a halt eventually at its maximum level of complexity.
Surely evolution and life defy the Second law of thermodynamics?
Although the universe is heading towards absolute chaos and perfect disorder, at present, the sun is only about half way through its fuel, and so is releasing energy. When this arrives at the earth’s surface, some of it is used to build complexity. This construction releases entropy (since every energy transformation step releases entropy), and more entropy is released in maintaining this structure. Thus complexity is in agreement with the second law of thermodynamics, provided there is a source of energy available. Complexity will continue to increase up to a level where it can increase no further, limited by constraints from the system, just as there are limits on how high we can build a skyscraper, or how fast we can travel. Altering the available energy will change this limit. Thus a mass extinction which dramatically reduces the free energy available will have a devastating impact on life on earth, and evolution will begin again from a much simplified foundation, rebuilding as energy flow is restored.
How can thermodynamics explain evolution?
The drive towards increased chaos in the universe, combined with the availability of light from the sun allows life to emerge and evolve in order to facilitate increased chaos. This is driven by the second law of thermodynamics and the maximum entropy production principle. Thermodynamics acts as a huge signpost, telling systems in which direction to head and at what speed. Thus life, as one of a number of entities that dissipate free energy and produce increasing disorder, will emerge and evolve under the laws of thermodynamics, diffusing to fill available energetic space. On earth, this is done by increasing chaos within the genetic material (through random mutations), increasing diffusion of protein shapes within their energetic context, increasing exploration of ecospace at the organism level, increasing populations and increasing complexity in ecological succession. All of these changes occur within the limits of the maximum entropy production principle. The outcomes are modelled in my paper, as are the implications for many of the questions in evolution relating to tempo, fitness, competition and biosphere architecture.
What’s wrong with natural selection and the selfish gene?
Natural selection was a beautiful theory of evolution developed in the mid 19th century by the brilliant Charles Darwin. But science moves forward by challenging theories as new insights are made. Natural selection began as an analogy, based on artificial selection (pig-breeding and the like). It borrowed from the Book of Revelation in the Bible (the horsemen of the Apocalypse), and the death of Darwin’s daughter as a child drove him to crystalize his thoughts. However we now have much more information, much of which comes into conflict with this theory. Competition is now not considered as significant in evolution. Selection fails completely to predict the response of the fossil record to mass extinctions. The modern equivalent, the selfish gene, fails completely to explain succession, a central issue in understanding evolution. Furthermore, the gene as the only unit of selection fails to account for emergent properties, system biology considerations and the failure of genetic fitness to account for recent discoveries relating to reproductive success in “unfit” members of populations, such as guppies and crickets. There are just too many holes, and given that thermodynamics fills all of these holes, my paper delivers a working theory that marries ecology, evolution and molecular biology, something that the selfish gene fails to do (Dawkins attempt at this, the extended phenotype, makes painful reading for any ecologist). Finally, the model developed from the theory predicts the fossil record of diversity over the past 500 million years to an accuracy of 99.9% certainty.
Why are mass extinctions so important in this theory?
The figure here demonstrates the problem. The fossil record stands to challenge Darwinian thinking to its core. Under conditions of selection and competition, evolution slows down, while in the absence of competition and selection, evolution speeds up. This is the opposite of what Darwinian theory predicts. This is a significant problem.
What about those finches?
The Galapagos Islands have long been considered as the cathedral of Darwinian evolution, and the finches represent the high priests. Yet what is the true story relating to these finches? A small group of a single species, perhaps 30 individuals, were most likely blown across the Pacific Ocean around 2.8 million years ago, landing on this distant archipelago. Here, they speciated. So far, so good. The point is that this speciation occurred relatively quickly and then stopped. Once the formerly empty market place filled up, natural selection and competition ensured there was no further evolution. This follows the same trend as post-extinction recovery. The islands were obviously highly suited to the single species of finch that arrived, otherwise they would have died. Thus there was no selection pressure, just lots of space and resource. The finches then diffused, in terms of form and function, driven by increasing entropy within their codes (mutations), and allowing new forms and functions to emerge as diversity increased to Dmax, which represents the maximum entropy possible within the constraints. At this point, selection pressure built and evolution slowed. This is the opposite of what Darwinian theory would predict.
What do you mean by the empty market place and the crowded back alleys?
The empty market place represents space where life can exist, but doesn’t. Life can then diffuse into this space when the opportunity arises. Imagine two sealed rooms with an airtight door between them. If we spray perfume in one, the perfume will defuse to fill the room. The room now becomes a crowded back alley. If we now open the door, the perfume will diffuse into the second room. This process of diffusion is driven by the second law of thermodynamics. In much the same way, as mutations build in the genetic material of a species, the form and function of that species expand in future generations, diffusing into ecospace, and leading to new species. Once the room is filled with species, a dynamic equilibrium ensues, wherein no further space can be filled unless another door is open to another room, or a pump removes some of the perfume from a part of the room. If this happens, the second law predicts that the diffusive process will act to fill the newly available space.
Is earth an open system or a closed system, and does it matter?
Earth is an open system. This is important because it means it releases entropy to the rest of the universe. Thus although complexity may increase on this planet, it will be at a cost, with disorganization increasing beyond the planet, as demanded by the second law.
Why didn’t somebody think of this before you?
Ideas related to the importance of thermodynamics for evolution have been around for over one hundred years. This is why I spent so long in the introduction of the paper sketching out this history. What is evident from this is that many physicists were unwilling to challenge biological theory, as it was outwith their field. Thus they sought to pin their own thinking onto the Darwinian framework. As a biologist and biophysicist (my first paper was on photosynthetic physics of seaweeds), I approached the issue from the opposite direction. Part of my insight was also due to staffing shortages within the Biological Sciences Institute at the University of Dundee where I worked. Initially appointed as a plant community ecologist (though having specialized in plant developmental biology and ecophysiology in my PhD), I arrived in the Department at a time when many staff were leaving, having been headhunted by other universities in an attempt to gain an advantage in the new Research Assessment Exercise. Thus I was asked to lecture on everything from microbiology to biochemistry, evolution to succession and zoology to animal behaviour. I felt I could only do this if I wrote papers in these areas, so set about publishing in each of these disciplines. This resulted in me having a very broad and fairly deep knowledge across the subject of biology, allowing me to observe patterns and synthesise ideas that others would be unable to do, given the usual narrow focus of most academics. My publication list was described as “scattergun” by the Principal of the University, but I realized by then that it was leading somewhere.
Another irony is that as biochemistry began to dominate, no further recruitment into ecology was made. Thus I was the last principal investigator appointed as an ecologist. The first appointment had been one hundred years earlier, in the shape of Patrick Geddes. When he left, he stated that "Each of the various specialists remains too closely concentrated upon his single specialism, too little awake to those of the others. Each sees clearly and seizes firmly upon one petal of the six-lobed flower of life and tears it apart from the whole". It is ironic that I became a generalist as a result of the focus on narrow research, meaning that I had to take the teaching from the key researchers to allow them to compete in the government assessment exercise. This last ecologist fulfilled the first ecologist’s vision of generalism, but not in the way that Geddes may have predicted.
Who cares? Why is it important to me?
We explore this in the section Implications: the birth of a new worldview.