What is life?

1. What is life?

2. The main property of life: its complexity It is unprecedented in the inanimate world. Because of their fantastic complexity, living systems never arise spontaneously in whatever fluxes of external energy. They only come to existence by means of copying of some other living systems. In contrast, ordered processes in the inanimate nature arise spontaneously in external energy fluxes.

3. Decay of ordered states in nature All complex processes in nature undergo spontaneous decay. They arise from an initial ordered state which decays to a less ordered state. On Earth most ordered processes arise because of each solar photon coming to the Earth decays into twenty thermal photons leaving the Earth to space. The increase in disorder (entropy) is associated with the increasing number of particles (photons). Complexity of the process is determined NOT BY THE AVAILABLE ENERGY FLUX but by the particular routes of solar photon transformation to thermal photons (decay channels). Life uses an ultra-complex set of such channels that have no match in the inanimate world.

4. Living beings can only arise as copies of other living beings. Ordered inanimate patterns arise spontaneously: e.g., “cloud streets” (ordered cloud patterns) are caused by atmospheric motions.

5. Frequency of occurrence and duration • Frequency of occurrence FO of any processes is inversely proportional to their complexity. • Simple processes are common, highly organized processes are rare. • All processes can be characterized by the beginning and the end (duration time) TD. • Commonly, for ordered processes TD << 1/FO.

6. Life is a unique process with FO0 and TD. • It never arises spontaneously. • Its duration time (~4 billion yr) is comparable to that of the Universe itself.

7. Challenge: how to preventspontaneousdecay of the genetic program of life? If orderliness of living beings is not determined by the external energy fluxes, how is it maintained? How has it been possible for life to retain its orderliness and to persist for about four billion years, i.e. on a time-scale compatible to the age of the Universe? Life universal DNA error rate ~10-9 per base pair per act of copying

8. What information is needed for life to fight with decay? • Life exists in the form of discrete objects – living beings – that have a finite size. • Every kind (species) of living beings exist in the form of a set of many similar objects (population). No species exists in the form of one individual. Individuals within a population compete with each other. • An inherent genetically encoded property of all living beings is the tendency to occupy all available areas (expansion).

9. Competitive interaction as a unique means of sustaining orderliness Note the difference between “removal of the non-fit” and the Darwinian “survival of the fittest”. Without indicating what the “the fittest” is, “survival of the fittest” is a tautology. “Non-fit” is an object whose genetic program deviates from the normal one by a certain amount that exceeds the sensitivity of competitive interaction.

10. Any level of organization of living objects is maintained by competitive interaction Any type of internal correlation of living objects is maintained by competitive interaction at the next higher level. For example, correlation of cells within a multicellular body is maintained by competition in a population of multicellular living beings. The highest level of correlation is the local ecological community. In forest ecosystems it is represented by individual trees and the associated local plants, animals, bacteria and fungi. A single globally correlated organism (Gaia) would not be able to persist.

11. The main challenge for life: Life can only exist in a narrow interval of environmental conditions This challenge is a direct consequence of life’s complexity: the higher the orderliness of a particular phenomenon, the rarer the environmental conditions where it can occur.

12. Life-compatible environment: • Water in the liquid phase • Particular concentrations of life-important chemical substances • … Example: Redfield ratio in the ocean

13. The problem: spontaneous degradation of life-compatible environment Atmospheric carbon as an example In the absence of biotic control, atmospheric concentration of carbon would have increased by a factor of ten thousand in a billion of years at the expense of carbon degassing from the Earth’s interior. Life has been depositing the excessive carbon in the form of inactive organic compounds at a rate equal to that of carbon degassing, to keep the atmospheric concentration of carbon relatively stable. Stores (Gt C, rectangles) and fluxes (Gt C/year, arrows) of organc (dark) and inorganic (white) carbon to and from the biosphere during the Phanerozoi (the last 6 x 108 years).

14. The problem: spontaneous degradation of life-compatible environment Soil organic carbon as an example Disturbed ecosystems are unable to sustain organic carbon in soil. On exploited lands soils degrade completely on a time scale from a few years to 200-300 years. Tropical soils have smaller carbon stores and are exceptionally vulnerable. Organic carbon depletion time versus erosion rate in ecosystems of varying degree of disturbance. Data of Quinton et al. 2010 Nature Geoscience 3: 311. Total global store of soil carbon ~2x103 Gt C.

15. Life and modern science: No comprehensive approach <=> no understanding No one scientific discipline takes the responsibility for the inconsistencies that arise when data from different scientificfields are considered simultaneously. Theoretical physics is a field of science which primarily seeks to build an comprehensive and coherent picture of the studied phenomena, to formulate a view that is free from internal contradictions.

16. Life and modern science: Evolutionary Biology Environment that is fit for life degrades on a much shorter time scale than the evolutionary time scale Tev ~ 3x106 years (mean time of species existence), Tev >> Tdegr. Evolutionary biology (the paradigms of survival of the fittest and adaptation) completely ignores this environmental problem and thus cannot explain why life persists. Species discreteness and punctuated speciation remain unexplained.

17. Life and modern science: Ecology Ecology is dominated by studies of large animals (predator-prey models) and, historically, is mostly fed by data from disturbed or degrading ecosystems. The majority of ecologists can be compared to doctors who have never seen a healthy human being and consider dying or seriously ill people to be the norm. One of the misconceptions: the idea of “nutrient limitation” (Liebech principle) as the basis of natural ecosystem functioning.

18. Life and modern science: Daisyworld (Gaia) studies This is a very small sector in life studies. In contrast to evolutionary biologists, Gaia modelers aim to explain environmental stability. But their main challenge is that they cannot explain how the level of organization necessary to stabilize global environment can be guarded against genetic degradation? That is, against the mutation of “regulating” daises to “non-regulating” ones.

19. Life and modern science: Climate science Climate science is dominated by physical models which would be built in basically the same way if the Earth was lifeless. The unknown regulatory programs of ecosystems are ignored. Impact of life is taken into account in the form of empirical parameterizations which lack predicative power. Example: parameterization of evapotranspiration

20. Biotic regulation of the environment Because of its high complexity, life can only exist in a narrow interval of environmental conditions. Spontaneous persistence of such conditions in the inanimate world is im-probable. Hence, life must contain information on how to maintain such conditions. To perform environmental regulation, life must be highly-ordered and complex.

21. Life is a process that is complex enough to create and maintain conditions necessary for its own perpetuation.

22. Globally and locally regulated biogens Locally regulated biogens: P+ \ Fout ~ 1 Biological productivity exceeds the abiotic fluxes. Example: soil phosphorus Globally regulated biogens:  <P+ /Fout <<1 Biological productivity is smaller than the abiotic fluxes of biogens, but their ratio exceeds biotic sensitivity  ~ 10-3. Example: atmospheric CO2. Regulation of global environmental parameters by local ecological communities

23. Condensation over local ecological communities in Papua New Guinea pristine forest Image credit: Rocky Roe & UPNG Remote Sensing Centre

24. Who is the fittest? How to couple competitiveness and biotic regulation? Competitiveness of a local ecological community depends on two things: (1) its environment and (2) its genetic program. If, because of spontaneous genetic decay, the community loses its ability to regulate the environment (the program is partially eroded), then its favorable environment begins to deteriorate. The condition of genetic stability is that the decay individual loses competitiveness because of environmental degradation BEFORE it has outcompeted (replaced) all the normal ecological communities.

25. The danger of abundance (visualization) Normal local ecological communities and decay ecological community. Normal communities keeps the environment favorable for life. Decay community does not, but is able to suppress normal communities. Texp – time by which the gangsters kill the entire population. Tdegr – time by which the environment becomes unsuitable for gangsters. Large biomass stores increase Tdegr.

26. Quantitative criteria of life stability Texp >> Tdegr Texp – time of global expansion of a decay ecological community Tdegr – time of degradation of its local environment Tdegr ~  M/F (turnover time) M is the store of a local biogen, F is the environmental flux changing this store in the absence of biotic regulation. Stability is enhanced by decreasing turnover time of life-important biogens. This is achieved by elevating the rates of biological synthesis P+ and decomposition P- (i.e., by increasing F) and by decreasing the available stores of biogens M (decreasing abundance).

27. Biomass, productivity and turnover times in the biosphere

28. Short and long turnover times  M/P+ Epilithic lichens (alga + fungus) Boreal forest Small biomass M, high productivity P+ => Short turnover time Large biomass M, same productivity P+ => Long turnover time

29. The danger of abundance What is the main difference between forest ecosystem and oceanic ecosystem? Terrestrial forest ecosystems contain ten thousand times larger amount of live biomass M per unit area than do oceanic ecosystems. Net primary productivity (per unit area) is only ten times larger in the forest than in the open ocean. This elevates time Tdegr ~ M/P+ in forest ecosystems and make them intrinsically unstable compared to the low biomass oceanic ecosystems.

30. Why do large animals potentially undermine life stability? 1. The basis of life on Earth is solar radiation. It is represented by massless particles – photons. Lacking mass, photons cannot accumulate on the Earth surface. Therefore, plants that live on the energy of solar photons, do not need to move. They form a continuous immobile cover on land.

31. 2. Universal mean rate of energy consumption per unit live mass across life Irrespective of their evolutionary rank and genome size, the various life forms consume between 1 and 10 Watts per kilogram of live mass.

32. 3. Growth of energy consumption per unit area with increasing body size Largeorganisms consume more energy per unit ground surface area per unit time than plants can offer (P+max ~ 2 W/m2). Large animals must move and destroy biomass.

33. Human body poweris about 100 Watt, or about 300 Watt per sq. meter The biosphere provides only 0.5 Watt per sq. meter 4. Large animals have to move and destroy biomass

34. Large animals have the potential to destroy terrestrial ecosystems.

35. Energy consumption in a stable ecological community Distribution of primary energy consumption over organisms of different size in stable ecosystems. The smallest organisms (bacteria, fungi) consume over 90% of total energy flux; the medium-sized (invertebrates) – about 10%, and all organisms with body size exceeding 1 cm are allowed to consume altogether no more than about 1% of primary productivity. The largest organisms consume the smallest share of ecosystem productivity in stable ecosystems. Humans have exceeded their quota by an order of magnitude. Makarieva A.M., Gorshkov V.G., Li B.-L. (2004) Ecological Complexity, 1, 139-175.

36. Territorial requirements Kelt D.A., Van Vuren D.H. (2001) The Ecology and Macroecology of Mammalian Home Range Area.The American Naturalist157: 637-645. Human individual territory, implied by biological properties, is ~4 km2

37. Stores and fluxes of information in the biosphere and civilization Cultural heritage of humans is unprecedented in the biosphere. Human ability to destroy the biosphere is also unprecedented. However, the complexity of biotic regulation is far beyond human possibilities. Biotic regulation cannot be replaced by technology.

38. Some conclusions • Ecosystems with high biomass (large abundance of organic matter) are intrinsically unstable. Such are terrestrial ecosystems that drive the biotic pump. • All large herbivorous animals, including humans, are potentially able to arrange an ecological catastrophe on land. • The only strategic solution for sustainable existence of the humanity is via a significant reduction of global population numbers.