Arnold De Loof

Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, University of Leuven, Belgium. Address: Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium.

E-Mail: arnold.deloof@bio.kuleuven.be

Abstract

It is very logical to first formulate an unambiguous definition of Life before engaging in analyzing the parameters instrumental to its evolutionary change. However, nearly everybody assumes that catching the essence of Life in a single sentence that coherently lists all previously described properties of living matter is impossible. Yet a plausible but as yet undervalued definition that meets all essential criteria according to some philosophers of science already exists since two decades. It starts from the observation that all living matter is invariably organized in sender-receiver compartments that incessantly handle information (= communicate), thereby solving problems, most of it in an automated way. It reads: The verb ‘Life’ (as an activity) denotes nothing else than the total sum of all communication acts executed, at moment t, at all levels of its compartmental organization: L = ∑C. The key question in evolutionary theory becomes: “How can signaling activity change using both neo-Darwinian genetic- and Lamarckian non-genetic mechanisms?” At the cellular level, any act of communication is a problem-solving act because any message is coded. Hence it can be logically deduced that not Natural Selection itself but communication/problem-solving activity preceding selection is the universal driving force of evolution.

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Introductory remark

This invited paper is a concise compilation of 3 recent papers that describe in more detail the essence of Mega-evolution. For the complete set of figures, see the Open Access papers:

De Loof, A. 2014. Organic and cultural evolution can be seamlessly integrated using the principles of communication and problem-solving: The foundations for an Extended Evolutionary Synthesis (EES) as outlined in the Mega-Evolution concept. Life: The Excitement of Biology 2(4):247-269. http://dx.doi: 10.978444/LEB2(4)DeLoof.01

De Loof, A. 2015b. How to deduce and teach the logical and unambiguous answer, namely L = ∑C, to “What is Life?” using the principles of communication? Communicative & Integrative Biology. http://dx.doi.org/10.1080/19420889.2015.105977 (accepted and scheduled to be published very soon)

De Loof, A. 2015c. From Darwin’s On the Origin of Species by Means of Natural Selection… to The evolution of Life with Communication Activity as its very essence and driving force (= Mega-Evolution) Life: the Excitement of Biology 3(3) 153-187.

Introduction

The subject of micro-evolution is the change in allele frequencies that occur over time within a population. It is relevant to the emergence of new species. Thanks to Charles Darwin [1] and Alfred Russel Wallace [2] evolutionary theory with focus on species formation and Natural Selection as its driving force was founded. Macro-evolution acts on a scale of separated gene pools. It occurs at or above the level of species. Mega-evolution is a recent approach that takes into account recent insights in fundamental biological/biochemical/physiological processes [3]. It does not specifically focus on genetic changes like micro- and macroevolution do. It attempts to describe the evolution of ‘Life’ in its totality, irrespective of the way ‘Life’ manifests itself in the wealth of prokaryotic and eukaryotic species and their communities. Such approach requires that one first unambiguously defines what ‘Life’ exactly is before engaging in analyzing the various mechanisms/parameters instrumental to its change in the long run (evolution). From the standpoint of philosophy of science this is the logical way to proceed. Yet, such approach did not really get ground in the mainstream of current evolutionary theory, as exemplified in the formulation of the neo-Darwinian New Synthesis (NS) [4, 5, 6, 7, 8 and many others). Kutschera and Niklas [9] summarized the historical development of the term New Synthesis, from George Romanes who introduced the term to refer to the version of evolution advocated by Alfred Russel Wallace [2] and August Weismann (1834-1914) with its heavy dependence on Natural Selection, to Stephen J. Gould [8].

The main reason for the duality in which theory and practice do not match resides in the widely accepted idea that it is impossible to catch the nature of Life in a single sentence, a statement that features in textbooks of general biology, edition after edition for at least half a century up to the present (e.g. in Raven et al. [10]. Such (unwarranted) statements restrain younger newcomers who have an interest in such a fundamental question to engage in searching for a plausible answer.

This paper recapitulates these recent papers [11, 12, 13] describing that if one first defines ‘Life’, a novel paradigm emerges which brings unity in Biology, and which also enables us to answer the question whether Natural Selection should be replaced by Problem-solving activity as the universal driving force of evolution.

An unambiguous definition of Life has already been deduced 20 years ago

In the late 1980’s, I was challenged by my undergraduate students to come up with a plausible definition to “What is Life?”, this to make me more credible as a professor of biology, the science of Life. Their reasoning was: “Why should we engage in the study of Life (= Biology) if one cannot define what ‘Life’ is”?. I accepted the challenge but I soon experienced that many had tried before me, without much success. No wonder as one gets confronted with all the criteria a good definition of Life should meet according to the philosophers of science Schejter and Agassi [14]. Their wording was: “Apart from its not being trite and uninformative (circular, to use a traditional term), it should be neither too wide nor too narrow; it should not exclude living things and it should not include dead ones. Furthermore, it should not make biology part-and-parcel of chemistry and physics (meaning that there should be room for an immaterial dimension).” I add: “and it should organize all known dimensions and properties of living matter in a logical order and context, and it should pave the way for defining what exactly happens at the moment of Death”.

But why did (and still does) nearly everybody assume that ‘Life’ cannot be defined? To my own surprise, the very reason turned out to be the result of the combination of asking the wrong question, with an understandable but nevertheless fatal thinking error. Indeed, the common procedure at that time (the 1980’s-90’s) was to try to deduce the properties of Life by comparing the properties of ‘living matter’ with those of ‘non-living or inanimate matter’, assuming that these two conditions are true opposites like warm-cold, high-low etc. True opposites can only have one counterpart. But a given living entity, e.g. a dog can be opposed to a myriad of non-living entities: a bottle, a ring, a brick, a ship etc. Thus they are false opposites. The true opposites with respect to ‘Life’ are: ‘still alive versus ‘just dead’. This urges for answering: “What exactly changes at the very moment of Death?” Answering that question in a non-circular way e.g.”death ensues when life ends” imparted the following insights that: 1. Death ends an activity of a given system. That activity turned out to be communication activity of systems organized as sender-receiver communicating compartments; 2. There are numerous degrees of communicational complexity of most living systems, at least 16 in my classification system (see later).

The following definitions emerged:

Death ensues when a given communicating compartment irreversibly (to exclude regeneration) loses its ability to communicate at its highest level of compartmental organization, the total number of such levels . It follows that the essence of being alive, or of ‘Life’ as an activity, is communication activity. Communication. Numerous definitions of communication have already been formulated one more complex than the other, but seldom all encompassing. My preferred definition reads: “Communication is transfer/handling of information in a system organized as a sender-receiver communicating compartment” (Fig. 1A). Any act of communication is generated as follows. A sender or the environment produces and releases a message(s) which is always written in coded form into what is called ‘a communication channel’ (blood, water, air etc.). The message (usually transported with the help of some carrier) will eventually arrive at a competent receiver (= with matching receptors). Here it will be captured, decoded, amplified and responded to by causing the mobilization of part of the stockpiled energy to do some ‘work’ sooner or later, e.g. by engaging in feedback. Depending upon the complexity of the system, numerous acts of communication can be simultaneously executed. All parts of any communicating compartment are subject to change; the sender, the message/messenger system, the transmission channel, the receiver, the feedback loops etc.

Feedback is not a circular but a spiral-like unidirectional activity (Fig. 1B). When the complexity of a signaling system increases, the possibility for generating more than one answer may arise; this happens at bifurcation points (Fig. 2B. In my opinion this necessity to make a choice is the very basis of ‘free will’. The more bifurcation points, the more possibilities for making use of free will.

Figure 1. The classical sender-receiver compartment (A) is a better alternative than the cell for functioning as the universal unit of structure and function of all living matter. Feedback is a spiral-like, unidirectional process (B). At bifurcation points, a choice has to be made as to how to proceed with communication. In digital-era wording, the Temple of Life has only 4 pillars (C), in contrast to the classical PICERAS Temple of Life that has seven. From De Loof (2015c).

Information. My definition of information reads: A message contains ‘information’ when, upon being decoded by a competent receiver (= a receiver with the proper receptor(s)), part of the stored energy in that receiver is mobilized for doing some sort of ‘work’. This is the meaning of AT WORK in Fig. 1A. Information is itself immaterial, but it usually needs a carrier for being transported [12]. A logically deduced unambiguous definition of Life (as an activity) reads: ‘Life’ sounds like a noun, but it is a verb. What we call ‘Life’ is nothing other than the total sum of all acts of communication exerted by a given sender-receiver compartment at moment t, at all levels of its compartmental organization (cell organelle, cell, tissue,…, whole organism,…, population, community, Gaia level). The simplest symbolic notation reads: L = ∑C [12, 15].

Because “Life” is an activity of a given sender-receiver compartment of which there exist many different forms, one can specify it further as:

L= Life; S= type of compartment; t = moment at which the communication acts are executed; 1 = lowest level of compartmental organization (1 = prokaryotic cell or cell organelle in a eukaryotic cell); j = highest level of compartmental organization (cell, tissue, organ, organism, …, aggregate, …, population, community, the Gaia-level). For a symbolic notation that highlights how to compare ‘biological’ and ‘mechanical’ life (e.g. computer-life), see [12,15].

Thus ‘Life’ has both a qualitative (nature of the communication acts) and a quantitative (number of communication acts) aspect.

As to the origin of ’Life’: it came into being at the very moment that the first act of communication was executed [3, 16]. Fig. 2. illustrates this event in cartoon form (from [11]). How in pre-biotic conditions a living entity could have come into existence chemically has been discussed by Guth [17, 18]. The reasons why I think that the synthesis of actin-like molecules may have preceded the synthesis of RNA or DNA as information carriers have been outlined in [16].

Figure 1. Cartoon illustrating my view that Life came into being at the very moment that the first act of communication was executed. Which act that was and under which environmental conditions this happened is unknown. Adapted from De Loof [3, 11].

Time. If one thinks that the definition of ‘Life’ also requires that ‘Time’ has to be defined as well, I tried to do so: In my opinion ‘Time’ is invariably a property of a given energy-converting system. It is a measure for the inertia of the conversion of a given form of energy (heat, light, chemical etc) into another form(s) plus increase in entropy of the system (second law of thermodynamics). There are as many different times as there are energy converting systems [3]. This definition does not at all unveil why there is inertia in energy conversion, thus why such conversions do not proceed at an infinitely high speed. This continues to be a big mystery in physics. Evolution of Life

If L=∑C is an acceptable symbolic notation for ‘Life’, the simplest symbolic notation for its evolution becomes:

ΔL(T 2 -T 1 ) = Δ∑C(T 2 -T 1 )

Some of the novelties in Mega-evolution as compared to classical evolutionary theory (neo-Darwinian New Synthesis)

4.1. The common descent principle was never better documented

This principle represents the very heart of Darwinian/Lamarckian evolutionary theory in both the New Synthesis and in the Mega-Evolution approach. Today it is very well experimentally documented [19[. In the past, a truly major novel insight has been formulated by the late Lynn Margulis. According to her symbiogenesis theory (1981), the eukaryotic cell came into being when at least 3 different ancient prokaryotic species established a functional symbiotic novel level of compartmental organization. Later in evolution, ever more complex multicellular eukaryotic entities came into being, requiring ever more complex coordinating signaling systems. The consequence of Margulis’ theory is that, in fact, all life forms on the planet earth, thus both the contemporary ‘genuine’ prokaryotes as well as all eukaryotes are manifestations of the only existing planetary form of life, which is bacterial in origin and nature. No other forms of life are known. According to [21] acquiring genomes was an important issue in the origins of species.

4.2. Not ‘the cell’ but ‘the sender-receiver’ as the universal unit of structure and function of all living matter

It has been outlined before [3, 11] that the ‘sender-receiver’ (Fig. 1A) better serves the role of universal unit of both structure and function of all living matter than ‘the cell’. In origin the term ‘cellulae’ was used by Robert Hooke (1635-1703) to denote the small chambers in cork. Later Schleiden and Schwann described that all living matter is made up of ‘cellulae’. The prokaryotic cell is the smallest sender-receiver. The Gaia-level is the highest one.

4.3. Levels of complexity in communicating compartments: more numerous than in classical biology

In introductory textbooks of biology, the usual levels of complexity are; cell organelle, cell, organism, population and community. In the Mega-evolution approach which uses communication as criterion for grouping ‘entities’, there are at least 16 levels of compartmental organization in living matter. This has been described at length elsewhere [3, 11]. The ≥ 16 levels can be grouped into three categories. Witzany [22] handles a similar communication-based classification system.

Compartments restricted to a single individual (levels 1-8): prokaryote, eukaryote, cell aggregate, syncytium, mono-epithelium, polyepithelium, segmented organism, tool utilizing compartment. Compartments with individuals of the same species (levels 9-14): colony, heterosexual and social compartments, baby inside mother (internal budding) compartment, population/species, electrosphere compartment (e.g. humans linked by telephone, radio etc.). Compartments with individuals belonging to different species (levels 15-16): the community (with nutritional and/or protective aspects), and the planetary or Gaia compartment.

In classical evolutionary theory the main focus is on the population and species (genetics), which is level 13 (out of 16) in my classification system that takes into account the signaling pathways at all levels.

4.4. Instead of ‘Body and Mind/Soul’ rather ‘Hardware and Software’

One of the many reasons why it took so long before a plausible definition of Life was formulated [15] resided in the absence of an adequate vocabulary. The dichotomy ‘Soma or Body’ and – for humans- ‘Soul’ or ‘Mind’ reigned in Western culture for millennia. In Asian culture, that distinction was less clear-cut. Yet, defining ‘Soul’ was not evident. The term disappeared from the core of Psychology as a discipline (psyche = “soul” in Greek),but it continues to be an essential element in (some) religions. The question whether only humans have a soul or whether other organisms, in particular animals, also have a soul and are conscious, is no longer a scientifically valid question, but it continues to be asked again and again [23]. It is better replaced by the questions how the cognitive memory works, how widespread such memory system is and what its relation is with consciousness and problem-solving. Since the start of the digital era, the terms hardware and software (Fig. 1C) became widely accepted for computers. In biology and in particular in evolutionary theory, they are useful [3, 12, 13], be it that this is not yet common practice. ‘Hardware replaces ‘Soma’. Chemically the hardware of organisms is made up of fossil stardust ([3]. “Software” helps to describe some aspects of the cognitive memory. It is not a substitute for ‘Soul’.

4.5. Organisms have two memory systems. Two possible types of progeny

Like any sender-receiver all prokaryotic or eukaryotic cells on earth have probably two memory systems, a genetic- and a cognitive one, each with its own set of rules. The first central dogma DNA →RNA → Proteins [24] represents the very heart of the functioning of the genetic memory. Today its functioning is well understood. In contrast, despite all progress in the neurosciences, the biochemical functioning of the cognitive memory largely remains a black box [25]. One of the results is that “All inclusive inheritance” [26] uses heredity (= through genes) for all transfer of information to the next generation instead of transferability of information to the next generation (and laterally as well) which allows also taking into account teaching-learning involving the non-genetic aspects of the cognitive memory.

Physical children are the progeny generated through the principles of the genetic memory that underlies the formation of the hardware of organisms. Pupils are the progeny generated through the cognitive memory system.

4.6. Any act of communication is a problem-solving act by definition and can hence be instrumental to adaptation. Semiosis.

Why is an act of communication, at the cellular level, invariably a problem-solving act (Fig. 1A)? This follows from the fact that any message, whatever its nature is coded. Hence, when the message (often, if not always transported with the help of some carrier) arrives at the receiver and is captured there, it next needs to be decoded before it can trigger the receiver to ‘do something with it’, either instantly, or later after storage for some time, or it can be deleted. We understand our mother tongue but no other (foreign) languages because in our childhood our parents, family members, our broad environment etc. installed – by teaching – in our brain the decoding programs for our mother tongue. That gives us the impression that understanding our mother tongue is not a problem-solving activity. This interpretation is wrong; it is an automated decoding activity. The causal link between signaling and problem-solving is not commonly emphasized in the exact biological sciences, contrary to its status in the humanities, in particular in linguistics. Here the term ‘semiosis’ or ‘sign process’ is routinely used [27, 28, 29, 30 and others]. It was introduced by Charles Sanders Peirce (1830-1914) to denote any form of activity, conduct, or process that involves signs, including the production of meaning. I agree with Kull and Emmeche [29] that because it incessantly interprets signs and signals, “Life is semiosis”. My wording L = ∑C [15] said the same but in the wording of the exact biological sciences.

4.7. Adaptation to an environment poisoned by high Ca2+-concentrations

Organisms have to adapt to changing external conditions. The environment can become dryer, wetter, colder, warmer, less rich in food supply, populated by more parasites etc. When chemical pollution as an adverse condition is at stake, one usually thinks at man-caused pollution by pesticides, heavy metals, CO 2 etc. Yet the most toxic pollutant on earth (O 2 not taken into account) is the omnipresent Ca2+-ion. This may look strange because we encounter the beneficial aspects of Ca2+ in our daily life: our calcareous bony skeleton, Ca2+-rich milk, the egg shell of birds, and Ca2+ as a secondary messenger [29]. Yet, because above a very low threshold a rise in cytoplasmic Ca2+ concentration is very toxic as it causes changes in the conformation of some essential macromolecules, in particular proteins. In fact it is because of this toxic effect on proteins that Ca2+ can act as secondary messenger. The intracellular Ca2+ concentration in the cytoplasm of unstimulated cells amounts to about the vey low value of about 100 nanomolar. The extracellular concentration is many orders of magnitude higher, namely about 1-60 millimolar (2 mM in blood). Thus there is a gradient of about 100,000 times in Ca2+-concentration cytoplasm-outside cells. If the intracellular Ca2+-concentration rises too much for too long, cells can get damaged and may even enter the apoptosis cell death cycle (Calcium-induced apoptosis: Orrenius et al. 31]). The duration of the heart contraction cycle which is based upon periodic Ca2+-release from the SER followed by fast re-uptake is an indication of what “too long” means, namely in the order of seconds rather than of minutes in most cell types. The toxicity of Ca2+ means that cells have to continuously fight against the influx of excess Ca2+ from the outside world (environment). Their major weapon is the different types of ATP-driven Ca2+-ATPases in both the plasma membrane and in the internal membrane systems. The cellular system for maintaining Ca2+-homeostasis and other types of homeostasis as well, a most important issue in cellular physiology and evolution is complex [32, 33, 34]. It is in this context that the self-generated inorganic ion-based cellular electricity and the lipid nature of cell membranes has to be understood. This is well worded by John Torday [33] as” The history of physiologic cellular-molecular interrelationships can be traced all the way back to the unicellular state by following the pathway formed by lipids ubiquitously accommodating calcium homeostasis, and its consequent adaptive effects on oxygen uptake by cells, tissues and organs”.

Lipid membranes are not permeable to inorganic ions unless they harbor proteinaceous ion channels and pumps. They are permeable to electrons which means that self-generated cellular electricity could not function if it were electron-based. Self-generated inorganic ion-based electricity is vital to life. A cell is dead when its electrical dimension collapses [35, 36]. An overlooked key feature of cells is that all cells are able to drive an electrogenic electrical current through themselves, at least during part of their developmental cycle, and that they are polarized (for figures, see [13]. This is contained in “The cell as a miniature electrophoresis chamber concept” [35].

4.8. Not Natural selection but problem-solving activity preceding selection is the universal driving force of evolution

Neo-Darwinists hearing somebody contesting the generally accepted view that Darwin’s Natural Selection is the universal driving force of evolution probably experience this as cursing in a cathedral. Metadarwinists may consent (see website: The third way of evolution [37]). The problem for both is that at present it remains difficult to clearly define the mode of action of Natural Selection and to present examples where it has been at work [38]. If selection would nevertheless not be the driving force, what is the alternative? I argue that if one changes paradigm away from the NS by starting to define at first ‘Life’ and next analyses what mechanisms may be instrumental to its variability, problem-solving activity preceding selection emerges as the long-sought for alternative. In a former paper [13], I used the example of students doing an exam to illustrate this principle. The general perception is that the examiner, not the students taking the exam does the selection. Yet, if one analyses the system, the opposite conclusion emerges. The teacher-examiner formulates the questions. In evolutionary wording, he/she constructs some gradient, like nature would build temperature-, light- etc. gradients. It is up to the students to show their ability to overcome the exam-gradient. Thus, they engage in self-selection, a principle advanced by [3] as ‘Gradient-Provoked Swelling/Shrinking Self-Selection or GP-Triple S Principle’. The examiner only lists their success or failure. The principle of self-selection is further strengthened when the student succeeds in solving the problem by feedback, i.e. by answering in such a way that the sender/teacher will (deliberately or not) lower the gradient (e.g. by changing the subject of examination).

But problem-solving activity is inherent to communication activity which itself is a synonym for Life (as an activity). This leads to the unexpected and counterintuitive conclusion that Life itself is the driving force of its own evolution. In other words, the principle of Life being an activity of compartments that are invariably organized in sender-receiver entities contains the endogenous mechanism for driving its own evolution. In my opinion, this is a magnificent principle.

4.9. Cultural evolution is evolution “the software way”

Neo-Darwinism did not yet succeed in plausibly incorporating cultural evolution into the mainstream of evolutionary theory [11]. The main reason is that the New Synthesis reduces all causes of variability under the common denominator of genetic changes (Fig. 3).

Figure 3. Major genetic and non-genetic causes of (Communicational) variability. Not only Charles Darwin (1809-1882) but his contemporary Alfred Russel Wallace (1823-1913) as well independently conceived the theory of evolution through natural selection. Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck but commonly referred to as simply Lamarck is best known for his theory of inheritance of acquired characteristics that was proven wrong in the context of classical genetics. Epigenetics is a form of temporary transfer of genetic information (through DNA- and/or histone modification) to the next (few) generation(s). According to some researchers such transfer is Lamarckian in nature. Cultural evolution is also mainly Lamarckian in nature.

As long as one assumes that the principles of the cognitive memory are inherent to those of DNA → RNA → Proteins, this assumption is the only possible one. But the assumption is wrong. The cognitive memory system has its own rules and mechanisms which include self-generated electrical activity. This activity is based on the transport of inorganic ions, and thus only partially dependent upon the central dogma [24]. Cultural evolution is mainly achieved through the possibilities of the cognitive memory. In digital era wording, it is evolution ‘the software way’ while organic evolution is evolution ‘the hardware way’, using the principles of the genetic memory [11]. In fact, organic- and cultural evolution are the two sides of the very same coin, which is evolution of Life with its two memory systems. As stated before, cultural evolution is achieved through pupils who function as the software progeny counterpart of physical children.

4.10. Evo-Devo. Haeckel’s “Ontogeny recapitulates Phylogeny”.

Development may be regarded as the accumulation of changes during lifetime, thus as evolution in the very short run [39, 40]. The key issue in development is the differential use of the same genome in all cells of a differentiating organism, a few exceptions not taken into account. The generation of cells which all differ in their membrane-cytoskeletal properties by what has been called ‘The double asymmetry principle’ (for figure see [13]) is causal to this differential use of the same genome [41, 42]. There is no role for mutations in development, this in contrast to long-term evolution in which mutations do play a key role. In my opinion, Ernst Haeckel’s law “Ontogeny recapitulates phylogeny” remains a valid key concept in evolutionary theory.

5. Discussion

The 2014 Nature paper of Laland et al. [43] shows that among evolutionary biologists the conviction is gaining ground that the neo-Darwinian New Synthesis needs an upgrade, but unanimity on this opinion has not yet been reached. Whether one is pro or contra an upgrade may be influenced by one’s major study object. If one focuses on sessile organisms like e.g. plants, one may be inclined to assume that the NS explains well enough the mechanisms of evolution, some details not taken into account. If one focuses more on free living organisms like e.g. animals, one may favor the view that some systems partially direct their own evolution [44], and therefore an upgrade is urgently needed. Free living organisms benefit more from adaptations in mobility and from the possibilities offered by the cognitive memory system for elaborating strategies for improving their survival and reproductive success. Another cause of pro-contra thinking may concern the type of evolution one is interested in. The humanities are primarily interested in ‘cultural evolution of the Homo sapiens. The exact biological sciences consider the Homo sapiens not as a special case for which another type of evolution needs to be invoked, but as one of the numerous terrestrial species. They are more interested in the organic-chemical evolution of this and other species, no matter whether they live in an aquatic or terrestrial habitat.

If one agrees that the numerous novel insights generated by the novel disciplines in biology [13, 45, 46, 47, 48, 49, 50, 51 etc.] need to be incorporated in an extended evolutionary new synthesis, one faces the question how such integration and unification can be achieved. The importance of communication for understanding Life and its evolution has been approached in various ways by e.g. [15, 29, 52, 30, 33 and others]. In my opinion, the most straightforward approach is to start from a plausible definition of Life that is acceptable to both the humanities and the exact biological sciences. Communication activity executed by sender-receiver compartments is the key issue in such definition [12, 15]. It leads to the question how the architecture and functioning evolved from the probably simple Progenote as the primordial sender-receiver into the multitude of organismal and supra-organismal entities that function as sender-receivers.

Neo-Darwinists and Metadarwinists both agree on the common descent principle, the very heart of Darwinism. They differ in opinion(s) on a number of topics, e.g. on the relative importance of epigenetics, on the weight one should give to the overall importance of genetic changes as instrumental to bringing about (all) evolutionary change as well as on the significance of Natural Selection as the universal driving force of evolution. NS primarily focuses on the effects of all kinds of mutations (Fig. 3) and on species formation through the possibilities of only one memory system, namely the genetic memory and the central dogma DNA → RNA → Proteins. This is apparent from the formulation of ‘the all inclusive inheritance principle’ [26] that acknowledges that in addition to all sorts of mutations, there are indeed other causes of variability instrumental to evolution. But in the end their effects can all be explained by one memory system, the genetic one. But cells/organisms have in addition to their DNA memory, a cognitive memory system. Although it continues to be a (biochemical) black box, there is no reason to neglect its existence and importance. Darwin did not know the principles of the genetic memory but he took them into account. As a result, NS fails to adequately incorporate cultural evolution into the mainstream of evolutionary theory. This type of evolution relies more on the cognitive memory system. As long as NS does not accept a software upgrade, it will remain a theory of the evolution of the hardware of living matter as governed by the principles of genetics. Such type of evolution is very slow. It usually (but not always) operates at the geological time scale. Mega-evolution takes two memory systems into account. Through teaching and learning which are mainly enabled by the cognitive memory, evolution by non-genetic mechanisms (which is ‘evolution the software way’ in my approach) can be very fast as illustrated by the recent evolution of the species Homo sapiens. Another example is the coming into existence of a new Darwin finch species on the Galápagos island Daphne Major that took only 4-5 generations, starting in 1981 [53]. These data illustrate the power of the introduction of a dialect in a language as instrument for reproductive isolation, an important issue in species formation.

Some people may not like the idea that our body is in fact a clump of some 100,000 billions (= 1011) eukaryotic cells that by themselves are the symbiotic result of a few (3?) ancient bacteria. Mitochondria are modified bacteria. Each eukaryotic cell contains several mitochondria. In addition, numerous bacteria live on the surface and in the alimentary canal of animals. All these subcellular and cellular entities have to cooperate which means that the communication networks (signaling pathways) inside any multicellular organism are numerous. The complexity can be orders of magnitude higher in populations, communities etc. In a recent (2015) internet discussion forum) Kalevi Kull posted the quote that “Life is semiosis. Life is a network of sign processes and that this is obviously the most exact and brief definition of life”.

I advocate replacing the widely accepted concept that “Natural Selection is the driving force of evolution” by “Problem-solving activity preceding selection (like when doing an exam) is that universal force”. One could argue that in the end it does not make much difference: the best adapted (which are not necessarily the ‘strongest’ ones) will do better. Yet, the formulation does make a substantial difference because it necessitates answering the question which biological principle enables problem-solving. The answer is that problem-solving does neither follow in full from the central dogma nor from the fact that all living matter is cellularly organized. It is inherent to the organization of all living matter in senders-receivers that continuously handle information, thereby solving problems, most of them in an automated way. This approach necessitates that one rethinks several aspects of evolutionary theory. For example, should one continue to attribute so much weight to “species formation”? Or, what is the unit of selection: the cell, the organism, the species etc. or the signaling pathway as instrumental to problem-solving or the sender-receiver compartment? How to better incorporate the principles of physiology in evolutionary theory [13, 48, 54].

Because of the multitude of signaling pathways and their endless interactions the scope of Metadarwinism (in particular the MENS approach as explained in [13] and in this paper) is much broader than that of NS. MENS is better rooted in physiology, a weak point of NS. Instead of ‘heredity’, MENS prefers “transferability of information to the next generation(s) (and where relevant, laterally as well) by all means, thus also by the possibilities of a second memory system, the cognitive memory. This way it manages to seamlessly integrate both organic- and cultural evolution [11].

The Mega-evolution approach urges for changes in teaching biology. For the moment textbooks of biology seldom explain the principles of communication, probably because the authors assume that these principles are self-evident (because we communicate all the time without any problem), and that therefore they do not need extensive explanation. In reality, the opposite is true. The fact that most communication happens in an automated way indicates that it is far from simple. How could it become automated? Upon analysis, it becomes clear that the mechanisms of communication are at least as sophisticated as those of genetics. In particular, the role of the cognitive memory in signaling is still a black box, despite all progress in neurobiology.

In the recent past I repeatedly stated that, paraphrasing Theodosius Dobzhansky (1973), “Nothing in biology and evolutionary theory makes sense except in the light of the ability of living matter to communicate, and by doing so, to solve problems”. Given its continuing observational and descriptive nature the discipline of Biology keeps missing a unifying principle comparable to E = mC2 for physics or the atomic model for chemistry. Torday [34] summarized this with the characterization by Earnest Rutherford as ‘stamp collecting’. In my opinion, if properly incorporated in teaching L = ∑C harbors the potential for shedding the (not fully mistaken) perception that many biologists insufficiently grasp in full the very nature and importance of the principle that can integrate all subdisciplines of Biology, namely communication.

Acknowledgements

I thank all students and colleagues who helped me to streamline my communication-based view of evolution. My thanks too to Julie Puttemans, Marijke Christiaens and Katrien Becuwe for help with the figures, and to Michael Gaffney for text correction.

Conflict of interest

None.

References

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Legends to Figures

Figure 1. The classical sender-receiver compartment (A) is a better alternative than the cell for functioning as the universal unit of structure and function of all living matter. Feedback is a spiral-like, unidirectional process (B). At bifurcation points, a choice has to be made as to how to proceed with communication. In digital-era wording, the Temple of Life has only 4 pillars (C), in contrast to the classical PICERAS Temple of Life that has seven. From De Loof (2015c).

Figure 2. Cartoon illustrating my view that Life came into being at the very moment that the first act of communication was executed. Which act that was and under which environmental conditions this happened is unknown. Adapted from De Loof (2002, 2014).

Figure 3. Major genetic and non-genetic causes of (Communicational) variability. Not only Charles Darwin (1809-1882) but his contemporary Alfred Russel Wallace (1823-1913) as well independently conceived the theory of evolution through natural selection. Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck but commonly referred to as simply Lamarck is best known for his theory of inheritance of acquired characteristics that was proven wrong in the context of classical genetics. Epigenetics is a form of temporary transfer of genetic information (through DNA- and/or histone modification) to the next (few) generation(s). According to some researchers such transfer is Lamarckian in nature. Cultural evolution is also mainly Lamarckian in nature