Intelligent characteristics of potential microbial life during the LHB

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Intelligent characteristics of potential microbial life during the LHB

Ian von Hegner

Abstract

The `disparitas conjecture ' states that unicellular life is common in the galaxy but that multicellular life is rare in comparison. A variation of this conjecture is that unicellular life may be common in the galaxy but that intelligent life is rare. However, microbial life can and does indeed display characteristics of intelligence. Thus, in this work, how life could have potentially endured through the Late Heavy Bombardment (LHB) through intelligent strategies such as decision-making, association and anticipation, communication and self-awareness was investigated. At the LHB, there would have been, for microbial life, an unpredictable environmentalfluctuation regarding pools ofamino acids, lipids andfluids available when impacts and reimpacts launched organisms into new habitats. Thus, evolutionary strategies must have been favoured that could stretch the available external and internal resources as long and as efficiently as possible. Thus, inclusive fitness or kin altruism could have emerged, where organisms adapt to acquire energy and nutrients from siblings who voluntarily autolysed to replenish the amino acid pool for their kin. A further strategy could also evolve where members of the same species can recognize each other and actively isolate themselves from other species, which allows them to better utilize the amino acid pool. Thus, the organisms will potentially be able to survive for a long time in this manner until new impacts launch them to new spots with amino acid pools. There has thus been an alternating increase and decrease in the number of organisms during this localized planetary reseeding, and life may have endured this way until the bombardments were over. Thus, if a world inhabited only by analogous bacteria, archaea andprotists is located elsewhere in the galaxy, the existence of intelligent life there cannot be excluded. Keywords: astrobiology, bacterial altruism, localized planetary reseeding, the Hadean.

Introduction

Whether there is life elsewhere in the galaxy and beyond is a much-discussed topic, marked according to how probable the emergence of life and its subsequent evolution is considered to be. However, an ongoing search for exoplanets and exomoons with conditions suitable for life as we know it and a search for worlds actually having life are occurring.

In the search for life elsewhere, the informal middle position has emerged, which states that unicellular life is common in the galaxy but that multicellular life is rare in comparison. This `disparitas conjecture' or `disparitas hypothesis' may explain the reason for the silence we observe when we search the galaxy for traces of technosignatures such as radio transmissions. After all, in the majority of the Earth's history, life has existed in the form of unicellular life and is, in fact, still the dominant form. In terms of reproductive fitness, it is also the most successful lifeform known, existing in virtually all terrestrial habitats.

A natural extension of the discussion about life elsewhere is the discussion about intelligent life elsewhere. Thus, an occasionally heard variation of this middle position is the view that unicellular life may be common in the galaxy but that intelligent life is rare. This seemingly trivial variation is important to address, as it follows that if during a search for intelligent life one locates a world where only microbial life exists, the possibility of the presence of intelligent life on that world is excluded. This has nontrivial implications, as the notions that microbial life is common but that intelligent life is rare are self-contradictory.

Thus, in microbiology, the convergent attitude is that microbial life can and indeed does display characteristics of intelligence. While a single microbial organism can be said to be an automaton (which may itself be debatable), macromolecular networks can confer intelligent characteristics in microbial organisms. Thus, microbial organisms do indeed display characteristics of intelligence such as decision-making, association and anticipation, selfawareness, robust adaptation, and problem-solving capabilities (Westerhoff et al., 2014). If a world exists where only microbial life thrives, the probability of intelligent characteristics associated with this life is also high. Therefore, the conceptual distinction between microbial life and intelligent life is a misnomer in the debate that should be moved away from, and a more precise terminology regarding the search for life elsewhere is needed.

Life can display intelligent characteristics in many different situations. As an illustration, a scenario relevant to astrobiology can be considered. The Earth has been impacted ever since its formation approximately 4.5 billion years ago, although the frequency and size of these impactors have declined since the Late Heavy Bombardment (LHB) (Reyes-Ruiza et al., 2012). This event, which may have been due to discrete early, postaccretion and later planetary instability-driven populations of impactors (Bottke and Norman, 2017), began approximately 4 billion years ago and is estimated to have ended 3.8 billion years ago, although some evidence indicates that terrestrial impacts did not cease but rather waned gradually until approximately 3.0 billion years ago (Lowe et al., 2014).

While much remains to be elucidated regarding the details, an autonomous cell with a high degree of certainty existed on the Earth 3.5 billion years ago, in the Archean Eon (Schopf et al., 2007), dated to span between 3.8 and 2.5 billion years ago (Coenraads & Koivula, 2007). However, the chemical evolution leading to this life was probably not a single event; instead, the transition from chemistry to biology was a gradual series of thresholds of increasing complexity over time (von Hegner, 2021). Thus, some lines of evidence point to the emergence of life occurring earlier, between 4.1 to 3.5 billion years ago (Bell et al., 2015), in the Hadean Eon, dated from the end of the Earth's accretion until 3.8 billion years ago (Coenraads & Koivula, 2007).

The Hadean and early Archean world was in many ways an alien world compared with the current Phanerozoic world. Thus, the presence and composition of primitive continents at that time have been under intense debate. A study estimates that the few very large impactors that impacted the Earth would have resurfaced less than 25% of the planet's surface, meaning that most of the crust was not melted or thermally metamorphosed to a significant degree (Abramov & Mojzsis, 2009). Another study suggested that a large landmass existed in the Hadean world, with an environment that could have included nearly all geochemical conditions that favour the chemical evolution of life (Maruyama et al., 2013).

Several hypotheses regarding where and how life could have arisen have been posited over time. Life may, for example, have started at hydrothermal vents at the ocean floor, but it could also have started at shallow ponds in what has been called Deamer's `hot little puddle' (Damer, 2019), a modern version of Darwin's `warm little pond'.

If life indeed existed in the period when the LHB took place, the LHB must have had an influence on life, and life must have faced scenarios differently from those in later times. One such scenario is that at the LHB, the incoming impactors would have meant that there was an unpredictable fluctuation of available building material for the organisms, or in other words, that there would be a depletion of a pool of amino acids, lipids and fluids available for a cell. Thus, it is puzzling to understand how life survived through this period.

There are many variables to consider, and many microbial strategies may have been at play and tested through the LHB. However, the LHB has provided an environmental pressure different from anything else life has experienced on this planet. However, the evolutionary responses and impact dynamics can be described and predicted. Their interaction during this period may have yielded strategies different from anything else life has experienced, which could have pushed life through a unique survival strategy that has not been seen since at the same scale. Thus, the following text will examine how life could potentially have managed to survive through this period through strategies that demonstrated intelligent characteristics.

Discussion

In this article, Section 3 introduces the LHB and impact rate. Section 4 introduces the effect of the LHB from life's perspective. Section 5 introduces the course of action that life must have taken due to the restraints of the bombardment. Section 5.1 highlights the selection of organisms that can endure the longest. Section 5.2 highlights the evolution of altruism, a characteristic of intelligence. Section 5.3 highlights the evolution of cooperation, a characteristic of intelligence. Section 6 clarifies how evolutionary strategies have enabled life to make it through the LHB. Finally, Section 7 summarizes the results of this investigation as well as its limitations and strengths and its significance for the search for intelligent life on other worlds.

The Late Heavy Bombardement

Estimating how many impacts the Earth endured during the LHB is associated with considerable uncertainty, as the Earth has erased much of its own early history. A modern estimate, based on lunar cratering, radiometric data and a record of the late Archaean (3.52.5 billion years) impact flux provided by terrestrial impact spherule layers, yields an upper limit on the number of impacts in the time span of 4.5-2.5 billion years of 60000 impactors with bodies >10 km in diameter. This estimate is based on a smoothly declining flux (no LHB), while a model with an LHB at 4.0 billion years would yield approximately a factor of 100 fewer impacts in the same time frame (Marchi et al., 2014; 2021).

While the record is likely incomplete and uncertainties remain, it is also the case that these estimates apply only to large impactors. Thus, it seems reasonable to hypothesize that many smaller impactors also hit the ground but failed to leave a trace. Thus, e.g., the current- day flux of extraterrestrial material in terms of meteorites falling to the Earth's surface, where it tarn been estimated that the global АШ flux is 17,600 objects each year for masses >50 g, can be menaioneh (>goti st al.s 2020).

Mo st af ihese melooriteedo eel cause xagnifinant damage 1o tine Earth'r curfacc; however, ea is reasoaaOif io assnme fhef c scenario between fliese 1wo eotremes aiso eoisteO durino She LHB, where imractora ke^e na deaae enough to nn^^of hit farth's (шОпсє, butnch necetsarilo oapablo of loavmylraebt ia fBo prosont; eui'acd. Т1^п5'і^іі^7іЕ awd Е^опєшу moy етьч^тг geen gxeatfг tSlde Sboca of tBo 0hg7 ётрасПах, seath fSlft гай^г flian ilse oaUth tse:ing ЫС mfly by impdetors 0 l o Oot in dііпєєє^ієп eiairo fem mifltan dt t^housanO ft roes, the Earth wes ako hot an difl0rentot7oer ev^o,f year if ungorthrs abte 5o rexnn the sud'oea axh affert ihs pnteotio1 ll^s)tt:.ats for life theec. hgus, it si o^sisumoi:l lifne for t^lie take oo hkcutsion Utaf en ompaet showee sheatkmwhh Ш00 mjeaatorr °>er уте on avexage can Co ejected, x.e., ппє mpaaioi cxn be ^e^o)^o(esl eonU:

і.є., oileonсIh a.7fhoшlsomeAhnre 7nEa>h. From Піеш vohl7s, the rote oaofmoterfor the impactor shower situation is obtained:

the most ЮПєЄ, патЬо o0шfoo7tors floo wiA b e observed in a year.

At the LHB, oiero would lltm be an aliTOrt c^ontinuoai iusommg of impaceOTS on iiio Earth. Mtdoogn fleio woe a gHabaO urflux oo :^mtt^cSof^, a'ox micsobml iod, toese wouM dr;

сgnarioncen as tornafly mbfeqo7nf m^rtaea spaeadavertime andplace, re., flierewouk be ote m^redirtobte eovirogmeh(af flo7tuation m ogat new impaciswrnfld Ша ilargtajoodseon rooe orgamsms off to oew oovnomoents.

Dnriog 1mslaoes, o ring sa^,fem °s s'eimeil, art^ ts тосЫ fos і5ііі riita tystem has bsen made ian von Hegnes ^022^ сопеіпТТп|ї. о. hoo ienart1 ringa, n7metn, tofe рттале ring (no кшпи^ 5 tanioit mf the tecondaty ring toonO0nmg it nogs!, Ayinn wfU be no7n m ЄОє foflowing. 'Пшг, d:i^ fisst ffag7 oit afu renosUabofUm of iioe os a roeuh of impart dynmucs is the landing of the impactor. It will be assumed here that each ri ng initially contains N = 1 * 106 organisms avnosy gfeiri0uteU Iherughoat. Tllts qurnUitatoe osersrmnui msie oe conridereb a iow oumOaor Sdgoy ошГ jperhafis too (mge а munler flirn; noweves, for tine rsha of 7alru(otюry flstt whll 1эо assumod here.

Thus, in ring 1, the centre of impact, 100% of the 1 x 106 organisms perished.

In ring 2, 80% of the 1 x 106 organisms perished; thus, 200,000 organisms survived the impact blast.

For the next rings, 3, 4 and 5, the survival rate decreased correspondingly by 60%, 40% and 20%, respectively.

Thus, n = 2 x 106 organisms out of N = 5 x 106 organisms survived the impact blast Tr

In this model, the impactor could be considered invariant, as although the incoming impacters will vary in their diameters, densities and velocities, it is still the case that the organisms in the centre of the impact blast will perish, while some organisms in the adjacent rings will survive. The quantitative assessment that 100%, 80%, 60%, 40%, and 20% of the organisms perished for each ring outward is an assumption, based on the notion that the effect of the impact blast decreased for each ring outward.

Only local impactors are taken into account, the minimum impact velocity a small body has with the Earth is 11.2 km/s (Cordero-Tercero et al., 2016), capable of reaching down through the atmospheric shield and making an impact. Global planet sterilizing impactors are not considered here, although this rain of local small impactors may have given life tools to be better equipped against large global impactors.

In the second phase of the redistribution of life as a result of impact dynamics, some organisms are ejected into rings 6, 7, 8 and 9 as a result of the impact blast.

Thus, in ring 1 of the primary ring, 100% of the organisms will perish, i.e., no living organisms will be launched into the secondary ring.

In ring 2, 80% of the 2 x 105 organisms, i.e., a total of 160,000 organisms, are launched into the secondary ring.

For the next rings, 3, 4 and 5, the organisms are similarly launched over 60%, 40% and 20%, respectively.

Therefore, n = 1.2 x 106 organisms remain in the primary ring, while n = 8 x 105 organisms are launched into the secondary ring. A more simplified model than this will be sufficient and will be used from here on, where survivors deposited in 4 of the 5 outer rings in the secondary ring are considered to be in a ring.

Such a continuous impacting and relaunching environment can be expected to lead to the emergence of the bet hedging strategy, which was discussed by von Hegner (2022), as it was an unpredictably fluctuating environment in which it was not possible for life to obtain cues because the impactors did not hit the same place with the same frequency. Bet hedging can be characterized as a form of decision-making, a characteristic of intelligence, in that a population can maintain two variants, VRobustus and VIntervallum even when there is a uniform environment. However, other strategies may also have arisen, as there was a demand to not only survive the pressure from impacts but also to survive in changed conditions regarding the availability of a pool of amino acids, lipids and fluids.

The LHB from the perspective of life

At the LHB, the incoming impactors would mean that for microbial life, there was an unpredictable environmental fluctuation in terms of available building material, or in other words, that there would be an alternating depletion of a pool of amino acids, lipids and fluids available for a cell, as the organisms may be cut off from such an external pool when sent to a new location.

Energy would indeed be available for life in the form of energy derived from light from the sun or chemical processes; however, such available energy is not sufficient, a pool of amino acids, lipids and fluids must also be present. Thus, phototrophs, organisms that can use visible light as an energy source to manufacture organic compounds, require more than light, namely, an amino acid pool and water. Even chemotrophs, organisms that obtain energy by the oxidation of reduced compounds, either organic or inorganic, are no better off, as the abrupt change in the environment is the issue here. They are sent abruptly to new environments, so there is no time for gradual adaptations. Thus, even if they can harvest the amino acids they need somewhere, they can again be sent to a place where they cannot immediately harvest it.

In today's Phanerozoic Eon, amino acid pools can be found in most places; however, in the Hadean Eon, it could be very different. There is much discussion regarding the presence of amino acids during the early Earth (McCollom, 2013), which will not be the goal of this work. It will be assumed here that amino acids existed, either as a result of terrestrial chemical processes, as a result of extraterrestrial delivery through impactors (Chyba & Sagan, 1992; Takeuchi et al., 2020), or both, and that some organisms had evolved metabolic pathways for amino acid biosynthesis. What matters is that they existed.

What is debatable is how widely spread and available they were at the time. There may have been two scenarios when the bombardment increased.

In one scenario, there may initially have been spots with amino acid pools scattered around the planet.

In the second scenario, there may initially have been an even distribution of amino acid pools on the planet, which the bombardment has gradually transformed into a lane with spots with amino acid pools on it. In the second scenario, the organisms initially had good conditions for life, though these environments gradually narrowed as the frequency of the bombardment increased, while the organisms in the first scenario already had narrow conditions for life.

However, in both scenarios, for life, when the bombardment comes to an end, it will have become the same scenario. Thus, for simplicity, the discussion will be based on the scenario in which there was not an even distribution of amino acid pools but that they were spread unevenly around, like spots on a lane.

Life faces two potential issues when launched, as the organisms can in principle land in 2 places, an area that is sterile and one that is not. As time goes on and increasingly more impacts have occurred, this will mean that the organisms can land in areas that have and have not been sterilized by a previous impact. The environment that has not been sterilized can itself be divided into two situations.

The environment can be so different that even if there is an amino acid pool there, the microbial life is initially unable to take advantage of it.

The environment can be virtually identical to the native environment of an organism, making it easy to absorb the amino acid pool there. Thus, the first of these environments may initially have the same lack of utility as the environment that has been sterilized by the impact.

It must be said that the organisms will never arrive at an ideal environment due to the very nature of the bombardment. Thus, the arriving matter will land with the same velocity as that when they were sent up by the impact (Melosh, 1989). Thus, the incoming matter will land at a sufficiently high velocity to wreak havoc where it lands. It will not be destruction to the same extent as with an impact launch. There it was an entire impactor that landed, while here it will be fragments of material that land. Here, there will be scattered areas with the possibility of an amino acid pool.

Thus, there are 3 situations to consider.

In the first situation, the organisms are placed in an environment where there is no amino acid pool because this pool has been destroyed or was not initially present. It is possible for a world to be habitable yet uninhabited. It is also possible under certain circumstances for a region to be uninhabitable yet to be inhabited for a time. Being transported to such a spot would be similar to the transport of a person to the Atacama Desert; the person can immediately live there for a while but cannot obtain external native resources to live there indefinitely.

Thus, even if the organisms can pragmatically survive the initial arrival and placement there and the environment does not destroy them, there will not be a life-sustaining amino acid pool available for the organisms. Initially, these sterilized areas belonged to the minority, but as the bombings have hit an increasing number of areas, their number has increased, and the scale of environmental severity has increased.

In the next situation, it applies that there is an inverse proportionality between life and environments. Even if an amino acid pool were present where the organisms land, the fact is that it may be in a form they are not adapted to use. Thus, microbial life can adapt quickly to new environments, but this applies when they spread by themselves, where reproduction, variation and selection, the key mechanisms of Darwinian evolution, are at stake. However, here, the organisms are sent off abruptly to new environments without their own influence and may encounter a completely different environment. Thus, in the new environment, there may be an amino acid pool they are initially unable to utilize. This will be the issue for photostrophs and even for chemostrophs.

In the next situation, there is also an inverse proportionality between life and the environment. However, here, the environment is virtually the same as the organisms' own environment, which means that the organisms can absorb the amino acid pool.

In all 3 situations, it applies that new impacts can occur, where some organisms will again be thrown away from the impact site in all directions in the form of an expanding impact circle and land in a new place. Since this will be one of those places with no, different, or usable resources, the situations discussed will again be relevant.

Evolutionary strategies

Continuous but infrequent bombardment is a parameter that distinguishes this period of the Hadean from the present. In this situation, there have been two types of pressures for life. The first has been to survive the bombings in the highest possible numbers. The second has been to economize with the amino acid pool as much as possible, i.e., to evolve strategies that make the most of the available resources. Here, the specific circumstances have been able to push the evolutionary strategies in certain directions. Thus, since the external environment under these circumstances has not been reliable in terms of an available amino acid pool, selection favouring survival mechanisms through utilization of the only reliable amino acid pools available, namely, the limited amino acid pools available at the new site, must evolve and/ or those existing in the various organisms themselves, have evolved. Thus, during the LHB, evolutionary strategies would have been developed to economize on the internal resources.

The first and second rounds

The third stage of the redistribution of life as a result of impact dynamics is the landing of the n = 8 x 105 organisms in a new environment. It is assumed here that the first scenario described in Section 4 applies, i.e., that the organisms land in a place where no amino acid pool exists.

As discussed in Section 3, the organisms in each ring as a result of the impact blast perished at a percentage of 100%, 80%, 60%, 40%, and 20% for each ring outward from the blast. The material ejected from an impact crater follows a nearly parabolic trajectory, and when it begins to fall back to the surface, it will strike with the same velocity as when it was launched from the blast (Melosh, 1989). Thus, in the secondary ring, some of the organisms will perish in a reverse sequence like the one in the primary ring.

Thus, matter from ring 1 will land, although with no live organisms, as they were eliminated by impact.

Matter with 160,000 organisms from ring 2 will land, and 80% of the arrived organisms will not survive the landing. Thus, 32,000 surviving organisms will be deposited there.

For the next rings, 3, 4 and 5, the survival percentages will be 60%, 40% and 20%, respectively.

Thus, in total, n = 4 x 105 surviving organisms will be deposited there. In the first round, there may have been different species that arrived with the deposited material. These can compete against each other for access and utilization of the external amino acid pool that became available to them (see Figure 1). They will also compete against each other to evolve the best fit for the environment in which they arrived. However, such a strategy is costly overall, as an arms race will arise in which both parties mutually evolve mechanisms against each other.

The special circumstances of the situation are that there is only a limited external amino acid pool available, so the different species cannot continue to compete for fitness as they otherwise could in today's more ideal conditions. Therefore, even if it is assumed that half of the arriving organisms perished and released their amino acid pool, there will not be enough for all the survivors to undergo reproduction. However, there may be enough for some strains to go through several reproductive cycles where adaptations can occur.

Evolution is a short-term tinkerer, not a long-term planner. Thus, the various species may eventually run out of the external amino acid pool before the next impact potentially sends them to a place where there is an amino acid pool.

The second round begins when the amino acid pool runs out. Here, a competition to stretch the internal resources as long as possible will then occur, where the organisms will have to stretch their metabolism as long as possible to survive.

Figure 1. The initia1 situation in thetirst andsecondrouode. In Use; first; round, thoso are eademal resources ruclt titaS new adoytatione (ihontn who сЬнщь0; eolouroi str loos a^redi; sit<3<s:iiss Otyreon ond yellow) con oconr tn thu tetond round wiri moemal oesooroest orotuosms пгє suenttiat oi^^doanp'die^ in a itoc0aatic mynner(shoavn in tatai, alShough Pueto diflereoeua іпсошііПШіоп, шіи species has more survivors.

Thus, sn thosecono гошісЬШиу \t^?ipl notcompeiu witoregm'd tu АПсіг ss but fftuusun eMormg, on there ueo so1}/ тРеша toronscea i(rct^ Г^иге [p. tffien the ceucmdround ОєуПш, Swo tionps may tiave occmred m the firsnnoun0.

([(here may be only one variant from one species left that has outcompeted the others, or ohsre may stiilbesnverat ormmts fromdlfferenrsperiea .eft that Mve manaaedtocumdn trie ftiu. Howevoy Шосє was one tr more гррсгєг that made it through ttie fleet oomaU is hualnvadSwithregindIa CPesunand round, as under these circumstances, there will inevitably oeatie organiom leftteaawiilaшvide longer thmiihe The seeonil rouud h aifferenafrom ihe oioi rormd. In itefiesrroun0, Шеге were an nntem^0 omino acid pool, whoreas tht ru waa otti an InieeatO onim arid poti іп the second rosmd. d eacotsin єсєту sina^l^n onrcptism aoP оспЬе Јк^<^^^;се^гГ i^h^o woySt

Theft^t wat li byono oigamsm сошитту шюШгс to tbSim ho mrnno anM [юес1. Triis^ Hitre were too прєсієі ttasumvcdthroughtoeficeSround, ШеусоиИ nutM!. еопІітютАге second round by devouring each other. This may in other circumstances lead to an arm's race, but there are insufficient resources to continue this for long, even among those who manage to survive by devouring others.

Therefore, under these conditions, another way can arise. Regardless of how long they can stretch their metabolism, there are those that will perish before the others, which means their amino acid pool becomes available to the others without them taking it in a hostile way.

Thus, the organisms will be able to survive longer by peacefully absorbing the necromass pool from those who cannot survive as long as themselves. This means that it is possible for members of different species to also survive, not by hostilely devouring others but by peacefully obtaining energy and nutrients from the detritus of organisms that perish by themselves. However, there will still inevitably be one individual left through the first and second rounds, as one must perish before the other.

Strictly speaking, there could be one surviving member of each species left before the last ultimate survivor is unveiled, giving this scenario a 50% probability. However, it is more likely that the organism survived so long because of its physiological constitution, an advantage shared by the clonal colony. Thus, one species possessed an advantage that made it survive longer than the other. Thus, it is not entirely stochastic factors that come into play here. Therefore, the last two survivors are likely to be from the same species, after which one devours the other and only one individual remains.

Thus, selection between taking the amino acid pool hostilely and between taking it peacefully from randomly succumbed organisms will be able to occur.

Thus, the organisms that can stretch the available external and internal resources as long as possible and use them as efficiently as possible are also those that have the greatest opportunity to survive the longest in some spot in the first and second rounds until a new impact sends them to a place with an external amino acid pool. Since they are also the organisms with the greatest opportunity to exist in the greatest numbers, they are also the most likely to send off more members of their species, or only their species.

The third round I: altruism

The environmental pressures discussed in the previous section could potentially lead to the emergence of a remarkable strategy, namely, inclusive fitness or kin altruism. This was described by Hamilton (1963; 1964) in social insects, where one organism helps another to increase its reproductive fitness at the expense of decreasing its own. This strategy has since been shown to also exist in microbial life such as E. coli (Akaizin et al., 1990), where autolysis of part of a starving population occurs, thereby replenishing the amino acid pool for the surviving organisms and, thus, promoting the survival of the rest of their kin.

This is a form of microbial self-awareness, a characteristic of intelligence. For this strategy to occur, a third round is required, where the surviving organisms are selected by being sent back and forth in spots over several rounds.

In new impacts, organisms will be flung away from the impact site in all directions in the form of an expanding circle, and some of the organisms will be able to end up in a new place with an amino acid pool. If the new site possesses a suitable amino acid pool, the organisms that survive being placed there will also be able to build up their numbers strongly again. It has thus been a population that has repeatedly disappeared upon impact and landing and then grew again. Reproduction occurs by binary fission, where the number of microbial life forms increases exponentially, which can be expressed as follows:

where Nn represents the number of organisms at the end of a time interval, N0 represents the initial number of organisms at the beginning of a time interval, and n represents the number of generations. Thus, if there are sufficient amino acids in the new spot, it will only take a single arriving organism 20 reproductive rounds to reach ~1 x 106 organisms.

In the first and second rounds, events proceeded fairly mechanical. While evolutionary adaptations could occur in the first round and acquired or existing preadaptations could play a role in the second round, the prevailing conditions still made the events proceed in a predictable manner.

While the evolutionary adaptations in the arms race in the first round were not entirely predictable, as they could take many different directions, this is irrelevant as the organisms would run out of external resources anyway, and the second round would be decisive as it would take its point of departure in the adaptations that were when resources ran out, and individual members surviving on internal resources would ultimately be left.

The third round occurs fairly mechanically as well. The organisms are mechanically sent back and forth between spots. Only in a few places will a new impact send them off in time for survivors to come along. Those who may remain may be infused with a necromass amino acid pool, as the impact released it from those that perished on impact.

This repeated situation can lead to cooperation between the organisms, where it is important to economize with the resources as much and as efficiently as possible. Thus, rather than organisms in the second round starting a competition against each other, they can also initiate cooperation to give cues by voluntary autolysis (see Figure 2). A cooperation will in the situation be safer, as randomly obtaining the amino acid pool from those who perish will take time and will be very uncertain, as it cannot be determined when and where it occurs.

Hewcver, istCen tie orgamsmc ct^iecq^viqci^te wilh eacVvther cboctwhen them isa neeS to renew ssc amino acid pool, ChiswillreUuce the randomness that prevails in these circumstances, snd tine chmce tv1 suovrsai will inorease ait c renth of ccmmuntcoliov, аціеп is sharacteristie of inteUigence.

This scenario has indeed been observed. Thus, an E. coli population experiencing starvation would gradually split into two subpopulations. One subpopulation eventually perished through autolysis, whereas the other subpopulation utilized the released cellular detritus and continued growing and reproducing (Akaizin et al., 1990). The interesting point here is that in other situations when a population of organisms reproduces, there will be a doubling in number. However, in this situation, the population will both reproduce and yet decrease in number. If this happened over several rounds of being sent back and forth, there could now be adaptations in an arm's race to stretch the metabolism further, as there is now a selection for this in the renewed first round, and cues that this will be needed in the renewed second and third rounds will occur. Thus, association and anticipation, characteristics of intelligence, can now be evolved.

Figure 2. The subsequentsituationinlhefirst Emd second rounds. In the firstround, there sire eodemal resourcesthat one species (green) melees bettes use ofby hevirtgevslved hie strategy ofisolating iirelf fromthe oihes apecisr. Nest to hinthe epccies (chmging coSuurs inyellow) gourd irresutarly m anauc's race . su the secondrosnd,organisms undagoingastofy sis aresren in a eow such that toe olherr in the row liave ruouglv rsreins ecidt to suveiee fo tire neet tow. Altho^hthis scesario resemleleslheone mFiguvv 1, the latter shows stochastic events, while this scenario shows altruistic sacrifice. In reality, there will not be sqm! absaieeire ol cmmoasiCs, asd готе will bekutcrcatimr. When с)^іг^іУ^сГі^п is mcluVed, иріеісс піИ sollowce rcilhmttiu cesurnse (if 11, 1,1, 5,3, l. Crediis: t^i^^l^^^iCi^.1 images were rihtpied from Meinour, 201 1,201e :

The following calculation can illustrate the value of this. It is assumed that there are initially N = 8 x 105 organisms in the same clonal population in the spot. Of those, 4 x 105 will be destroyed or autolyse voluntarily, leaving 4 x 105 organisms. For example, 15% of cellular detritus is used for metabolism, reproduction and growth.

Of course, it is not a reproductiveperpetuum mobile. Thus, even if it is half of the population that sacrifices themselves, there will not be a doubling in reproduction of the other half of the population, as the amino acid pool will diminish over time both because the energy released by an autolysed organism is less than the amount of energy required to build a new organism and because some of the cellular detritus is lost, which, for the sake of the example, is set to 5% for each round.

Therefore, 20% of the detritus is collectively used or lost up to the first round and again after each new round, while 80% of the detritus is reintroduced into the remaining population each time. Thus, the first generational cycle is given by:

Gcycle = P x (1 - r %)n (4)

= 8 x 105 x (1-0.20%)n

= 8 x 105 x (0.80%)'

= 6.4 x 105 organisms,

i.e., after the first round of reproduction, the surviving population has increased to 6.4 x 105 organisms.

When the next subpopulation among them has autolyzed, resulting in 3.2 x 105 surviving organisms, these reproduce. With a 20% loss of the original amino acid pool, they will have increased in number to 5.12 x 105 organisms after the second round and so on. Thus, it will take n = 60 reproductive rounds before ~ 1.23 organisms of the 8 x 105 are left, meaning that the population will be able to last 60 generations solely by the reintroduction of internal resources into the population. The situation is simplified in terms of both the biochemistry involved as well as the physical circumstances, but it is appropriate here.

This self-sacrificial behaviour is, as described by Hamilton, not entirely altruistic because it is aimed at transmitting the individual organisms' own genes. Thus, organisms with a binary mode of reproduction represent virtually ideal clones, and the genes of such microbial organisms are indeed transmitted to the next generation via an alternative carrier in the form of the sibling, not the individual organism per se. Thus, whether an organism reproduces or whether it is its kin that reproduces is not important.

The continuation of the same genes continues in both cases. Thus, a strategy of cooperation and communication, a characteristic of intelligence, will lead to a safer use of the collective internal amino acid pool, thus ensuring a longer collective survival than if the organisms compete against each other (arms race), devouring each other in a hostile manner (arms race), devouring those who perish (chance).

This cooperation does not occur by conscious choice but by natural selection. There will simply be a selection to absorb nourishment from those who randomly die, which implies randomness and a potentially long time between each time the organism autolyses, and for an organism to autolyse at an expected time and place, i.e., other organisms have cues to where and when an amino acid pool is available. There is an intricate connection between the amino acid pool and the gene pool, as an organism ensures that the offspring of its sibling can potentially achieve one more reproductive round in the future by providing its amino acid pool.

In addition, the passage of time has not been taken into account. Thus, how quickly they reproduce and how quickly they metabolize can occur at different rates. Thus, if organisms reproduce slowly and/or metabolize slowly to economize on resources, it applies that even if it were 60 generations, the duration could vary considerably from one scenario to another.

This collaboration can also evolve to further increase the effectiveness of inclusive fitness, since it is important to stretch the available resources as long as possible, while also using them as efficiently as possible. Therefore, saving resources only by lowering the metabolism and reusing the amino acid pool may not be sufficient due to the different situations.

Thus, a collaborative strategy can eventually make stretching the metabolism and reusing the amino acid pool even more effective. Metabolism is the sum of all reactions that occur within the cell and that provide the energy needed for growth and reproduction but also to maintain internal repair after damage. In fact, sublethal injuries may under these conditions have had a higher frequency.1

Thus, selection must initially have ensured that maintenance of the organisms can occur but also that the resources can be used efficiently for as long as possible. The organisms in a clonal population maintain repair of damage, but there comes a point where it is not worthwhile to invest further in repair due to the extent of damage. Thus, rather than invest further in repairing extensive damage, an organism sacrifices itself, saving collective resources, and at the same time releases the amino acid pool for its kin. In this manner, inclusive fitness can be made more efficient.

In addition, as mentioned, the organisms will eventually be able to evolve to communicate with each other about when it is best to initiate this response. This can gradually lead to an extensive coordinated altruistic response in situations not only specifically with injuries but also generally with limited resources affecting the entire population, to which they react in an intelligent communicative manner by many in the population sacrificing themselves for their siblings. Thus, organisms individually increase the amino acid pool to continue the collective gene pool.

Although the self-sacrificial behaviour in the interests of direct kin seems incredible and contradicting classical Darwinian evolution, this altruistic behaviour does not imply conscious self-sacrifice. What changes in evolution are changes in gene frequencies in gene pools over generations. Even fitness is in accordance with this genetic view of evolution, It is also known that bacteria can survive extremely long by entering a dormant state. However, the special circumstances the LHB offered must be kept in mind. Thus, there could be an increased frequency of injuries in these circumstances, and a reproductive lifestyle may have been the better option. whereby the genes programming autolysis for the sake of survival of the kin spread as a result of natural selection, provided that it contributes to the survival of the microbial population. Here, natural selection occurs due to the circumstances described thus far in the LHB.

The third round II: cooperation

The environmental pressures discussed in the previous section could lead to inclusive fitness potentially arising in the form of organisms adapting to acquire energy and nutrients from cellular detritus from those that voluntarily autolysed. As reviewed, there will be pressure to stretch the available resources as long as possible, but there will also be pressure to evolve adaptations to use the available resources as efficiently as possible.

Thus, it applies that voluntarily giving one's amino acid pool to one's siblings only has maximum benefit when it is one's siblings, and not unrelated members from the competing species, who benefit from this sacrifice. This is the essence of Hamilton's rule (Hamilton, 1964). In the calculation example reviewed in the previous section, 5% of the necromass amino acid pool was wasted. While part of this is due to an unavoidable waste resulting from the circumstances, this could also be partly because, although it is organisms from the same colony here, there is a possibility that the chunk of material that landed with them also contained members from other species or that there were other species where they landed. Thus, members of other species had the opportunity to take some of the available cellular detritus and thus contribute to the 5% disappearing from the population.

As a response to this, the cooperative strategy will evolve further to ensure the most effective recycling of the necromass pool. Through the cooperative strategy in the form of taking up the amino acid pool from its siblings and developing it to give and perceive cues for when this happened, there was already a pressure to evolve. Thus, this could evolve further such that members of the same species can recognize each other and gather together, thus actively isolating themselves from other species, which again is a characteristic of self-awareness (see Figure 2). This isolation strategy evolves from both their collaboration on the internal amino acid pool as well as the external amino acid pool. The rounds will occur repeatedly when new impacts send them to a new spot.

First, when organisms land in a new spot with an external amino acid pool, reproduction will again occur. Organisms are already automatically collected as a necessary side consequence of other features. Thus, in clonal organisms such as bacteria and archaea, the organism will divide into two, and the two into four etc. Thus, a colony of siblings always begins at one point due to reproductive constraints and spreads from that one point.

Second, it applies that a selection of organisms had occurred, which could eventually yield cues as to when autolysis occurs, could read cues as to when it happened, could initiate autolysis at `agreed' times, and could be ready when this happened.

Thus, after having gone through the third round several times and evolving an altruism strategy, the scenario in the first round will eventually play out differently. When the organisms in the clonal colony are launched again, they may land in a place where there is another species, but rather than the organisms mixing arbitrarily and competing against each other, making adaptations in an arm's race, the organisms in the arriving colony will bring the adaptations for cues that remove the randomness that prevailed in random scattered autolysis regarding where and when they can take up the amino acid pool. The members therefore do not have to move far to gain access to the amino acid pool when there are cues about autolysis in progress. There will thus be a shorter time between release and uptake of the amino acid pool, and as much as possible can be harvested from the necromass pool.

Thus, the scenario in the first round as it occurred the first time will not happen again. Not only have the organisms evolved a strategy to perform better and more efficiently in the second round, but that strategy also leads to a strategy to perform better in the renewed first round. If this is the first time for one particular species, the arriving organisms will have an advantage over them. They are adapted to handle the situation that will inevitably occur in the next round, while the other species is in a race to be fit at the present time; they are essentially gluttonous with the resources. Thus, the isolationist species may be the only ones to reach the second round; they are naturally selected in that manner.

However, as time goes by with many repeated impacts, both species will have evolved these strategies, and both species will isolate themselves from each other, focusing on utilizing the external and internal resources most efficiently to get through the rounds. Even if there are no other organisms where they land, the isolation strategy will still evolve, as the members do not have to move far to gain access to the amino acid pool when there are cues about autolysis in progress.

Thus, gradually, the first round will transition from being a short-term and costly arms race to a long-term isolationist scenario, just as the second round gradually transitioned from being stochastic events to being an evolved strategy. Thus, the impacting dynamics are still the same; in fact, the situation with suitable spots may eventually worsen, but the evolutionary strategy improves and ensures that the organisms can cope for a longer time.

Cooperation among microbial organisms can arise for several different reasons and occur in several forms, for example, swarming motility, collective repairing of holes in biofilm, collective capture of food, collective aggression etc. (Westerhoff et al., 2014). Their cooperation on the internal amino acid pool can also eventually affect their cooperation on the external amino acid pool. Since a new impact can send them to a place with an external amino acid pool available, the cooperative strategy can further evolve to also cooperating in utilizing these resources as best as possible rather than a new competition arising between them.

Thus, a collaboration to find an external amino acid pool could occur.

A cooperative effort to isolate themselves will also maximize the use of the internal amino acid pool, as they physically avoid the presence of other species among them and thus prevent others from gaining access to their collective amino acid pool.

However, eventually, two groups that isolate themselves from each other can also start an arms race against each other to gain access to each other's resources, even if the cost may be higher than the benefit. They can mount a common defence against other species that either seek to devour individuals from their colony or gain access to resources they have collected themselves. Such a common defence against other species can arise quickly, as they obtain not only the amino acid pool but also occasionally the gene pool from those who sacrifice themselves. Thus, if a variant obtains a defence against the other species, this trait can be taken up and distributed by its kin, and a selection in which they quickly manage an arms race occurs. Here, there is also an arms race, not between members of the same species but between species, where one species gradually achieves less cost through their cooperation on a common defence and can thus be selected for further survival.

Among these cooperation strategies, a further strategy could potentially arise. As reviewed, it has been observed that bacteria have their own version of inclusive fitness, where some sacrifice their amino acid pool so that the gene pool of their siblings can continue. However, a hypothesis could be made that it could also be possible under certain circumstances for microbial organisms to display the classic inclusive fitness seen in social insects, where they actually refrain from reproducing themselves and instead dedicate themselves to assisting their siblings with survival and reproduction.