Where and how did life begin?
Can/could there be a universe without life? Life without a universe? Contemporary science says yes to the first question and no to the second, whereas most religions tend towards the opposite point of view; indeed disagreement on the subject is perhaps the main bone of contention between the two camps. Given that there is such a thing as life, and that we know how to recognize it when and where it exists (no easy task), where did it start? For Galileo and Newton, there was only one place where it could possibly start, the Earth. And, as to how and why it began in the first place, few if any of the ‘classical’ physicists troubled themselves about the question since they were all believers, if not in Christ at least in God. The paradigm of a unique universe created once and for all by an omnipotent intelligence, and henceforth forced to obey rules laid down by this intelligence, served physics and mechanics well for several centuries. But it was not clear how ‘life’, especially human life, could be fitted into this schema which is probably the reason why Newton, having sorted out the physical side of things, tried his hand at alchemy. One can (perhaps) reduce biology, the life science, to chemistry but not to mechanics and in Newton’s day chemistry scarcely existed.
Darwin was extremely reticent on the subject of the origins of life though he did famously speak of “a warm little pond with all sorts of ammonia and phosphoric salts present”, a place where “a protein compound was chemically formed ready to undergo still more complex changes”. This shows that Darwin was at least firmly committed to the idea that life developed ‘spontaneously’ without the need for supernatural intervention or planning. Eventually, in the nineteen-fifties, Miller caused a sensation by simulating in a test-tube the Earth’s supposed early environment (water, ammonia, methane and carbon dioxide) and bombarding it with ultra-violet radiation. The result was the spontaneous formation of certain compounds, including amino-acids, the building blocks of proteins. However, it would seem that Miller and Urey got the composition of the early Earth’s environment wrong and there are other reasons why the Miller/Urey experiment is no longer considered to be a good indication of how life on Earth started. Since the discovery in the nineteen-seventies of sulphur consuming microbes in deep ocean hydro-thermal vents, and the copious eco-systems to which they give rise, the theory that life began under the surface of the Earth, rather than on it, has become more and more popular. Such bacteria do not require sunlight to produce energy, i.e. do not photosynthesize, and, because of their location, they would have been at least partially protected against the intense bombardment of the Earth’s surface by meteorites which was so characteristic of the early years of the Earth’s history.
Life from elsewhere
There is, however, another way to explain the sudden appearance of primitive life on Earth about 3.85 billion years ago : it came from somewhere else in the universe. The idea that there might well be life outside the Earth goes back as far as the IVth century B.C. and demonstrates how astonishingly ‘modern’ many of the Greek thinkers were in their outlook. Although better known for his contention that the goal of human life is, and should be, pleasure, Epicurus also wrote extensively on physical matters. Unfortunately these works have been lost and are only known via his Roman follower, Lucretius, author of the long poem De Rerum Naturae. The latter writes
“If atom stocks are inexhaustible Greater than the power of living things to count, If Nature’s same creative power were present too To throw the atoms into unions — exactly as united now Why then confess you must That other worlds exist in other regions of the sky And different tribes of men, and different kinds of beasts.”
Note that this is a reasoned argument based on the premises that (1) there exists an abundant supply of the building-blocks of life (atoms), (2) these building-blocks combine together in much the same way everywhere, and (3) Nature’s ‘creative power’ (‘energy’) is limitless. Therefore, there must exist other habitable worlds containing beings made of the same material as us but different from us. This is almost word for word the argument put forward by contemporary physicists that we are not alone in the universe. Lucretius does not go so far as to suggest that there could be, or ever had been, any interaction between these different ‘worlds’. However, the Gnostics (‘Knowers’, ‘Those who Know’), a half-pagan, half-Christian sect that flourished during the declining Roman Empire, taught that human kind did not originate here but came from what we would call ‘outer space’ — indeed this is precisely what they knew and what ordinary persons didn’t (Note 1).
Panspermia
The belief that life did not begin here but was brought from elsewhere in the cosmos seems to have disappeared after the triumph of orthodox Christianity but eventually re-surfaced at the end of the nineteenth century in a place where one would not normally expect to find it, namely physical science. The 19th century German physicist von Helmholtz, a hard-nosed physicist if ever there was one, wrote in 1874: “…it appears to me a fully correct scientific procedure to raise the question whether life is not as old as matter itself and whether seeds have not been carried from one planet to another and have developed everywhere that they have found fertile soil.” (Note 2) Lord Kelvin agreed, arguing that collisions could easily transport material around the solar system and thus ‘infect’ other planets with life, as he put it. And the Swedish chemist, Svante Arrhenius, energetically took up the idea which he dubbed ‘Panspermia’ (‘seeds everywhere’). Nearer our own time, Francis Crick of DNA fame argues in his book Life Itself, Its Origin and Nature that “microorganisms ….. travelled at the head of an [unmanned] spaceship sent to Earth by a higher civilization which had developed elsewhere billions of years ago.”
Life as a Cosmic Phenomenon
But the theory that life came from outer space is above all associated with the work of Fred Hoyle and Chandra Wickramasinghe who have expounded it in great detail in a series of books and scientific papers. They summarize their position thus : “The essential biochemical requirements of life exist in very large quantities within the dense interstellar clouds of gas. This material [eventually] becomes deposited within the solar system, first in comet-type bodies, and then in the collisions of such bodies with the Earth. (…) The picture is of a vast quantity of the right kind of molecules looking for suitable homes, and of there being very many suitable homes [i.e. planets].” (Note 3)
As the two authors never tire of pointing out, ‘Panspermia’ is not just another scientific theory : it constitutes a paradigm shift only to be compared with the shift from a geocentric to a heliocentric viewpoint instigated by Copernicus. Just as humanity previously — and mistakenly — considered itself to be situated at the centre of the universe and the favoured creation of the Almighty, so biologists and astronomers today mistakenly tend to take it for granted that the Earth has been particularly favoured to be the unique seat of intelligent life. In its full development, as propounded in Hoyle’s The Intelligent Universe (the title says all), the theory of ‘panspermia’ really means what it says : ‘seeds of life evrywhere’. Hoyle and Wickramasinghe argue that life is so improbable an eventuality, requiring so much fine-tuning of physical constants, that it has either always existed (Hoyle’s preferred option) or has only come about once. A complicated circulation system, involving interstellar dust, comets and meteorites, is responsible for randomly disseminating the seeds of life throughout the universe in the expectation that at least one or two of them will fall on fertile ground somewhere sometime. As one might expect, the Hoyle/Wickramasinghe theory was, and is, highly controversial. In the past they would have run foul of the Inquisition — Giordano Bruno was burnt at the stake for propounding something vaguely similar — but, this being the 20th century, their main opponents have come from within the scientific establishment. The two scientists, despite their impressive credentials, were met with what Hoyle describes euphemistically as “a wall of silence”. It is even said that Hoyle’s outspoken advocacy of ‘panspermia’ is the main reason he was not granted the Nobel Prize for his seminal work on the carbon cycle in stars.
Evidence in favour of the Hoyle/Wickramasinghe Theory
We require a new scientific theory to, (1) explain known data in a more elegant and satisfactory way than current theories and (2) make predictions which can be tested experimentally. Now the Hoyle/Wickramasinghe theory certainly does explain something that contemporary astro-physics struggles to make any sense of, namely the surprisingly early appearance of bacterial life on the Earth. The Earth is currently considered to have formed some 4.6 billion years ago but for most, if not all, of the first seven or eight million years it must have been a boiling inferno uninhabitable even for heat-loving microbes. However, the high level of carbon-12 in certain rocks that date back 3.85 billion years, suggests that microbial life already existed at that early date. We are not here talking about organic molecules but about unicellular organisms which, though ‘primitive’ compared to plants and mammals, possess DNA (or RNA). It is scarcely credible that the transition from a few diffuse chemicals to such a highly organized entity as a prokaryotic cell came about in such a short time in evolutionary terms, especially since the subsequent transition from bacterial to multicellular life took around 3 billion years! But for Hoyle and Wickramasinghe, this is not a problem : primitive life arrived here ready-made, a seed quite literally falling from the sky either naked or enclosed in the remnants of a comet that, like Icarus, had ventured too near the Sun and had spilled its contents into the atmosphere (Note 4). So, is there any evidence that a microbial spore could exist in interstellar space and be wafted to Earth riding on a gas cloud or enclosed in the kernel of a wandering comet? In the seventies, when Hoyle and Wickramasinghe first advanced the general idea, it sounded more like science fiction than science — Hoyle was after all the author of a successful SF novel The Black Cloud. But since then the critics have had to eat their words — though in point of fact scientists never seem to actually bring themselves to do such a terrible thing — since it is now common knowledge that interstellar dust is full of molecules, many of them organic, and that comets contain most, and probably all, of the basic ingredients for life. “Analysis of the dust grains streaming from the head [of Halley’s comet] revealed that as much as one third was organic material. Common substances such as benzene, methanol, and acetic acid were detected, as well as some of the building blocks of nucleic acids. If Halley is anything to go by, then comets could easily have supplied Earth with enough carbon to make the entire biosphere.” Davies, The Origin of Life, p. 136
It is also generally admitted now that there is a considerable exchange of (not necessarily organic) material throughout the galaxy : the very latest issue of Science (15 August 2014) contains an article “Evidence for interstellar origin of seven dust particles collected by the Stardust space craft”. So far, so good. But all this, of course, stops well short of Hoyle and Wickramasinghe’s claim that actual bacterial spores and/or viruses can and do make the perilous journey from a cloud of interstellar dust to a comet in the Oort Cloud and then on to the interior of the solar system and us. A number of claims for the presence of fossilized organic material in meteorites have nonetheless been made, for example by Claus and Nagy in the 1960s and, more recently, by two researchers from the University of Naples D’Argenio and Geraci who concluded that their results constituted “clear evidence for the existence of extra-terrestrial life”. Those who wish to pursue the topic further are referred to a recent article by Chandra Wickramasinghe on DNA Sequencing and Predictions of the Cosmic theory of Life (and the extensive bibliography at the end). This is available free of charge at http://arxiv.org/ftp/arxiv/papers/1208/1208.5035.pdf
Can bacteria and viruses reach the surface of the Earth?
The suggestion that diseases can come from space follows on from Hoyle and Wickramasinghe’s belief that life came from space in the first place. For the cosmic bombardment continues unabated though, thankfully, on a lesser scale than during the first billion or so years of the Earth’s history. Suppose for the moment that a certain amount of interstellar ‘dust’, some of it organic, finds its way into a comet inhabiting the so-called Oort Cloud situated beyond the orbit of Pluto. Incredibly, there are an estimated billion or more such comets on highly eccentric orbits and a few enter the inner reaches of the solar system each year. Near the Sun much of the comet melts, ejecting millions of tons of incandescent debris into space and the Earth, like the other planets, cannot avoid ploughing through this cosmic muck. So much is fact. But can any organic material make it to ground level without being burned up or crushed ? If the answer is no, there is no point in discussing the diseases from space theory. However, it seems that bacteria and viruses, especially if protected by some sort of coating, can enter the Earth’s atmosphere without burning up if they come in at an oblique angle. H & W have calculated that “to fit the heating requirement, according to our criteria bacteria are about as big as they can possibly be”. If a bacterium exceeds 1 micron in length it must, according to H & W, be rod-shaped, i.e. what we term a ‘bacillus’. (Yersinia pestis is rod-shaped incidentally). Small particles will be wafted this way and that by air currents or descend inside raindrops or snowflakes. Have any micro-organisms of suspected cometary origin been identified? This is difficult to establish since there is always the possibility of terrestrial contamination but high resistance to ultra-violet radiation would suggest an extra-terrestrial origin. Again various claims have been made, for example by Wainwright, Shivaji et al. and one new bacterial species culled from the stratosphere has even been named Janibacter hoylei.sp.nov. !
Tell-tale signs of cosmic origin
What characteristics of epidemics/pandemics does official epidemiology have difficulty in explaining? Or, to put things the other way round, supposing for a moment that pathogens can and do arrive from outer space, what special features would we expect to find in the consequent epidemics ? Basically, the following : 1. We would expect an epidemic/pandemic with an extra-terrestrial origin to be unusually severe because the immune systems of potential hosts would be taken unawares; 2. We would expect very rapid spread since the pathogens would not originally be dependent on human or animal vectors (would rain down on people from the air); 3. We would expect a very wide but somewhat patchy distribution since the pathogens would be taken here and there by air currents; 4. We would expect the attack to be ‘one-off” since only after several outbreaks would a new disease be able to establish itself with a permanent terrestrial focus − to begin with it would most likely be too lethal and kill off potential hosts.
So, are there any epidemics or pandemics that fit the bill? Yes, I can think of several candidates at once, the Vth century Plague of Athens (1, 2 and 4); the Plague of Justinian (1, 2, 3 and 4); the ‘Sweats’ of the Reformation period (1, 2 and 4); and the 1917-18 outbreak of Spanish Flu (1, 2, 3 and 4). Unfortunately, almost all outbreaks of disease prior to the 19th century are poorly documented so this only leaves the 1917-18 Spanish Flu Pandemic on which H & W concentrate in their book (along with the Common Cold). Since the Spanish Flu killed rather more people than WWI worldwide − estimates vary from 26 million to 50 million deaths − there is no doubt about (1), the severity. Also, because the influenza virus is constantly mutating, it generally manages to keep ahead of the human immune system : each wave of infection is thus essentially new even if given the same general name. So Spanish Flu passes on 4, and also qualifies on 2 and 3. . However, Spanish flu had the benefits of (from its point of view) modern transportation systems and is known to have been passed on by person to person contact (especially by sneezing). However, “The lethal second wave [of Spanish Flu] involved almost the entire world over a very short space of time…. Its epidemiological behaviour was most unusual. Although person-to-person spread occurred in local areas, the disease appeared on the same day in widely separated parts of the world on the one hand, but took days to weeks to spread over relatively short distances. It was detected in Boston and Bombay on the same day, but took three weeks to reach New York City, despite the fact there was considerable travel between the two cities….” Who wrote the above − Hoyle and Wickramasinghe? In fact, not. The author is a certain Dr. Louis Weinstein cited by H & W and presumably a contemporaryof the pandemic. Likewise, H & W cite Professor Magrassi commenting on the 1948 influenza epidemic “We were able to verify….the appearance of influenza in shepherds who were living for a long time alone, in solitary open country far from any inhabited centre; this occurred absolutely contemporaneously with the appearance of influenza in the nearest inhabited centre”. It is on the basis of this kind of evidence, along with detailed maps showing the spread and distribution, that H & W make their case for extra-terrestrial origin. But everything they say about the Spanish Flu pandemic a fortiori applies to the best candidate of the lot, at least on counts (1, 2 and 3), namely the Black Death itself.
Did the Black Death come from Space?
H & W only devote five pages of their well-documented book to the Black Death and the treatment is sketchy indeed. When H & W were writing (late nineteen-seventies) the official view was that the Black Death was undoubtedly bubonic plague and that it was spread about by rats : even so learned an author as Shrewsbury does not for a moment question the received wisdom though he does state that the quantity of rats required to get such a pandemic going would be enormous. H & W also assume that the Plague of Justinian and the Black Death were caused by the same pathogen, an assumption Dr Twigg and others have questioned. H & W do, however make one or two valid points. They rightly ridicule the idea of an army of rats advancing like killer ants across most of Europe infecting all and sundry as they march. But, still keeping within the rat/bubonic plague schema, they point out that, if the pestilence was spread about by ship, at least to begin with, we would expect it to systematically spread inland from seaports, something they claim is not the case if we examine the evidence. For example, they cite the testimony of Carbonell, archivist to the Court of Aragon, who reports that the Black Death “began in Aragon, not at the Mediterranean coast or at the eastern frontier, but in the western inland city of Ternel.” However, we have to distinguish between evidence that the Black Death was propagated by air (which I certainly believe) from the belief that it came from outer space in the first place. H & W emphasize the very extensive but strangely patchy distribution of Black Death mortality: while it attained remote hamlets and monasteries it spared Milan and Nuremburg almost completely. But again this is evidence for airborne dissemination rather than proof of extra-terrestrial origin. Dr Twigg has also pointed out to me that a vast quantity of bacteria would be required to start the pandemic going in the manner H & W suggest. The Japanese experimented with bubonic plague as a biological weapon and dropped 36 kilos of bubonic plague infested fleas. Seemingly only 7,000 humans died, a statistic that was acquired fifty years later and so was more likely to have been amplified than reduced. Serious though this must have been for the unwilling recipients of this Japanese manna from heaven, this is not a fantastic death toll. And one would expect dropping infected fleas to be a more efficient method of spreading the disease than simply having bacteria drifting down spasmodically.
Conclusion that there is no conclusion
So where does that leave us? As far as I am concerned, I would say that Hoyle and Wickramasinghe have made a fair case for the Black Death coming from outer space given the extreme severity, rapid spread and extended but patchy distribution of the pandemic, the worst in human history. As to (4), whether the Black Death was a ‘one-off’ outbreak that failed to establish itself or not, this depends on whether one considers that subsequent outbreaks during succeeding centuries were, or were not, the same disease. The jury is not out on this topic and both sides have made valid points. But there is no doubt that ‘plague’, whatever it was, suddenly and mysteriously disappeared from Europe in the early eighteenth century never to return apart from a few spasmodic 20th century cases. But I am not sure that a supposed extra-terrestrial origin has any particular bearing on this circumstance.
More specifically, I do not feel that H & W have said anything to shake my personal conviction that the Black Death was not bubonic plague. If the Black Death was plague and came from space, this suggests that the pandemic started off as the pneumonic variety since human beings would absorb it directly from the air, or from fresh water. It would subsequently pass from human beings to rats and the bubonic variety would dominate and the ‘normal’ scenario develop from then on. Now, an initial outbreak of bubonic plague amongst rodents can spread to humans and become a predominantly pneumonic outbreak, since this is what happened in Manchuria in 1910, but I do not know of any cases of an initial pneumonic epidemic giving rise to bubonic plague. Moreover, supposing for the moment the Black Death was plague, it is not possible that the outbreak was exclusively pneumonic since buboes do not have time to form and we have plenty of contemporary medieval descriptions of buboes, whatever it was that caused them. H & W’s suggestion that plague came from above does not help us to understand the spread of the 14th century pandemic, rather the reverse. It may well be that the cause of the Black Death, whatever it was, did come from space but this does not advance us in understanding what the disease was and how it propagated. Although H & W’s books have made me a likely convert to the general theory of panspermia, I do not feel they have brought us any closer to understanding the Black Death which remains as much of an enigma as ever. SH 12/10/14
Note 1 According to the Gnostics, the universe was not deliberately created by an omnipotent God but was the result of a cosmic accident with tragic consequences, i.e. was the result of Chance rather than Necessity. They identify God with ‘the Light’ and, in one version, relate how Sophia, the ancestress of humanity, ‘fell’ from a domain of light into a dark, cold and empty universe. Some ‘seeds of light’ end up on the Earth which is ringed by hostile powers (archons) who prevent those who have become aware of their true nature from returning to their place of birth. This schema is really quite close to what we, and especially H & W, currently believe to be the case. It would seem that all the heavier elements including carbon and oxygen were created by nuclear fusion in the heart of stars and were subsequently disseminated throughout the universe in a supernova explosion. Any material ejected would certainly have found itself in a cold, dark and hostile world. Also, since our bodies are made of carbon, hydrogen and oxygen, we are indeed “stardust”. And if Hoyle and Wickramasinghe are right and the first organisms formed in space, we are aliens or the progeny of aliens since the Earth is not humanity’s place of birth.
Note 2 Quoted by Paul Davies in The Origin of Life (p. 125)
Note 3 From Hoyle & Wickramasinghe, Life Cloud (1978). The original schema given in this book and Diseases from Space (1979) goes something like this :
(1) The cycle starts with outflows of gaseous material from the surfaces of stars;
(2) High-density clouds give rise to ‘dust’, “solid particles with dimensions comparable to the wavelength of visible light”(H & W)
(3) Under compression, organic molecules present in the gas clouds “condense in solid form onto the dust grains” (H & W);
(4) In particular formaldehyde (H2CO), which is “one of the commonest organic molecules actually found by actual observation in interstellar space” condenses onto grains and a process of polymerization is induced by cosmic rays;
(5) Sugars and polysaccharides form — and “it has been shown by C. Ponnamperuma that this can happen when formaldehyde is exposed to ultra-violet radiation”;
(6) All of the basic building blocks of life are formed in a similar way and are transported randomly around the galaxy by comets;
(7) Primitive living organisms evolve inside some comets;
(8) One or two comets are drawn within the inner solar system and, on partially melting, deposit clouds of living material some of which falls onto the Earth.
Wickramasinghe has subsequently extended this model to one where “the genetic products of evolution on a planet like the Earth were mixed on a galactic scale with products of local evolution on other planets elsewhere” (from the paper on DNA sequencing mentioned earlier).
Note 4 At first sight it might seem that Hoyle and Wickramasinghe have not answered the problem of the origins of life but have simply shelved it by situating it somewhere else. Their reply would be that, firstly, rather more suitable environments for the development of life than the early Earth have certainly existed, and, secondly, given the vast number of galaxies and the age of the universe (between 14 and 15 billion years) even such an improbable event as the emergence of microbial life might conceivably have occurred (and apparently did). The point is that, given the cosmic circulation system they propose, life need only occur once somewhere for it to eventually reach practically everywhere (though it would of course not catch on equally well everywhere). And this is assuming the Big Bang scenario. If we assume Hoyle’s modified Steady State model, life has always existed and always will.
Sebastian Hayes 