This short story of a very long time is an attempt to encapsulate the knowledge that this inquisitiveness has gleaned from the evidence that nature has left us.

Although we can read and enjoy hundreds of pages of detailed text on each of the myriad of components of the very long history of the present day, there is some key evidence and deduction about our genesis that can be satisfyingly complete yet compact.

Such a (very brief) history of everything can then more easily stay with us and remind us constantly of how significant we all are in the universal scale of things, how vulnerable we are, how bound up we are with what surrounds us and how we should cherish the resources we have literally at our disposal.  hide this.

Firstly, the spectrum (colour mix) of light reaching us from stars in other galaxies (massive clusters of stars) is ‘red-shifted’, i.e. the bands of light (radiation) emitted are shifted in frequency and wavelength in the same direction that red light is different from blue light. This is the light equivalent of the Doppler effect, that explains, for instance, the lower pitch (frequency) of sound from objectives moving away from us (like when a train, racing car or motorbike has gone by). This ‘red-shifted’ light tells us that, on average, galaxies are moving apart. The logical conclusion is that if we imagine going back in time, i.e. we wind the universe back, then the galaxies become closer and closer together until at some time they are pretty much all in one place. Also, because it takes light a long time to reach us from far away galaxies we are in effect looking far back in time when we look at the light from them. These two deductions are down to the astronomer Edwin Hubble, after whom one of the best satellite-based telescopes is named.

From these deductions put together it was further deduced that not only would the early universe have been very hot and radiating intensely (all that mass and energy close together) but also that there should be some evidence of this in the form of very, very red-shifted radiation (in the microwave spectrum) coming from the most distant detectable parts of the universe. This very, very red-shifted (microwave) ‘background’ radiation (very much at the expected temperature) was indeed discovered (by the two physicists Arno Penzias and Robert Wilson in 1965). It has been thought of as a very distant echo of the Big Bang.

A bit of a problem with this Big Bang evidence arose because the ‘background’ radiation was so even that it didn’t seem to allow for matter to have clumped together to create the clusters of galaxies we know are out there (and all the other clumps of stuff in the universe). Inflation, and other theories to explain this, suggested there ought to be, and indeed needed to be, ripples in the ‘background’ radiation. Then, in 1992, a satellite named COBE (for Cosmic Background Explorer) discovered these very ripples.

A further problem with the Big Bang was that radioactive dating of the earth suggested it was about 4.5 billion years old whereas winding the universe back gave an age of at most about 2 billion years for the whole universe. Corrections to the winding back methodology brought these ages in line but other problems arose. For instance, there appeared to be stars around that were about 20 billion years old.

Fortunately for Big Bang theory, these problems are now resolved and we have the birth of the universe (and time as we know it, too) happening just under 14 billion years ago with the oldest stars 1 billion years younger.

A key further question was of course where all the matter we see came from. However, this was relatively easily answered. First of all, matter (in the form of particles and anti-particles) is interchangeable with energy. Albert Einstein’s famous E=mc2 (energy equals mass times the square of the speed of light) equation tells us how. And atomic bombs have been perhaps the most vivid realisation of at least the reverse process (matter into energy). Where energy comes from is not a problem either because the positive energy in matter is balanced by the negative energy in gravitation – i.e. it adds up to zero. And theory (by the physicist and mathematician Paul Dirac) that anti-particles should exist has been validated as scientists can now readily create them.

Finally, there is the big question of what triggered the Big Bang. A big problem with the early universe is that it is so opaque, obscured by its own brightness, that we can’t see back into that early stage let alone before it. We may however, sometime, be able to see beyond the opaque early stages by detecting and analysing gravitational waves. For now though, we can only devise unprovable theories. This leaves us with ideas like colliding matterless and energyless universes (so that the Big Bang was just a relatively dramatic stage in a longer birth), a rebounding collapsed universe, a rebounding collapsed star, perhaps a black hole, or colliding branes (brane as in membrane). The later Epilogue touches on these further.

Where then does this leave us? Well, the broad elements of the idea of a Big Bang are widely agreed by scientists. However, and needless to say, there are some scientists (never mind creationists) with concerns or objections to this and other parts of this story.  hide this.

There is a particular reason for this reference to a few 100 billion stars worth of matter. Stars (and what they can heat up around them) are what we can see and we have a good understanding of their evolution, thanks in part to the invention by the two astronomers Ejnar Hertzsprung and Henry Russell of ‘H-R diagrams’ which can beautifully map the lives of stars because they are born, live through various stages and die – some spectacularly (e.g. in supernova explosions) and some just by fading away.

The astrophysicist James Jeans had importantly identified that if enough matter is squashed together at one time then the contracting force of gravity overcomes the expanding force of gas pressure so that it continues to shrink.

If we put the above thinking together we can understand why it is that bright blue stars, which are young ones, tend to be where there are still high concentrations of gas or clouds and therefore tend to be born together in big litters. Thus, these clouds, like the Orion Nebula, are the birthplaces of stars.

Back then to the bigger things such as our few 100 million stars worth of spinning breakaway matter. It seems that in this early stage of our galaxy its shape was roughly spherical or globular. The oldest stars in our galaxy seem to be spread out in this spherical or globular shape.

Gradually, however, it seems that the spinning sphere of matter flattened out into more of a lens that flattened further into a disc. Newer stars (with heavier elements in them collected from explosions of earlier, bigger stars) lie in the lens shape and the youngest stars are found in a thin disc where there is still gas present for stars to be born. This is the disc we see a side view of across the sky – the Milky Way.

We also know that the Milky Way has spiral arms, one of which we sit within (for now). As ‘for now’ implies, the matter in spiral arms (stars and gas) is matter that is rotating around the centre of the galaxy but bunches temporarily in these arm like structures. The greater density of gas in these spiral arms then triggers the birth of stars that are of course young bright stars that exaggerate the appearance of the arms.

It seems likely that the birth of our star may have been triggered in this way. Larger stars triggered into life at the same time will have burnt out and smaller ones were never very bright anyway. Those around our size, triggered at the same time, have drifted out of sight as the spiral arms stretched out. This is why the nearest stars to us are so far away.  hide this.

The orbits of planets in the Solar System are pretty much in the same plane (the nearest to and furthest from the Sun being exceptions somewhat). These orbits are also nearly circular (expect for Mercury and Pluto again) and also fairly evenly spaced with the planets all going the same way round the Sun.

Other characteristics of planets seem to relate to their size and distance from the Sun. Close-in planets are small, dense and slowly rotating with little or no atmosphere, and few or no satellites. Middle orbit planets are large, with low density, fast rotation, an atmosphere and many satellites. Remote planets are just icy.

The Protoplanet Hypothesis (a version of the Nebula Hypothesis), attributed in particular to the physicist Carl-Friedrich von Weizsacker, best explains how the Solar System was created in the light of this evidence around us. It goes like this. Just as our galaxy, the Milky Way, started with a large lump of matter (with a bit of spin) breaking away from the turbulent clouds of the early universe, so our Solar System can be seen to begin perhaps about 5 billion years ago with a fragment of mainly hydrogen and helium and a lot of spin, breaking away from a larger interstellar cloud.

Gravity then caused the fragment’s centre, being a bit denser, to collapse relatively rapidly. As it contracted, it started to rotate more rapidly (again like an ice-skater drawing in his or her arms).

The remainder of the fragment, flattening into a disk (again like in the formation of our galaxy), began to clump together into particles that grew into larger and larger bodies and eventually into the planets. Stages of such a process have been seen around other stars.

The increasingly hot central Sun would have ‘blown away’ anything other than the rocky matter, forming, the close-in planets, while outer planets are icier. This effect is seen at a smaller scale again in the relationship between once much hotter Jupiter and its moons.

It seemed at first that the Earth and Moon (with similar ages and chemical composition) were two close objects becoming a double planet system, just as there are double star systems. However, it is widely accepted now that the Moon was knocked out of the Earth as a result of Earth’s early collision with a Mars sized lump of matter.

Not much in the way of problems remains with the Protoplanet Hypothesis. There is a bit of difficulty with whether there has been enough time for dust to collect together to make the planets because for small amounts of matter, gravity is not very strong. However, various possibilities (electrostatics, stickiness and short range gravity) might well have done the trick. The one big problem of how the Solar System’s angular momentum, (a combination of the mass of matter and its circular motion) originally mainly in the Sun, became almost entirely concentrated in the planets seems to be resolved by the Sun’s magnetic and gravitational fields acting as a brake on the Sun’s rotation and as a means of transferring the momentum to the planets.  hide this.

Four billion years ago was still a pretty violent time with thousands of meteorites bringing important elements (if not more complex chemicals) to the raw materials resource on earth. These meteorites were not burning up on the way – evidence suggests a very limited atmosphere, with almost no oxygen, poisonous for most present life forms and probably racked by raging storms.

Water was around very early on, evidenced by sedimentary rocks (worn down earlier rocks) nearly 4 billion years old. Carbon dioxide and monoxide, cyanides and phosphates were also present – all important bits of life’s construction. Together, such chemicals provide for the energy creating reactions essential for life.

Lightning striking mixtures of fairly basic chemicals is known to be able to produce complex organic chemicals such as amino-acids – the building blocks of the like of DNA which in turn are the building blocks of life. Two chemists, Stanley Miller and Harold Urey, showed this back in the 1950s.

Other factors of possible importance to the origin of life are inorganic clays whose sheets of atoms may have been the reaction chambers for the production of more complex molecules.

The origin of skins, needed to separate living from inert material, may relate to the known natural creation of skins by hydrocarbons present on the early earth.

An extraordinary feature of this complex genesis is that, although everything was there for it to happen, it seems to have been a distinctly lucky actual event. Genetic analysis suggests it happened only once (on Earth) and all life that we know of has evolved from it.

In what environment this extraordinary event may have occurred, if it occurred on Earth, is hinted at by the heat-loving sulphur-eating, methane-brewing habits of some particular bacteria whose genetic makeup suggests they are the earliest in the tree of life. Interestingly most of them are anaerobes, i.e. they require the oxygen-lacking environment found on the early Earth. They thrive today around the various forms of vents from the Earth’s core, including the hot springs on our ocean’s floors known as ‘black smokers’.

Having identified the potential for life to have begun on Earth from the construction of more and more complex composites of chemicals, the fact that it seems to have been a one off occurrence suggests a low probability for its occurrence and therefore, to some, a greater likelihood for life to have begun elsewhere (much more time for it), perhaps in interstellar clouds where increasingly complex organic chemicals have been found to exist and which have been around for a very long time.

Wherever it did happen, for the Universe has been described as a warehouse of life’s spare parts, the oldest fossils on Earth have been found in three and a half billion year old rocks in South Africa and Western Australia. These are microfossils. Larger objects called ‘stromalites’ exist which are many centimetres across and nearly as old (three billion years). These are the results of layering of shiny mats of bacteria and clay silts (stromalites are still being formed today). Life on Earth, even as we know it, was well on its way.  hide this.

The broad trend has been from the simple and small to the complex and large. This huge variety of life and our reliance for our understanding of it on a relatively small group of professionals (and amateurs) including those tracking down and analyzing hidden fossil remains inremnants of their hidden graveyards, means that many key questions of linkage remain less that fully resolved. But gradual change, driven by ‘natural selection’ or ‘survival of the fittest’, appears undeniable – there are many fascinating examples.

A key factor in the overall evolutionary argument is that the genetic coding system used by all the actual DNA sequences of living things (animal, plant, bacteria or whatever) is identical – from the earliest bacteria through the more complex single cells with nuclei (Eukaryotes) to the slime moulds, fungi, plants and animals. The great thing too about DNA is that it is a digital sequence of codes that can therefore be reproduced very accurately most of the time (just as well) but occasionally with significant errors (just as well too) that create a variation which the environment can then test for fitness.

There appears to have been an early important role for the merging of organisms in the evolution process. Many elements of more complex cells resemble previously individual simpler organisms (bacteria). More complex life forms can therefore be seen as communities of eukaryotic cells each containing communities of domesticated bacteria. The earliest evidence of multicellular organisms is about 2 billion years ago. However, there is a large gap (1,400 million years!) between then and the significant variety of multicellular animals of the late Precambrian (‘Ediacaran’) age, 600 million years ago. This is possibly explained by the need for oxygen to have built up in the atmosphere to a sufficient level for larger animals to exist.

The great thing about the evolution of living things is that, while there is occasional trial and error (DNA error and trial really) leading to small changes beneficial to a particular DNA’s survival, because the time available for such changes is so vast (the term ‘deep-time’ has been used), significant evolutionary development is possible.

An interesting study by two Swedish scientists, Dan Nilsson and Susanne Pelger, is of how long it might take a lensed eye to develop from a flat eye. Even pessimistic assumptions about variation and heritability suggest fewer than 400,000 generations are needed for this development. There is therefore enough time in each line of animal concerned for this to have happened 1,500 times in succession. It therefore isn’t surprising that it has happened independently at least 40 times in the evolution of the Earth’s animals.

Other fascinating developments have been comprehensible by applying this understanding of gradual change over huge time periods with improvements surviving (for example the dance language of bees).

Not that all branches of the tree of life appear to experience the pressure to continue to evolve particularly significantly. One example is the fish, Coelocanth, found to be alive and well in the Indian Ocean but thought originally to have become extinct some 70 million years ago when dinosaurs were still around. Finding a live Coelocanth was the marine equivalent of finding something like a live Velociraptor. Sharks are another example of a branch of the tree of life not needing to evolve greatly to survive. Sharks similar to those around today were terrorising the seas 170 million years ago.

What then of some of the great evolutionary steps, for example from sea to land, from land into the air and from land back to water again?

The steps in the move from sea to land are far from clear. However, it seems that tetrapods (‘four-footed’ land animals and their descendants) developed limbs with digits (fingers and toes) while still very much sea-living. Coelocanths and lungfish, once thought to be the closest of fishes to tetrapods, have been overtaken in this ‘missing-link’ race by the likes of Eusthenopteron (long fish with boned, fleshy fins and heads like early tetrapods) and Elpistostegids (flat fish-like creatures with paired arm and leg positioned fins along with tails).

The steps from land into the air are perhaps clearer. Archaeopteryx, the earliest feathered fossil, has been seen very much as a ‘missing-link’ creature every since it was found. However, Archaeopteryx has many similarities to small members of a group of dinosaurs called Theropods, especially Compsognathus and Dromaeosaurs. These include hollow bones, three toed limbs and wishbones. Earlier Sinosauropteryx appears to show the early stages of feather development while Protarchaeopteryx and Caudipteryx (to mention a further two), show further stages of development. Another (fossil) bird relation, Oviraptor, has been found sitting very bird-like on its eggs, its feathers perhaps evolved for insulation rather than flight? Seemingly closer to modern birds than Archaeopteryx (i.e. having beaks rather than a reptilian snout) are Confuciusonis. Archaeopteryx is therefore just one species in a swathe of land to air evolution evidenced in the fossil record.

There is an interesting record, too, of the move by mammals from land back to the sea. Small land mammals had developed in Jurassic dinosaur times and have clearly done very well subsequently. But a move back to the sea was nevertheless an opportunity not to be missed. What appear to be the key land-to-sea ‘missing-link’ fossils, found in Pakistan, are of fox-sized beasts that looked like a cross between a wolf and a tapir. These fossils indicate whale-like skulls and teeth but ortiodactyl (goat, camel or cow-like) bodies of perhaps an estuary living creature. A still early, but more whale-like, creature, Ambulocetus, had legs that it could use only like a sea lion. The later, Basilosaurus, clearly a primitive whole, had redundant but still present hind limbs along with arms and fingers. Thus it was, apparently, that the whales of today evolved.

Of course, all these evolutionary steps were happening alongside a myriad of others across the range of living creatures, plants and animals, and in an environment that was in relation to evolutionary time scales, changing dramatically. Catastrophes of one form or another were not rare. An early massive extinction occurred towards the end of the Ordovician period, about 440 million years ago. A major extinction of Precambrian animals marks the Precambrian/Cambrian boundary about 540 million years ago. This was followed by a boom of new species.

Later massive extinctions appear to have happened at the end of the Permian period (about 250 million years ago) and at the end of the Triassic period (about 240 million years ago). These were possibly the result of climate change. But the period following saw the appearance of the majority of today’s animals.

Finally, a concentration of iridium (a meteorite element) in rock laid down at the Cretacious/Tertiary boundary (about 65 million years ago) fits well, chronologically and geologically, with the remnants of a vast meteorite crater at Chicxulub in Mexico. The end of the dinosaurs might therefore have been dramatic although a slower extinction from other events, e.g. a major bout of volcanism, is equally possible. Whatever it was, there was, again, an explosion of life to fill the vacuum left by this mass extinction leading to, amongst many other things, the emergence of the hominids.  hide this.

We are therefore all cousins of each other – albeit to varying degrees removed. By similar deduction, at least one Homo sapiens woman in history must be the ancestor (the great, many times, grandmother), of everyone. And studies of female lineage (first by Rebecca Cann) through analysis of mitochondrial DNA variation (the DNA of the domesticated bacteria (mitochondria) in our complex cells) suggest that she lived in Africa. For it became evident in the study that all the peoples of the rest of the world outside Africa are more closely related to each other and just some Africans than to many other Africans. The greatest mitochondrial DNA differences were found amongst Africans showing that our species had been in Africa longer than anywhere else. Hence, ‘Mitochondrial Eve’, as she has been called, was likely to have been an ‘African Eve’. And she didn’t live that long ago in the timescale of the New Genesis – probably only around 150,000 years ago. A subsequent similar study of male lineage (by Peter Oefnur, Peter Underhill and colleagues), in this case by analysis of Y-chromosome variation, has identified a Homo sapiens great, many times, grandfather of us all who again probably lived in Africa but in this case perhaps only 60,000 years ago – a blink of an eye in evolutionary terms. The frightening fragility of this early evolution of humans lies in the possibility indicated by some research that the sole population of Homo erectus in Africa may at one time have shrunk to as small a number as 1000. How then has humankind, in a biological sense, evolved securely from this fragile beginning.

The earliest fossil ‘hominid’ is about 6 to 7 million years hold (Sahelanthropus tchadensis) found in the Djurab desert in Chad. Evidence of the lineage around this time is minimal although it is worth noting that the differences between chimpanzee DNA and human DNA are less than those, for instance, between some species of clams or between some species of fruitfly. However, this early hominid seems very close to being a common ancestor of humans and chimpanzees – surely as near as one can get to the early hominid ‘missing-link’.

Whatever the pre-hominid/early hominid lineage, it is not inconceivable that this hominid presence was linked with changes from dense forest to more open vegetation that happened around that time. Upright walking bringing advantages in vision and head use, was evident from the skeletal form of early hominids of around 5 million years ago and footprints of an upright hominid have been dated at 3.6 million years ago.

It is worthy of note here that these early ‘human’ fossils have all been found in Africa, fitting well with the DNA indication. The earliest human fossils outside Africa are dated at approaching 2 million years ago, and are of Homo erectus, originating in Africa. The name changes from Sahelanthropus, Ardipithecus and Australopithecus to Home ergaster and Homo erectus reflect a transformation from a more ape-like to a more modern human-like form.

But this is not of course a simple lineage. The plant material eating Ardipithecus (nick-named '‘Nutcracker Man’), for instance, lived alongside other species. The extinction of many species of humankind (branches of the tree of life) is fact but the reasons unclear. Homo sapiens appeared perhaps as long as several hundred thousand years ago, again in Africa and then, as was the case for Homo erectus, appeared subsequently outside Africa – in this case about 50,000 years ago.

Another interesting, but not necessarily peaceful, co-existence of human species is that of the Neanderthals and Homo sapiens – the former being a branch off the tree of humankind closest to Homo sapiens, but still some 500,000 years ago. Java man (Homo erectus in Java) may have lived on to about 50,000 years ago when modern Homo sapiens was becoming well established elsewhere.

The replacement of earlier human species by again African originated Homo sapiens is a key element of this dominant view of human evolution, which has won out against the argument that Homo sapiens in its variant forms across the world is not a late line out of Africa but the result of independent, multi-regional evolution from earlier, hominid distributions.

Mitochondrial DNA and Y-chromosome analysis of populations across the world have identified and chronologically placed gradual migrations (rapid in the evolutionary time frame) that took Homo sapiens from Africa to all parts of the Earth over a period of 50,000 years.

A first outward coastal sweep around 50,000 years ago seems to have taken modern humankind from north-east Africa around the Indian Ocean to Australia, leaving little evidence (possibly submerged?) on the way but bringing the first hominid presence to that continent. A later (40,000 years ago) northern move into the middle east, then eastwards into Asia, split initially two ways, to inhabit central and south-east Asia about 35,000 years ago.

Central Asia was the springboard for the Homo sapiens (‘Cro-Magnon’) occupation of Europe about 30,000 years ago whilst a third strand of the eastward move from the middle-east saw modern humans occupying the Indian sub-continent.

Central Asia was, about 20,000 years ago, a springboard a second time for the occupation of north-east Asia (including Arctic areas) a prelude to a sweep across the Bering Straits and down the Americas.

The same time as this American occupation (10,000 years ago) saw the hominid re-occupation of China (Homo erectus having disappeared there some 100,000 years previously), a move from the middle-east into south east Europe and a move from the Steppes down to northern India. This global colonisation can be associated with and to some extent summarised as a sequence of hikes in population growth indicated by mitochondrial DNA mismatches (more differences equal longer growth). These indicate a 60,000 year old hike for Africans, a 50,000 year old hike for Asians and a 30,000 year old hike for Europeans.  hide this.

This was originally but incompletely as Homo erectus, perhaps a million years ago with Homo sapiens emerging from Africa about 50,000 years ago at the beginning of what has been termed (by Jared Diamond) as the Great Leap Forward. One thing is for sure, these hominid emergences coincided with dramatic ‘evolutionary’ changes from the outset.

The arrival of the Cro-Magnons, an advanced (i.e. later) Homo sapiens line in Europe about 30,000 years ago, coincided with the disappearance of the Neanderthals, a hominid branch which last showed a common ancestor with Homo sapiens some 500,000 years previously. Similarly, around 40,000 years ago, coinciding with the arrival of humans, the large animals of Australia and New Guinea disappeared. The extinction of Eurasia’s woolly mammoths and rhinoceroses and of North America’s elephants, big cats and most other large mammals also broadly coincide with human arrival. Research suggests that direct killing, man-created fires or germs are all credible explanations although other coincident factors, e.g. global warming, may have been involved or may have been the major factors. Whichever way it happened, the change in fauna associated with human arrival can be seen to have been of a truly catastrophic scale.

With humans having occupied most of the globe by about 10,000 years ago it is appropriate to turn attention to the relatively rapid evolution of human societies rather than species. The occupation by these hunter-gatherer humans of much of the globe and the killing off of much of the easier to kill fauna can be seen as a major driver towards domestication and a more settled lifestyle.

But given that most of the world’s vegetation is inedible how could this happen? Well, it can happen where the conditions are right and one such location of ideal conditions appears to have been the Fertile Crescent on the eastern edge of the Mediterranean. The climate of the area was already producing a unique concentration of vegetation similar to the most nutritious food crops (large seeded grains) of today. At the same time, the area also already accommodated a unique concentration (4 out of 5) of the most domesticable large mammals (most other species of large mammals appear intrinsically wild). The relatively large size of this Mediterranean area also contributed to the promise of both these components of this truly ‘Promised Land’.

The Fertile Crescent has been found to be a first in a number of important respects, in particular in respect of domesticated crops. It appears that the earliest domestication of chickpeas occurred in Turkey (8000 BC) and the earliest emmer wheat in the Fertile Crescent again (8500 BC). This south-western part of Asia also has the earliest evidence of animal domestication (around 8000 BC) and the Fertile Crescent in particular appears to have been the major cradle of a broad domestication of animals at around the same time (10,000 to 8,000 BC).

As with the evolution of species, the evolution from a hunter-gatherer dominated lifestyle to settled lifestyle and the evolution of domesticated crops and animals were a series of small steps over long periods of time – about 10,000 years. Helping these changes were an increased availability of domesticable crops (perhaps associated with climate change), technological developments (sickles, baskets, pestles and mortars and so on), population densities (in a circular relationship with food production) and the displacement of hunter-gatherer societies.

Man spread the effects of this food production bombshell, by learning or displacement, rapidly across western Eurasia and subsequently over the rest of the world, although a degree of independent domestication is evident. The east-west orientation of Asia’s major axis is considered a key factor in this with crops able to cope with similar climatic and seasonal conditions.

Almost needless to say, the spread around the world of food production, often involving transported species, was associated with the evolution of societies from band to tribe to chiefdom to state.

There were a number of coinciding advantages of a more settled lifestyle associated with plant and animal domestication. In particular, a high birth rate could be maintained and food surpluses could be stored. This in turn enabled societal specialisms and structure to arise – administrators, soldiers and priests, the essentials of successful conquest. So it is that societal evolution has been from the small and simple to the large and complex just as in the evolution of life, and can be seen also as a ‘natural selection’ or ‘survival of the fittest’ evolutionary process.

The labour requirements of food production are intermittent and freed labour for basic societal activity. Food surpluses could provide for non food-production roles including religious and political elites and of course soldiers. These together provided for the development of the physical construction of society – buildings and technology. In turn, smaller, simpler societies neighbouring much larger, more complex societies had, on the whole, to adopt the same approach or be subsumed or destroyed by them. So, broadly speaking, is the pattern of the last few thousand years.

Food production and domestication of animals had other direct and indirect roles in this conquest-based evolution of societies. Crops and livestock provided clothing and storage materials and domesticated animals were major sources of power and transport. Eurasia’s horses, in particular, have been the key to many of the world’s greatest conquests for thousands of years. Indirectly, but equally important is the role of germs associated with the domestication of a wide variety of animals. A range of historically deadly human germs appear to be mutants of animal versions. Thus epidemics amongst invaded societies have been decisive in many of the ‘great’ conquests of peoples.

Finally, the longer history of Eurasia’s settled societies, arising in essence from the early crop and animal domestication potential of their homeland, enabled the earlier development of a range of technologies. The harnessing of energy sources, the application of the wheel, the production of metals (copper, bronze, then iron) and the development of sea transport were some of the keys to yet more complex societal development and further conquests facilitated by knowledge transfer associated with the development of language, spoken and written.

It is perhaps appropriate to note in the context of the more developed human societies that it is not just micro-organisms that man has transported with such devastating consequences. Alien species, animals or plants, transported by man, are amongst the major threats to biodiversity and, perversely, are seemingly more so in the most bio-diverse areas. Man is extinguishing tens of thousands of species each year.

Thus is the Earth like it is, dominated, it seems, by humans and their favourite or otherwise concomitant crops and animals. There is though a salutary lesson, perhaps, in the current state of the once ‘Fertile Crescent’ – denuded, eroded and left behind, unbefitting its historical and indeed historic role.  hide this.

Thus it is appropriate and timely, in this epilogue, to look at some wider societal, then global, then solar, then galactic and finally universal prospects which life in its current form, or some other, is likely to face.

There are about 6 billion human beings now alive and over the next 100 years, more than twice that number will have started their lives. What we are doing now will therefore undoubtedly impact on twice as many people as are here. Scientists have noted that we are the first generation to influence global climate and the last to avoid its consequences as we change Earth more rapidly than we are understanding it.

This process of change has been seen as not unconnected with Moore’s Law. Gordon E Moore, the co-founder of chip maker Intel, predicted back in 1965 (based on a strong, then recent, trend) a doubling each year of the number of components on a microchip. This one law became a variety of ‘Moore’s laws’ predicting exponential growth across a range of aspects of human consumption. Such exponential growth has been seen to point to a singularity, a breakdown of the way things work as we know it, just into the century we have already begun. The dismemberment implied by this black hole like version is perhaps immediately seen as a societal phenomenon. However, it is one with global implications.

Global warming is now an accepted phenomenon to the overwhelming majority of appropriately knowledgeable scientists. A narrow interpretation of the impact of a predicted 1.5 to 6oC increase in average temperature over the next century appears comfortable. But the possible catastrophic consequences evident from studies of deep history cannot be discounted. Evidence of a period of catastrophic global warming about 55 million years ago suggests the feasibility of a ratchet like process in which a relatively slow but steady initial rise triggers a first step-change effect, perhaps the burning, or otherwise dying of significant areas of the Earth’s forests as a threshold temperature is reached. The further global warming initiated then triggers a second step-change effect, perhaps the bubbling up into the atmosphere of the (global warming) methane stored in the poles’ permafrost and below the Earth’s oceans. The impact of such stepped, probably irreversible global warming processes, whilst not disastrous to all life on Earth would be catastrophic to human existence – not dissimilar to the impact of a comet or asteroid. In respect of the latter, recent astronomic thinking suggests large asteroids of catastrophic impact proportions will strike the earth every 100,000 years or so with mass extinction outcomes of the kind that could have destroyed the dinosaurs and much other life. Both types of catastrophic event can be expected to stretch beyond the limit, the hitherto seemingly remarkable ability of the Earth to regulate itself – an ability seen by some to justify consideration of the Earth as a single living organism, Gaia.

Turning to the scale of the solar system, an essentially unarguable prospect is that some 4½ million years from now, our Sun, the giver of life to our planet (and born a similar number of years ago), will run out of energy. As this happens, it will expand massively into a Red Giant, filling half of the Earth’s sky, and scorch all life on Earth out of existence. Finally, it will shrink back to become a white dwarf, gradually fading away to become a black dwarf.

A rather longer life belongs to our galaxy, the Milky Way. Astronomers can observe galaxies in various stages of collision. The expectation is that our Milky Way will eventually merge with M31, another spiral galaxy in the Andromeda constellation. A relatively small elliptical galaxy would form. Further mergers of elliptical and other galaxies appear to form yet larger elliptical galaxies. Thus an evolution of galaxies is now a recognised cosmic phenomenon.

The ultimate evolution, in a four dimensional view of things, has been hypothesised by John Gribbin. He identifies black holes as the seeds of new universes, with our Universe having grown from such a seed in another universe. Our Universe’s laws of physics, which encourage the formation of black holes, are thus seen to be as they are because ‘natural selection’ processes have favoured universes which are prolific progenitors of black hole seeded offspring.

Beyond the four dimensional perspective, branes have been envisaged which oscillate to and fro along a fifth dimension and collide regularly to create four (and more) dimensional universes which would overwhelm our own.

Several prospects, therefore, present themselves to our Universe including: its collapse back into, and perhaps rebirth from, a black hole almost singularity (all dependent on whether or not there is enough matter in the universe to reverse its expansion and that gravity pulls more than it pushes); some unfathomable jostling for room in space-time (and maybe further dimensions) with a new, genetically close, universe bursting out of one of our own multiplicity of black hole seeds; or engulfment by a new universe triggered by colliding branes.

It is appropriate, therefore, to conclude with a reiteration of the introductory note, perhaps now more clearly justified, that the awe-inspiring nature of our Genesis (and prospects) should remind us constantly of how insignificant we all are in the universal scale of things, how vulnerable we are, how bound up we are with what surrounds us, and why we should cherish the resources we have literally at our disposal – and maybe act accordingly now. In the mid-term (on the human survival scale of things) a temporary extension of our existence might require an Exodus or two, a fitting sequel to our Genesis.  hide this.