The Forbidden Universe (34 page)

The idea that seeding occurs via comets has received strong support from the study of meteorites, especially fragments from the famous specimen believed to be from the nucleus of a comet that exploded over the small Australian town of Murchison, Victoria, in 1969. Analysis of the Murchison meteorite has continued ever since – the latest batch of test results, after examination with
cutting-edge
techniques, was released in February 2010. One of the first things to be discovered was that it was made up of organic carbon chemicals – it even smelt of petrol. It contains 70 different amino acids, including two, glycine and alanine, which are fundamental to life on earth – the very same, in fact, as those that emerged from the
Urey-Miller
experiments with the primordial soup that so excited scientists back in 1953.

There is an even more direct connection between comets and glycine, which is chemically the simplest amino acid. In 1999 NASA launched the probe Stardust to collect material from the comet Wild-2, which orbits the sun once every six years. In January 2004 Stardust swept up dust from the comet’s coma – the cloudy halo around the nucleus – returning it to Earth in a sealed container nearly two years later. Analysis revealed the presence of glycine. As Dr Carl Pilcher, head of NASA’s Astrobiology Institute announced:

Some of the greatest revelations have come from attempts to reproduce interstellar conditions in the laboratory, in what is effectively a cosmic version of the Urey-Miller
experiments
. At the forefront of this quest is the NASA Ames Research Center in the 1990s with a team led by Louis Allamandola.

Allamandola set out to study how dust grains in gas clouds interact with the gases by replicating the conditions. He and his team placed methane, water vapour, ammonia, carbon monoxide and so on in extremely thin densities and very, very cold temperatures and bathed them in ultraviolet radiation. Under these conditions, chemical reactions occur that would be impossible under normal earthly conditions. The radiation breaks apart the molecules, and the icy cold puts them back together in very unusual and complex ways. But although many of these structures had never been seen before, some were eerily familiar to biochemists …

The first surprises related to the PAHs. Interstellar conditions, particularly exposure to ultraviolet,
transform
the PAHs’ carbon into useful forms for life such as alkaloids – ‘ubiquitous in the plant world’
⁹
– and quinones, essential for photosynthesis and the functioning of muscle and brain cells. These vital substances simply wouldn’t exist without the gas and dust clouds in deep space. But there were even more ground breaking discoveries.

Back in 1985, American biologist David Deamer had discovered something very odd in the Murchison meteorite: small ‘bubbles’ closely resembling biological structures known as vesicles – basically membrane sacs containing liquid biochemicals that constitute part of cells. But were they really vesicles? It was only in the late 1990s that Deamer realized the potential of Allamandola’s work: Could it be that similar bubbles had appeared in his simulated interstellar environment? Indeed they had. They found identical vesicles, about the size of red blood cells. They called in biochemist Jason Dworkin – a former collaborator with Stanley Miller – who identified them as lipids, a class of macromolecule that includes fats and waxes.

Lipids perform several vital functions, but most tantalizingly they make up the membranes of cell walls, which may be small but are in fact big operators. They separate biochemicals into packets – capsules, basically. Without them many of the processes and reactions vital to the development of life could never happen because the biochemicals would be too dilute. As geneticist Pascale Ehrenfreund, specifically commenting on the Ames discovery, pointed out, ‘membrane formation is a crucial step to the first forms of life.’
¹⁰

Researchers trying to replicate the origins of life had never previously had any success in replicating lipids under terrestrial conditions. But here, in interstellar gas clouds, they appeared utterly spontaneously – in fact, the Ames team never noticed they had made lipids until David
Deamer asked them to look. The similarity with the vesicles found in the Murchison meteorite shows that this process really does happen in space. It isn’t just the Frankenstein child of jiggery pokery in a lab.

In other experiments, Allamandola’s team demonstrated that not merely cell membranes, but some of their internal biogenic chemicals – ammonia, formaldehyde and even amino acids – can also be made in the interstellar clouds. Allamanodola speculates that the first cells could have come from inside comets – all the ingredients are there, and so is the membrane to neatly wrap them up – although he admits that this theory is untestable.
¹¹
At least at the moment.

In fact, Allamanodola wasn’t the first to make such a suggestion. With so many of life’s building blocks being found in space, Fred Hoyle and Chandra Wickramasinghe had suggested back in the 1970s that they could be developed into what they termed ‘protocells’ that could then be seeded onto planets by comets. The Ames discovery shows this is almost certainly correct.

To us the important thing, though, was the implications of creating lipids in the lab. As Louis Allamandola pointed out:

The universe – not just planets, but space itself – is bursting with the potential and materials for life, created and transported around like ocean currents carrying seeds
between remote islands. However, it is still only on planets that these can develop into something more complex than bacteria at best, which brings us to another even more controversial idea that fits very neatly into the ‘universe designed for life’ vision.

The Gaia hypothesis was proposed in the 1970s by British scientist James Lovelock, who is even more of a maverick or independent thinker, depending on your point of view, than Sir Fred. Similarly, Lovelock’s brilliance is acknowledged even by his critics (even if they believe his imagination sometimes gets the better of him), as are his very real contributions to science.

Lovelock describes himself as an ‘independent scientist’, neatly encompassing both his attitude to the freedom of thought he believes is essential for a scientist and his avoidance throughout his long career of being tempted by commercial or even academic institutions – although he has occasionally been successfully headhunted as a consultant. With his broad knowledge of all the sciences, and contempt for the increasing specialization that blinkers scientific thinking, he would have been at home in the Renaissance.

Lovelock is that rare being, someone whose brilliance has actually changed the face of the world. Most significantly, this occurred in the early 1970s through his discovery that human-made chlorofluorocarbons (CFCs) had penetrated the environment to such a degree they were present in places as remote from human industry as Antarctica. It was because of Lovelock that today’s world is CFC-free.

The concept behind Gaia was a spin-off of Lovelock’s work for NASA in the 1960s, when he was devising ways to detect life on Mars. He reckoned analysis of the Martian atmosphere might reveal the characteristic changes caused by the presence of living organisms. Looking further into this question and the impact life has on the Earth’s atmosphere led him to certain striking observations. It isn’t just that the presence of plants and animals – the biosphere – changes the atmosphere, but they appear to be regulating it, actively keeping the Earth habitable. Life itself keeps the planet in a condition suitable for life.

From such phenomena Lovelock developed the idea that the Earth is a ‘self-regulating entity’, where living things are not passive guests but ensemble players with integral parts in shaping conditions on the planet.

A prime example of this self-regulation, besides a host of others, relates to the Earth’s response to changes in the sun’s output. Living organisms can only survive within a narrow range of temperatures, about 10 to 20 degrees centigrade. However, although astrophysicists agree that since life first appeared on Earth at least 3.5 billion years ago the sun’s heat has increased by about 30 per cent, the Earth has obviously remained at a temperature suitable for life. Somehow the increasing heat has been balanced to keep the average global temperature steady.

As a 2 per cent drop in the heat reaching Earth from the sun is enough to trigger an ice age, imagine what the Earth would be like with 30 per cent less heat. When life originated, something – probably a high level of greenhouse gases in the atmosphere – made the Earth significantly warmer than it would have been otherwise. But as the sun grew hotter, some other factor must have altered conditions – the mix of gases in the atmosphere, for example – as compensation. And that unknown factor had to keep step with the steady increase in solar heat.

As Lovelock pointed out, any of the processes that have been proposed to explain this compensation would have had to be staggeringly precise. Even small variations in, say, the mix of atmospheric gases would result in runaway reactions that would either seriously overheat the Earth (the oceans would literally boil away), or reduce it to a frozen
ball. Yet that clearly didn’t happen; the process seems somehow to have been controlled.

Following the suggestion of his neighbour, the novelist William Golding, Lovelock called this the ‘Gaia hypothesis’, after the ancient Greek Earth goddess. In 1979 he produced
Gaia: A New Look at Life on Earth
.

When Gaia was first published there were howls of outrage from the scientific world, led predictably by Richard Dawkins. (Lovelock declared that he ‘hated Gaia as much as he hates God’.)
¹⁴
Dawkins condemned Lovelock’s system because to him it could never have evolved by natural selection, while Lovelock maintains that it fits natural selection perfectly. However, as a 2010 BBC documentary on Lovelock’s work showed, much of the thinking behind the once-controversial Gaia hypothesis has now become mainstream, while some still regard Lovelock’s idea as oddball and over-imaginative, others, including the philosopher John Gray, consider the idea as revolutionary as Charles Darwin’s.
¹⁵

Despite widespread belief to the contrary, what the Gaia hypothesis does
not
proclaim is that the world is alive in the same way that an animal is alive, or that it is somehow self-aware, with some higher planetary consciousness controlling and ordering the individual parts to benefit the whole. In fact, Lovelock is scathing about the New Age, which took (or most probably, hugged) his book to its heart, believing in some way that it was scientific proof of the reality of the Mother Goddess. To Lovelock such concepts exist outside the realm of science, since they can’t be tested
by scientific methods.
¹⁶
Lovelock uses the term ‘alive’
metaphorically
, taking pains to explain - with superb chutzpah, but pinpoint precision – ‘the planet is alive in the same way that a gene is selfish’.
¹⁷
To him the Earth fits the definition of a ‘superorganism’: ‘bounded systems made up partly from living organisms and partly from non-living structural material’
¹⁸
– as, for example, a beehive. Literal
interpretations
of the word ‘alive’ also seems to be behind Dawkins’ hostility, which implies a certain lack of
sophistication
in his understanding or perhaps an unwillingness to confront the theory properly.

The Gaia theory is what one would expect, indeed predict, from the designer universe hypothesis. If the universe is fine-tuned to support life, and life is a cosmic imperative arising wherever conditions are conducive, then one would expect that once complex life did take hold on a planet, some kind of mechanism would be in place to ensure its survival. We should recall here the concept of the
anima mundi
, the ‘world soul’, which animates and also controls the world so dear to the Hermeticists’ hearts.

But however exciting the Gaia hypothesis might seem, we should remember it has yet to be conclusively proven. Nor does it prove the designer universe theory correct. But, as with the existence of biochemical evidence in support of the cosmic imperative, it nevertheless fits and supports the concept of a designer universe.

It no longer seems a question of whether panspermia happens – it does, quite clearly – but rather of how far the building blocks of life can be fused in space before they need a planet to really get going. Christian de Duve sums up the current state of our knowledge: