AFTER about 60 years of searching, the most renowned result of the search for extra-terrestrial intelligence (SETI) was the Wow! transmission, a strong narrowband radio signal received on August 15, 1977, by Ohio State University’s Big Ear radio telescope in the United States. The signal appeared to come from the direction of the constellation Sagittarius but was not modulated – that is, it was not carrying information – and it did not recur.
In the year 2000 SETI@home was launched, a distributed computing project in which volunteers donated idle computer power to analyse radio signals for signs of such intelligence. After 20 years no anomalous signals had been found and the project was stopped.
In 2016 Stephen Hawking and a Russian billionaire, Yuri Milner, commenced a $100million effort called ‘Breakthrough Listen’, employing the services of the world’s largest radio telescopes for thousands of hours. The project is continuing, but as of now, after scanning 60million star systems in our galaxy, no inexplicable transmissions have been detected (an apparent signal turned out to be from local sources).
The electromagnetic spectrum, with its far-reaching radio-frequency waves, is the only way we know of that a universe organised and operating under Einstein’s concepts could communicate across galactic distances – and then not very well. There may be other concepts, but they are unrecognisable to us; the only insight we possess is Haldane’s comment that ‘not only is the universe queerer than we know, it is queerer than we can know’.
Why this radio silence? Perhaps because we are the first. The roughly 14billion years of the universe’s existence may be too short a period for a recurrence of the unlikely combination of circumstances that gave rise to us. As far as we can tell, in practical terms humankind is the only sensate and intelligent being in our universe. We are utterly alone, riding around on our 4.5billion-year-old spaceship, tethered to the nearest star.
Why us? Why here? Why now?
Three reasons. If there is to be existence of a sort we can relate to, then number one is the need for the presence of liquid water: not steam, not ice. This is the foundation for the complex organic chemistry that makes life – that is, species reproduction – possible. It is a constraint that reduces the chances of any given planet having the right chemistry in the right conditions to almost zero.
The second reason is that all biology is evolution; species that do not or cannot evolve in Earth’s changing environment are transient. Once reproduction starts, perhaps initially a simple shedding of copies, a rapid generation and screening out of mutations is required for evolution to come up with better adapted survivors. The extreme variability of earth’s environment does this, providing a rigorous, ruthless and unending testing ground for any genetic innovations that arise.
For, truth to tell, our planet, the pretty blue one with its swirls of white cloud, is a very challenging place when looked at in geological time. Its surface consists of plates floating on a globe of molten metal, crashing and buckling. The ensuing earthquakes and volcanoes change landforms and climates. Then we have the perturbations in the earth’s orbit arising from the gravitational interactions of the sun and moon. These complicate the seasonal weather patterns, which themselves constantly present annual challenges and opportunities. Asteroid impacts can cause disastrous climatic phenomena, wiping out whole classes of species. Finally we are doused with radiation that can cause mutations, almost none of which are beneficial. So the smiling face of the blue planet is misleading.
The third reason we exist is our moon. Unusually we have a single, very large one that is capable of regularly dragging the surface of the seas up their shorelines to form an immense intertidal area in which amphibians can thrive. By creating these tidal flats it hastened the evolution of life from aquatic to terrestrial, so unlocking access to a great number of ecologies at a relatively early stage in the history of our planet. The resultant diversity gave rise to us.
So our home is a rough place and we are its rough products, rugged and aggressive survivors of the constant challenges it presents. The successful product of evolution in this environment is the warrior, capable of seeing off intruders while foraging for subsistence.
But warriors we may have been, worriers are what we have become. The vistas of knowledge opening before humankind lead ever deeper into uncertainty as to what may become of us. One key evolutionary trick has made us rapidly become the dominant species on earth, perhaps in the universe. This is something that was discovered only about 40 years ago: epigenetics.
To go back a bit, until Charles Darwin (1809–1882) came up with a convincing evolutionary theory of natural selection, it was generally assumed that physical characteristics – height, for example – could be acquired from lifestyle choices and bequeathed to one’s offspring. This was the proposal of Jean-Baptiste Lamarck (1744–1829) and Lamarckism was the theory of the creation of species as a direct response to their current environment.
This was overturned by Darwin whose insight was that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete and reproduce. The survival of the fittest. Done and dusted.
Actually, no. In the 1970s science made two revolutionary discoveries. First it was found that a set of alien genes – mitochondria – work as sub-contractors in every human cell, organising its energy supply. Then came the recognition that there are inheritable changes that do not involve alterations to the underlying genes but still affect how cells interpret them. The new discipline of epigenetics made Darwinism seem rather passé. Indeed, now we are coming to understand that genes are essentially independent life forms, and that they too are survivors of countless forays beyond the limits of the cell. It turns out that Lamarckism had a kernel of truth.
Epigenetics – evolution at warp speed – is still at its exploratory stage as a discipline but results are coming thick and fast, as are the worries. In 2015, a group of leading biologists proposed a worldwide ban on the use of certain new and very quick methods that allow the editing of the human genome in such a way that its outcomes can be inherited. They had reason; in April of that year Chinese researchers reported the results of editing the DNA of non-viable human embryos. In 2019 a Chinese court found that three scientists had misled doctors into unknowingly implanting gene-edited embryos into two women. This year scientists have created embryos that are a mix of human and monkey cells, part of a project to find new ways to produce transplant organs.
Humankind, with its unique ability to envisage distant outcomes, has always been a worrier. Now this invaluable trait is being stretched by the worrying Pandora’s Box that modern genetics has sprung wide open. Perhaps we should have stuck to Darwinism, a concept that warriors, at least, would feel at home in.
Perhaps, too, SETI’s failure to detect other civilisations is for the best. Elon Musk, SpaceX’s founder and CEO, wants humanity to become a ‘spacefaring civilisation’ and a ‘multi-planet species’. He has the resources to get us to Mars, and, using technologies as yet unknown, we may start exploring the galaxy. Best that our aggressive species does not encounter aliens. A real ‘Star Wars’ will be ghastly and probably fatal to one side or the other. We already have enough to worry about.