If we're all Martians now, who are the aliens?

'The evidence seems to be building
that we are all actually Martians;
that life started on Mars and came
to Earth on a rock," Prof Steven
Benner told the Goldschmidt
meeting, this week's international
scientific convention in Florence.
The theory that microbes from
Mars "infected" the Earth via
meteorites, finding conditions here
more conducive to their evolution,
is nothing new. But Benner's
theory, that the minerals essential
to life's formation were only
readily available on Mars, is. Such
a notion challenges almost every
aspect of human culture, from
biology to philosophy and faith –
and practically every science
fiction scenario in the book.
Long before HG Wells' War of the
Worlds threatened the home
counties with a Martian invasion,
we humans were looking up at the
red planet, coursed as it seemingly
was by canals constructed by
extraterrestrials, imagining the
worst. From John Wyndham's
scary triffids to Tim Burton's kitsch
Mars Attacks! , dystopian science
fiction has ever been predicated on
the fearful alien other. How ironic
to discover that we were the aliens
all along.
There are serious questions here.
For centuries philosophers have
pondered the effect that the
discovery of extraterrestrial life
might have on human religions –
could Christianity sustain itself in
the light of evidence that we are
not alone? Yet the Vatican's chief
astronomer, Gabriel Funes,
recently announced that Catholics
should actually welcome aliens as
our extraterrestrial brothers,
quoting Dante's Inferno as his
mission statement: "Where we
came forth, and once more saw the
stars."
One has to admire the sheer
optimism of modern science: I love
the fact that there is such a
discipline as astrobiology, whose
practitioners' task is to imagine
what life might be like on other
planets. Yet here on the home
planet we have profoundly strange
aliens of our own. It is in the
deepest undersea volcanic vents
that we can look back into what
life might have been like , at that
moment of contamination. How
odd that we see those bizarre
creatures of the Stygian depths,
with their eerie antennae and
sightless eyes, and regard them as
alien, when they are, after all, our
distant ancestors.
And is it not part of our human
hubris that we should presume all
aliens to be weird versions of
ourselves – somewhat ignoring the
wonderful weirdness we ourselves
represent? Hairless apes, pretty
much inept at most things,
increasingly reliant on the
machines we have devised – and
which in turn now threaten our
own destruction.
In 1896 the American astronomer
Percival Lowell hypothesised about
"Mars as the abode of life." He
presumed that an advanced
civilisation had flourished on
Mars, but was dying, despite its
desperate attempts to re-engineer
its climate by using those canals to
tap the planet's polar ice caps for
water. And for all that this
civilisation had sought to prevail
over its environment, "What [was]
found inconvenient or unnecessary
to enslave, it would exterminate, as
we have obliterated the bison and
domesticated the dog."
Lowell's vision inspired Wells'
nightmare of technologically
advanced but rapacious aliens
invading Earth to appropriate our
resources. Doubly ironic, then, that
we were the real Martians, and that
many people – including quite a
few scientists – believe that we're
accomplishing that same scenario
with equal rapacity. A century
after Lowell, James Lovelock's Gaia
theory posited that the planet would
outlive its human infestation,
shrugging it off as a temporary
blight like a plague of greenfly,
leaving barely a trace of our
insignificant sway behind. As
David Bowie, another alien who
fell to Earth, sang in Life on Mars :
"It's a Godawful small affair."