Viruses may exist ‘elsewhere in the universe’,
warns scientist
Prof Paul Davies suggests viruses may form vital part
of ecosystems on other planets
A range of microbes and other microscopic agents may
be needed to support life on other planets, including viruses.
Nicola
Davis Science correspondent
@NicolaKSDavis
Mon 6 Sep
2021 11.55 BST
The Covid
pandemic has already turned life as we know it upside down – and no doubt
prompted some people to want to leave the planet.
Now a
leading scientist has warned that viruses may not only be found on Earth, but
might occur – should life exist – elsewhere in the universe.
Prof Paul
Davies, an astrobiologist, cosmologist and director of the Beyond Center for
Fundamental Concepts in Science at Arizona State University, said that the idea
of aliens ranges from microbial life to super advanced civilisations that might
be signalling to us.
But Davies
backed the idea that a wide range of microbes and other microscopic agents
would probably be needed to support life as a whole, whatever form it takes.
And it seems viruses – or something that performs a similar role – could be
part of the equation.
“Viruses
actually form part of the web of life,” said Davies. “I would expect that if
you’ve got microbial life on another planet, you’re bound to have – if it’s
going to be sustainable and sustained – the full complexity and robustness that
will go with being able to exchange genetic information.”
Viruses,
said Davies, can be thought of as mobile, genetic elements. Indeed, a number of
studies have suggested genetic material from viruses has been incorporated into
the genomes of humans and other animals by a process known as horizontal gene
transfer.
“A friend
of mine thinks most, but certainly a significant fraction, of the human genome
is actually of viral origin,” said Davies, whose new book, What’s Eating the
Universe?, was published last week.
According
to Davies, while the importance of microbes to life is well known, the role of
viruses is less widely appreciated. But he said if there is cellular life on
other worlds, viruses or something similar, would probably exist to transfer
genetic information between them.
What’s
more, he said, it is unlikely alien life would be homogenous.
“I don’t
think it’s a matter that you go to some other planet, and there will just be
you one type of microbe and it’s perfectly happy. I think it’s got to be a
whole ecosystem,” he added.
While the
thought of extraterrestrial viruses may seem alarming, Davies suggests there is
no need for humans to panic.
“The dangerous
viruses are those that are very closely adapted to their hosts,” he said. “If
there is a truly alien virus, then chances are it wouldn’t be remotely
dangerous.”
Davies’
comments come after a study, published in late August, suggested that signs of
life may be detected beyond our solar system within two to three years.
But the
need to consider entire ecosystems does not only apply when considering alien
life.
Davies –
whose conversation is peppered with nods to former colleagues and associates
from Stephen Hawking to Fred Hoyle, the great if unconventional former director
of the Institute of Astronomy at Cambridge University – said it is also
important should humans attempt to colonise another planet.
“Most
people think about, well, we would need to have very large spacecraft, and then
sort of recycle things for the very long journey, and then all the technology
you’d need to take,” he said.
“Actually,
the toughest part of this problem is what would be the microbiology that you’d
have to take – it’s no good just taking a few pigs and potatoes and things like
that and hoping when you get to the other end it’ll all be wonderful and self
sustainable.”
While Covid
has left most of us with a dim view of viruses, Davies said they are not all
bad. “In fact, mostly, they’re good,” he said.
Among their
positive roles, viruses that infect bacteria – known as phages – can help keep
bacterial populations in check, while viruses have also been linked to a host
of other important processes, from helping plants survive in extremely hot
soils to influencing biogeochemical cycles. And, as Davies notes, a significant
fraction of the human genome may be remnants of ancient viruses.
“We hear
about the microbiome inside us, and there’s a planetary microbiome,” said Davies.
But, he argues there is also a human and planetaryvirome, with viruses playing
a fundamental role in nature.
“I think
without viruses, there may be no sustained life on planet Earth,” he said.
.jpeg)
.jpeg)
.jpeg)
.jpeg)
Sem comentários:
Enviar um comentário