Hollywood films and science
fiction literature fuel the belief that aliens are other-worldly, monster-like
beings, who are very different to humans. But new research suggests that we
could have more in common with our extra-terrestrial neighbours, than initially
thought. The new research predicts that alien on other planets may evolve
almost exactly like us.
In a new study published in
the International Journal of Astrobiology scientists from the
University of Oxford show for the first time how evolutionary theory can be used to support
alien predictions and better understand their behaviour. They show that aliens
are potentially shaped by the same processes and mechanisms that shaped humans,
such as natural selection.
The theory supports the
argument that foreign life forms
undergo natural selection, and are like us, evolving to be fitter and stronger
over time. Sam Levin, a researcher in
Oxford's Department of Zoology, said: "A fundamental task for
astrobiologists (those who study life in the cosmos) is thinking about what
extra-terrestrial life might be like. But making predictions about aliens is
hard. We only have one example of life - life on Earth—to extrapolate from.
Past approaches in the field of astrobiology have been largely mechanistic,
taking what we see on Earth, and what we know about chemistry, geology, and
physics to make predictions about aliens.
"In our paper, we offer
an alternative approach, which is to use evolutionary theory to make
predictions that are independent of Earth's details. This is a useful approach,
because theoretical
predictions will apply to aliens that are silicon based, do not have
DNA, and breathe nitrogen, for example."
Using this idea of alien
natural selection as a framework, the team addressed extra-terrestrial
evolution, and how complexity will arise in space.
Species complexity has
increased on the Earth as a result of a handful of events, known as major
transitions. These transitions occur when a group of separate organisms evolve
into a higher-level organism - when cells become multi-cellular organisms, for example. Both theory
and empirical data suggest that extreme conditions are required for major
transitions to occur.
The paper also makes
specific predictions about the biological make-up of complex aliens, and offers
a degree of insight as to what they might look like. Sam Levin added: "We
still can't say whether aliens will walk on two legs or have big green eyes.
But we believe evolutionary
theory offers a unique additional tool for trying to understand what
aliens will be like, and we have shown some examples of the kinds of strong
predictions we can make with it.
"By predicting that
aliens undergone major transitions - which is how complexity has arisen in
species on earth, we can say
that there is a level of predictability to evolution that would cause them to
look like us.
"Like humans, we
predict that they are made-up of a hierarchy of entities, which all cooperate
to produce an alien. At each
level of the organism there will be mechanisms in place to eliminate conflict,
maintain cooperation, and keep the organism functioning. We can even offer some
examples of what these mechanisms will be.
"There are potentially
hundreds of thousands of habitable planets in our galaxy alone. We can't say
whether or not we're alone on Earth, but we have taken a small step forward in
answering, if we're not alone, what our neighbours are like."
Via Phys.org