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8 Aliens May Be More Like Us

These illustrations represent different levels of adaptive complexity we might imagine when thinking about aliens. (a) A
simple replicating molecule, with no apparent design. This may or may not undergo natural selection. (b) An incredibly
simple, cell-like entity. Even something this simple has sufficient contrivance of parts that it must undergo natural selection.
(c) An alien with many intricate parts working together is likely to have undergone major transitions. Image credit:

Helen.S.Cooper

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