When it comes to extra-terrestrials, you'd be forgiven for picturing them as little green men.
But Britain's top biologist has claimed they could be much bigger, and far more terrifying than the man on your packet of Space Raiders. According to Richard Dawkins, life in other solar systems - if it exists - could be spider-like creatures as big as elephants.
Life on another planet with a similar make-up to Earth would probably be not too different from human beings, according to the renowned academic who has honorary doctorates from 12 different universities. Dr Dawkins specialises in evolutionary biology, and has authored several books on his studies.
But according to him, any life on planets different to ours would be much less welcoming. A weaker gravitational pull, Mr Dawkins claims, would impact evolution, resulting in "animals the size of an elephant built along the lines of spider", Daily Star reports.
Anyone setting foot on a planet with stronger gravity however could expect to find aliens the size of a "mouse" which would be "built along the lines of a rhinoceros". Emeritus fellow Dawkins, 82, is widely regarded as one of the world's leading science experts and has appeared in countless documentaries, was the voice of Q42/Computer in 2020 movie Intercept, starred as himself in Doctor Who and The Simpsons and featured on an album by Finnish heavy metal band Nightwish.
Trophy hunters just 'like ISIS terrorists' says former African presidentAsked for his views on aliens on a YouTube question and answer session, Dawkins said: "I'm pretty sure there will be extraterrestrial life.'' But he said he thought it would exist so far away it was unlikely aliens had landed on Earth and first contact would probably be by radio.
"It might look like us,'' he said. "If you look at the history of life on our planet it is uncanny how convergent evolution works, how very often the same solutions come up to the same problems.
"Australian fauna, for example, is extremely like the rest of the world's. The parallels between Australian animals and the rest of the world's are very striking.
"It would not be unlikely if there is another planet like ours, maybe even creatures rather like us might evolve. And also carnivores and herbivores. If the gravitational field is very different then no, that's quite different.
"Say it's a much weaker gravitational field then you'd expect that animals the size of an elephant would be built along the lines of spiders. Or if it's a very strong gravitational field animals the size of a mouse would be built along the lines of a rhinoceros.
"But if it was the same distance from its star as ours is and if the chemical balance was roughly the same, I think it's not unlikely that we would get a whole range of animals similar to ours.''