• Question: I Know there has to be other life forms in the galaxy, but is it not impossible for there to be other humans just like us?

    Asked by yourmum to Meeks, Pete, Stephen, Steve, Tom on 21 Jun 2010 in Categories: .
    • Photo: Marieke Navin

      Marieke Navin answered on 18 Jun 2010:

      Hello again yourmum I don’t see a reason why not…a rocky planet, similar temp, similar distance away from a similar star…it’s totally feasible i think…space is so so so vast with so many stars and planets and there isn;t anything particularly special about us

    • Photo: Tom Hartley

      Tom Hartley answered on 18 Jun 2010:

      Almost impossible. But parallel evolution is a remarkable thing. Very different creatures that live similar lives in similar environments end up looking and/or behaving similarly because the same features are adaptive – helping them survive and reproduce. E.g., Dolphins are more closely related to dogs than to sharks (I would imagine – I haven’t checked in detail), but they look (and behave?) much more like a shark than a dog, don’t they? At night you might easily mistake a bat for a little insect eating bird (such as a swift) they have similar lifestyles and have evolved similar structures and behaviours. So maybe aliens (living in big groups on an earthlike planet) might be more like us than some of our close relatives.

      I actually think aliens would be very different (most of them anyway), because they would probably have VERY different chemistry, “genetics” and “metabolisms” that might not look anything like life on Earth.

    • Photo: Stephen Curry

      Stephen Curry answered on 19 Jun 2010:

      Really good question – I agree that it is very likely that there are other life forms out that but suspect it is not likely that they will be ‘just like us’.

      My reading of the history of the world tells me that the evolution of life is a process that is full of accidents and unexpected twists and turns. There are so many different factors that have affected evolution over the past several billions of years – volcanoes, meteorites, solar activity, the changing shape of the earth’s land masses.

      In fact I suspect that if you started again with an identical earth in exactly the same solar orbit, that after 4 billion years you would not see humans emerging. You might get many animal forms that are similar to what we have now but there is no plan or inevitability of human existence from the humble beginnings of self-replicating molecules emerging from a lightning-powered soup of chemicals.

      Just be glad that it has happened, and that you are here to ask this question!

    • Photo: Pete Edwards

      Pete Edwards answered on 21 Jun 2010:

      Like you I think there will be other forms of intelligent life in the universe somewhere. However, I doubt very much that they will be exactly like humans – the evolution of life on earth has adapted to lots of random events and it is very very unlikely that exactly the same set of conditions would occur anywhere else.

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