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Aliens probably long dead, say scientists

Discussion in 'science, nature and environment' started by krtek a houby, Jan 26, 2016.

  1. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    It is true that life around hydrothermal vents isn't particularly intelligent, but given a lot more time and perhaps a lot more vents, I don't see why many of those problems could not be overcome once an environment rich in life has evolved. And once they have been overcome, those living there might equally see the idea of complex intelligent life out of water as immensely challenging.
     
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  2. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Ta for the links. Will give them a proper read, but the immediate impression is that the questions are flawed. The questions asked are essentially: 'how could they do the things we do?' But in reality, they would be doing all kinds of things that we haven't even guessed at, and much or most of what we do wouldn't be relevant.

    So perhaps we need to start from the other direction, which I admit is really hard - what kinds of problems might they face, and what would be available to them to solve those problems? A bottom-up approach.
     
  3. EastEnder

    EastEnder Brixton Barnacle

    I certainly hope that's the case, especially given how many water worlds without atmospheres exist. In some ways seeing how permanently water bound creatures evolved to become intelligent & technologically sophisticated would be even more mind blowing than a land based equivalent.

    I reckon Europa's got tremendous promise in that regard - it'll escape the fury of the expanding sun, and given that its primary heat source is tidal friction from its orbit of Jupiter, it could potentially remain habitable for some form of life for many, many billions of years long after the Earth is a burnt cinder or a frozen husk.
     
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  4. DotCommunist

    DotCommunist my world is fire and blood

    gills behind the ears, radically redesigned cardiovascular system and respiratory system. Nictitating membrane for the eyes, sphincters for the nostrils and ears. The bumhole can take care of itself, it usually does. Altered sweat glands to produce some sort of oil covering. Then we can all live under the sea
    [​IMG]


    so far we haven't even cured cancer yet, so these biomods may be some way down the line
     
  5. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    NASA plans to send a probe to Europa by 2031 to see if they can find life. I hope they get the funding and I hope I'm still around when they get the results.
     
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  6. NoXion

    NoXion Give me space communism or give me death

    Whatever the problems turn out to be, no doubt tools of some kind or another would be useful. Here's a video of a little octopussy using a coconut shell as a portable shelter/shield/carapace. It's not the sort of thing we would use for that purpose, but I'd say that's close enough to "tool". No doubt smarter organisms would use more sophisticated strategies.
     
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  7. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Yes, I have no problem with attributing tool-use to octopuses. Dolphins use tools as well - sponges on their snouts to forage - but they didn't just evolve in the oceans, so not sure they'd count.

    I think the scenario EE is envisaging is one in which life evolves using energy from within the planet/moon rather than using energy from the star it's orbiting. That does widen the scope of potential habitable zones considerably and also widen the possible timeframes. I think that's a very interesting avenue to explore - much attention is focused on looking for Earth-like planets in Earth-like orbit conditions, which is natural enough while we only know of life on Earth, but potentially the range is far greater than that. And if you live at the bottom of a deep ocean, where all the life you know of is also located, but have developed an intelligence that seeks to explore, would you even bother looking up? Would exploration into the planet perhaps be your first area of interest? Or is the idea of exploration overrated and a bit human-centric? Just cos you're clever, that doesn't necessarily mean you want to move from the place you're best-suited to be in. It might mean quite the reverse - Are you mad? Don't you understand evolution? We evolved to live here, ffs. Just look at these tentacles!
     
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  8. NoXion

    NoXion Give me space communism or give me death

    If they're at all curious about the world they live in as a whole, then they're going to find the boundaries of it. It may well stop there, given the strong possibility of a low risk-reward ratio for passing it. I wouldn't be at all surprised if it turns out that most intelligent aquatic life never leaves its home world. Which could make it very hard for us to detect without actually sending something to the body in question. If it's open ocean then spectroscopic analysis of the atmosphere might be possible, but what if it's a world like Europa and they're all under ice?
     
  9. weltweit

    weltweit Well-Known Member

    I wonder how different life here might have been if the dinosaurs had not been made extinct?
     
  10. EastEnder

    EastEnder Brixton Barnacle

    I've heard it speculated by some that life would still have evolved towards smaller, more nimble, ultimately intelligent creatures, but possibly more reptilian in nature - anyone remember 'V'?

    Personally I think that's an overly anthropocentric perspective, almost arrogant in its assumption that evolution would inevitably end up with a human-like being at the end. The simple answer is that it's impossible to say. Evolution does not tend towards intelligence, it merely favours the most adaptable. Given that the dinosaurs were the dominant species for far longer than the time elapsed since their extinction, it's not at all implausible to suggest that perhaps they would've just kept on evolving into different forms of dinosaurs. Crocodiles were alive contemporaneously with dinosaurs, and they've not really changed much since!
     
  11. fishfinger

    fishfinger تپلی

    Dinosaurs were not exactly made extinct - Just the big ones. Small dinos went on to become birds.
     
  12. EastEnder

    EastEnder Brixton Barnacle

    Actually that's a bit of a misconception - birds evolved from dinosaurs, but were around for a very long time before the demise of the dinosaurs. Contemporary birds are the descendants of the ancient birds that survived the extinction event. Don't forget that "dinosaurs" is an extremely broad classification that spans about 165 million years. Birds first evolved from predatory dinosaurs something like 150 million years ago. So some dinos did go on to become birds, it's just that they did it long before the big dinos got whacked.
     
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  13. fishfinger

    fishfinger تپلی

    Yes, my post was a little simplistic. :)

    I agree that "dinosaur" covers a wide variety of animals and a very long timespan. I know there were a lot of changes to the climate and atmosphere over a long period, making it increasingly difficult to support larger animals, with the KT event being the last straw. So it wasn't just large dinos but pretty much all larger land animals (and plenty of water dwellers) that appear to have been finished off.
     
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  14. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Agree with the general thrust of this, but it's a contested idea whether or not evolution has direction. Certain things, including intelligence, are selected again and again, and there are lots of incidences of convergent evolution. There is a theory proposed by the biochemist Addy Pross that more complexity among replicating molecules produces more stable systems than less complexity, which could give a direction to evolution towards complexity. Contested idea, though, and as Stephen J Gould liked to point out, the vast majority of life forms on Earth are and have always been single-celled organisms - us multicells are in the minority.

    Regarding birds, I don't know of any particular taxonomic reason not to consider them to be dinosaurs.
     
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  15. ferrelhadley

    ferrelhadley colourless green ideas sleep furiously

    Big brains are incredibly expensive. Fossil and genetic records indicates that Homo neanderthal was a population of 70 000 individuals across all of Eurasia. Until the arrival of "behavioural modernity" about 70-50 000 years ago we seemed to be a minor part of the ecosystem. Earth is likely a freakishly unusual planet and our intelligence is likely freakish unusual on that kind of planet.
     
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  16. AuntiStella

    AuntiStella not well liked

    I seem to remember Dawkins saying similar. That the only reason we don't have the same word for birds and dinosaurs is because of historical circumstances. They are the same group of animals.
     
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  17. stuff_it

    stuff_it stirred the primordial soup

    What about the 'dark forest' theory, that all the aliens are dead or have STFU to avoid being extincted by bigger boys.
     
  18. DotCommunist

    DotCommunist my world is fire and blood

  19. stuff_it

    stuff_it stirred the primordial soup

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  20. DotCommunist

    DotCommunist my world is fire and blood

    I forgot about three body problem and how it was due a sequel :cool: To the torrentbay!
     
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  21. stuff_it

    stuff_it stirred the primordial soup

    All three are now out in translation. :thumbs:
     
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  22. EastEnder

    EastEnder Brixton Barnacle

    Intuitively I would tend to assume that intelligence should be a selected feature, although I can see it being more of a sliding scale. One would think that an intelligent creature would have a greater chance of survival than a less intelligent one, but what if the cleverer of the two isn't massively cleverer? And the less clever one is better physically adapted to cope with a big environmental shift? For example, our shrew like ancestors that survived the KT extinction most probably did so because they were very small & could hide in underground burrows, eating tubers & worms, not because they were all that clever. Equally, a clever T-rex would've perished with all the rest. So I think maybe one factor in favouring intelligence is a sufficiently calm environment - not too calm, cos you need to mix things up a bit, but not so disruptive that physical adaptability trumps intellectual adaptability. It would make sense to me that you need a long period of only moderate environmental changes to allow intelligence to be selected for, and to finally reach the point where the creature is intelligent enough to overcome environmental shifts that its physiology alone couldn't cope with - such as modern humans.

    And on the issue of complexity of replicating molecules, I don't know if it's relevant, but I've always found it interesting that some of the simplest, oldest creatures have some of the more complex DNA - there's a fern with 1260 chromosomes, whereas we have 46! Kinda feels to me like nature tends towards efficiency over intrinsic complexity!
    Absolutely, they are modern day dinosaurs. I just get a bit pedantic when it's suggested birds evolved from dinosaurs because it can give the impression that classical dinos, like T-rex's turned into little birds, when in reality birds are a specialised form of dinosaurs that evolved roughly 90 million years before the bulk of the dinosaur species were wiped out.
     
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  23. kabbes

    kabbes "A top 400 poster"

    Dinosaurs would have assumed size and strength were the best survival factors and intelligence was rubbish. And they were right about that too for a lot longer than we have been thinking intelligence was best.
     
  24. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    Without the shock extinction event, life may very well still look mostly rather like it did 65 m years ago. But various ecological niches have produced conditions in which the calorific cost of high intelligence is worth paying. Clever crows are effectively dinosaurs that have evolved to be smart.

    There was another hugely important event 55 m years ago, the Paleocene-Eocene Thermal Maximum, during which there was rich plant life at the poles. This marks the time mammals started to diversify into the various forms we see now. It also marks the time when songbirds evolved, with their rather specialised form of intelligence. If the big dinos had still been around at that time, they would not have been unaffected by it.
     
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  25. littlebabyjesus

    littlebabyjesus one of Maxwell's demons

    We're also really biased in our view of all this. An objective two-word summary of life on Earth from an alien report could well be 'mostly bacteria'.
     
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  26. ferrelhadley

    ferrelhadley colourless green ideas sleep furiously

    Evolution has been sometime described as "long periods of boredom punctuated by short periods of terror"(originally about war)
    However the KT is still a little controversial with some going for the Deccan Traps caused hyperthermal that was underway as a cause and others going for the "press push" model that the two combined to hammer the big species.
    While some burrowers got through it, so did crocodiles and birds. The mammals that got through were likely a bit bigger than shrews. They did not actual dominate afterwards, birds seemed to have done best, mammals kicked on during the Eocene.
    Earths evolution seems to be that after long periods of diversification you get a big wipe out event and an new restarting. This seems to wipe clean the large animals and allows the smaller ones who have made "the most" progress to take the mantle of dominant vertebrate life form, this is what happened to allow dinosaurs after the Permian Triassic uber die off.
    There is a theory that Earths rock weathering\carbon system is critical here. We have had a remarkably stable climate in spite of the Suns energy increasing about 30%. Mostly liquid water. Much\most\all of the planet froze during the Cryogenian when ice sheets reached the equator. When that ended during the Ediacaran we see the first multi cellular life, that is followed with that multi-cellular life developing hard parts and sensors in the Cambrian leading the famous Cambrian explosion.
    Then over the next 520 million years we see life diversify and radiate before disaster strikes, often related to the carbon cycle heating or cooling the planet, then more diversification and increasing complexity of nervous systems. This is sometimes talked about as an evolutionary pump.
    We think we see a miniversion of it over the past 3million years as the swings from glacial to interglacial created a constant flux of niches that the upright apes became adept at exploiting by carrying their massively over specced brains.

    Till BOOM about 70 000 years ago modern behaviour arrives and everything goes into over drive.

    A plant whose crust is just perfect for continents above an ocean, enough vulcansity for a cabron cycle to regulate temperatures for 4.5 billion years but enough variability to create the pump, stabilising uber companion in the Moon, gas giant that swallows most stray asteroids in Jupiter and a whole host of over stars may have come into alignment to make this the perfect biological laboratory for "punctuated equilibrium" evolution.

    Over our life times we will have many more answers. But is one hell of a journey finding out.
     
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