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What is good time for Earth to begin new evolutionary cycle?

  1. Jul 6, 2015 #1
    Humanity exctincted and after XXX years Earth is populated by "new" humans. How long could it take if exctinction happened in 2130?
     
    Last edited: Jul 6, 2015
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  3. Jul 6, 2015 #2

    HallsofIvy

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    I have no idea what you could mean by a "new evolutionary cycle". Evolution is continually happening.
     
  4. Jul 6, 2015 #3
    Depends on how close the nearest relative is.
     
  5. Jul 6, 2015 #4

    Drakkith

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    That's impossible to answer since it depends a great number of variables, some environmental, some biological. To throw out a random guess, if we assume that one population of our nearest relative, Chimps, evolve to become similar to us, I'd guess around 5 million years at minimum. That's approximately how long ago our two lineages split from each other. But that's assuming this population of chimps is subjected to environmental pressures that favor an evolutionary path similar to our own.
     
  6. Jul 6, 2015 #5
    If humans became extinct, I think that it's likely that nature would will find another cunning plot which is less likely to go extinct and will not necessarily resemble humans.
     
  7. Jul 7, 2015 #6
    I am sorry that I didn't specify this. I am writing plot about all known mammals, reptiles, bird, fish etc. going exctinct. Humans are already colonising other planet so rest of them move there to start new life. By that time Earth is lifeless. Many many years after (That's the number I am looking for, it doesn't need to be 100% right but atleast beliveable) there is new life rising on Earth resulting in primitive tribes of new human race.
     
  8. Jul 7, 2015 #7

    Ryan_m_b

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    Humans would not evolve again if we had gone extinct. If you mean sentient tool using race well if there is no life on Earth then your answer could be in the billions of years. There's really no way of answering it beyond a ballpark figure of "an extremely long time".
     
  9. Jul 7, 2015 #8
    Hmm right. That's too long. So in other hand, how can survivors go primitive again? Let's say some of them survived exctinction but I can't see how can they lose their ability to read, count etc. after many generations later.
     
  10. Jul 7, 2015 #9

    Ryan_m_b

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    That's a very different scenario and is much easier to imagine. If civilisation falls in some way then it's easy to see a return to hunter-gatherer lifestyles. Without millions of educated, specialised labourers modern society falls apart. What use it knowing how to use a computer if there's no power? How does being a marine biologist help you string together shelter? People would fall back to the basics of learning how to get food and shelter. The first generation would retain a lot of their knowledge and some might be able to apply it (mechanical engineers for example), but the second generation would only adopt the skills necessary to survive. By the fourth generation, when all the first are dead, technological society is little more than a story. Something no one they've ever known has experienced. It could take a great many generations for populations to get up to the point where they could organise together and try to restart a technological civilisation, but whether or not they would is another matter.

    In terms of a number figure...well it took us ten thousand years to go from primitive agricultural communities to today. But like evolution history isn't a linear path. If you had books and other relics that showed you what might be and pointed the direction to go....perhaps the reboot time would be measured in centuries, or millennia.
     
  11. Jul 7, 2015 #10

    HallsofIvy

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    Frankly, you seem to have a poor idea of what "evolution" is. Evolution results in species that are good for the specific environment in which they find themselves. There is no reason to believe that anything resembling humans would ever evolve again.
     
  12. Jul 7, 2015 #11
    Thank you that will help me a lot. I also want to ask how will Earth's landscape and biomes change in thousand years? No nuclear weapons caused exctinction. I want to make it that way that cities and everything else is burried under dirt and people are living in terramorphed mountains, forests, near rivers etc. Keep Earth same but bit different.
     
  13. Jul 7, 2015 #12
    [Nothing like us will ever evolve again, that's absolutely true, however, intelligence seems to have a general direction in evolutionary terms. Animals today are smarter than animals of previous geological periods, because it's such a powerful evolutionary advantage, many of what we used to think make us special has arisen many times independently: We've discovered tool use and production in other animals. We've discovered advanced grammatical languages in other animals. We've even discovered exceptionally high levels of sentience in some birds.

    I would think if you wiped the earth clean and started over, intelligence would arise again, but creatures like us are probably very rare.

    If you are thinking more in terms of humans devolving and starting up again, that's more likely. Our society could fall apart easily, it's happened before. After the fall of Roman civilization, it took a thousand years to get back to where they were, constant fighting kept any sort of reunification. With the weapons our distant relatives could access, if our civilization fell, that fighting would probably drag out longer and do much more damage to our population.

    When thinking about really long time periods and humans, remember that we haven't stopped evolving either. In five million years, there won't be any humans anymore. There will be a species that are very similar to, but very much not humans. In fact, I predict we'll start calling ourselves something else in only a few hundred years, as our intellect has given us the ability to design our own evolution through genetics.
     
  14. Jul 7, 2015 #13
    It will be surely interesting. Such a shame none of us will be not able to see it. Anyways thank you for your response it clarified some stuff in my plot!
     
  15. Jul 7, 2015 #14

    DaveC426913

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    This is tantamount to saying that, any planet that is hospitable to life will likely evolve to intelligence. This is not the general thinking. Most arguments suggest that, among life, intelligence is probably quite rare.
     
  16. Jul 7, 2015 #15
    I didn't explain myself correctly. I believe that intelligence like dolphins, dogs, crows, chimps... would arise again, but we are something special.
     
  17. Jul 7, 2015 #16
    There are 7 billion people...living in a variety of climates, ecosystems. We are incredibly adaptable.

    'If' there was some variable that wiped us out, then it would most likely wipe out at least all macro life including all mammals of any size.

    The answer. Nobody knows. Evolution doesn't move towards a goal...there are just trends.

    Intelligence isn't magic. It evolved on Earth. My thinking is that the division in life isn't between intelligence and non intelligence but between single cell and more complex organisms. Once complexity evolved then intelligence may arise (or not) as a trait like any other...size, adaption to terrestrial life, mobility, etc. again, it's not magic. At some point it is just a matter of circumstance as to what phyla develops more complex nervous systems...corvids in birds, cephalopods in molluscs, humans and in mammals. Any of these then may go off on a tangent to develop more intelligence.

    This why I think intelligent in the Universe is common. Life is just chemistry. ...complex life at least one in every millionth star which would mean quintillions of intelligences. Personally I think intelligence is even more common than that. One planet around every thousandth star. Sextillions of intelligences.
     
  18. Jul 7, 2015 #17

    DaveC426913

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    Same thing applies. Dolphins crows and chimps are intelligent enough, even if they haven't had a chance to develop tool-usage.
     
  19. Jul 8, 2015 #18

    Ryan_m_b

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    What does "terramorphed" mean? It really depends on what this apocalyptic event was. How was civilisation killed off in this scenario? World war? Asteroid impact? Supervolcano eruption? Plague? Over 1000 years not much would change if humans were to just disappear other than some fairly noticeable reforestation.
     
  20. Jul 8, 2015 #19
    If humans had the technology to 'terramorph' then not much would change. That takes engineering beyond what we have so they would also have technology to build transportation, communicate, etc.

    As a geologist I really don't envision anything seriously hampering the position of man on Earth. If 1% of the population survives we'd be back up and humming along as a species in few centuries. We might actually advance quicker in the sciences and technology than if no disaster.
     
  21. Jul 8, 2015 #20
    From a purely natural point of view, I'd agree. Humans are very adaptable and will only fight each other to the point where it becomes not worth it anymore, so once the population is small enough that there are enough resources to go around, our spats will be small and isolated and the population would slowly recover...

    But that's making a very big assumption that we are still at the top of the food chain. The only way humans will go extinct short of a planet-killing event, is if something starts exterminating us: such as a military AI gone haywire.

    In almost all doomsday scenarios there is a terrible event, but then, it's over. An asteroid hits, we have a nuclear winter... then it's over. We have a nuclear war, another nuclear winter... then it's over. We have a financial and societal collapse... then it's over. The only sure-fire way to kill us all is a continuing threat like an invasive "species."
     
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