Has the Origins of Human Life on Earth Been Discovered?

Discussion in 'Science and Technology' started by Dryson, Aug 17, 2021.

  1. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    I'm tempted to try that collision in Universe Sandbox.
     
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  2. publiusr

    publiusr Vice Admiral Admiral

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    Hit Venus with Ceres instead—-blow that murk off, spin it up and give it some moonlets
     
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  3. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    Why humans might be among the first civilisations to develop - grabby aliens:



    I think we have to be among the first in this universe as, in a multiverse, developing too late gets you exterminated to make way for expansionist species. Whether we choose to exterminate other, less developed species to allow us to expand remains to be seen. A parallel has happened during colonisation on Earth - for example, the Tasmanians were exterminated by European settlers. One would like to think that aliens will be more enlightened but I wouldn't bet the farm on it.
     
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  4. Brobdingnag

    Brobdingnag Captain Red Shirt

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    Underestimated? I think he said it was infinite.
     
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  5. XCV330

    XCV330 Premium Member

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    It depends on what stellar civilizations would conquer for. Unless species continue to have unchecked population growth, they're resource needs probably taper down after awhile. If anything, humanity's problem may one be negative population growth, for instance. There's always the idea of a war to acquire technology or goods, but trade is easier, and unilke the whole Borg thing.. if a civilization truly has something of tactical value that you don't, it's probably not a great idea to attack them. There are wars for religious conversion, but mostly in history those have been thin veneers as land and resource grabs. Slave raiding? Again possible but unless there is some kind of FTL travel to make such a thing even worthwhile, the next question becomes what can a captured sentient being do that a machine can't, by the time you have the technology to travel.

    My suspicion is that large scale space civilizations probably will not follow an empire, or republic model, being something more like (guesswork) the Minoans or Phoenicians, smaller political entities linked by culture and trade. Xenophobic civilizations will either aggressively maintain their isolation, go the Dyson sphere route, go cold, or park themselves inside an event horizon until this mess is sorted out.
     
  6. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    Some people just want to accumulate as much as they can so they can wallow in their opulence, believing that they are like gods. I could imagine some aliens might be the same.
     
  7. Brobdingnag

    Brobdingnag Captain Red Shirt

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    There's no reason to believe that evolved aliens would be more virtuous than us.
     
  8. Gingerbread Demon

    Gingerbread Demon Stealer of all the cookies in time and space Premium Member

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    Exactly! For all we humans know they could be worse than us. Maybe Capitalists even x1000,000
     
  9. Nerys Myk

    Nerys Myk Worf In the 23rd Century Premium Member

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    [​IMG]
     
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  10. XCV330

    XCV330 Premium Member

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    one thing about the origin of life that i find interesting is the RNA world hypothesis. the question is if there was RNA life why is there none left? there are still examples of life that must be pretty close to the first DNA based life, chemosynthetic archea and bacteria.

    Did the success of the new kind of life do so well that the conditions of life just were not possible? or possibly it could not survive Purple Earth or Snowball Earth (especially the latter). its interesting to ponder whether there is still some sign of rna life out there, lurking in a puddle underground or just viroids
     
  11. Brobdingnag

    Brobdingnag Captain Red Shirt

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    Well, there's competition. Just like Marsupial mammals and Placental mammals are pretty much exclusive or Lemurs and Simians or simply the fact that our branch of hominids have eliminated all the others that existed (it is estimated that there have been between fifty and a hundred of them). Yes, all the other hominids died because one way or the other our ancestors made them. Competiton for survival explains why certain types of life no longer exist, IMO.
     
  12. XCV330

    XCV330 Premium Member

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    but an entire clade of life (or proto life) is something else though, i think. it would be like bacteria not surviving. RNA life, if it even existed, didn't work exactly like what we call life now, but did it compete for the same nutrients? i suppose that would make sense.
     
  13. Brobdingnag

    Brobdingnag Captain Red Shirt

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    Isn't a retrovirus a simple example of RNA life?
     
  14. XCV330

    XCV330 Premium Member

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    no. as I understand it a retrovirus is encoded in DNA, whereas it is theorized RNA life would have been loop strands of RNA. About the closest equivalent would be a viroid
     
  15. Brobdingnag

    Brobdingnag Captain Red Shirt

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    Wrong! A virus is encoded in DNA, a retrovirus is encoded in RNA.
     
  16. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    Pretty much except that retroviruses are considered a subset of viruses.

    A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. It cannot replicate alone but must infect cells and use components of the host cell to make copies of itself.
    Virus (genome.gov)

    A retrovirus is a virus whose genes are encoded in RNA. A retrovirus uses an enzyme called reverse transcriptase to replicate itself. It first reverse-codes its genes into the DNA of the cells that it infects before it uses the host cell to make copies of itself. Examples are the HIV and SARS-CoV-2 retroviruses that cause AIDS and Covid-19.
    Retrovirus (genome.gov)
    Reverse transcriptase - Wikipedia

    The RNA world is a hypothetical stage in the evolutionary history of life on Earth, in which self-replicating RNA molecules proliferated before the evolution of DNA and proteins. The term also refers to the hypothesis that posits the existence of this stage.
    RNA world - Wikipedia
     
  17. Gingerbread Demon

    Gingerbread Demon Stealer of all the cookies in time and space Premium Member

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    Is a Virus a form of life?
     
  18. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    Some say yes; others say no. Life is hard to define - like so many other things we don't understand as well as we might like.
     
  19. Gingerbread Demon

    Gingerbread Demon Stealer of all the cookies in time and space Premium Member

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    Interesting so it's a hot debate then. Why?
     
  20. Brobdingnag

    Brobdingnag Captain Red Shirt

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    I beg to differ, life is usually quite easy to define. Viruses happen to be borderline. The question is at what point does "ordinary" or "regular" matter become "living" matter? It's the same thing about life and death of an individual. In 99 percent of the cases, there's no contest, even a layman can say this person is alive and that person is dead. However, there are always cases that are in the "maybe" zone and that require the opinion of experts who sometimes will not even agree with each other. It's the cases of "when do we pull the plug?"

    Viruses are in that dividing zone. If we ever solve the case of the viruses, putting them unambiguously in "living" or "non-living" groups then there'll be some other beings that will find themselves on the border.