How could human beings move out of Africa with so many large, fierce animals?

Discussion in 'General Science & Technology' started by geek, Dec 6, 2017.

  1. Gawdzilla Sama Registered Senior Member

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    And, of course, the Chernobyl earthworms are an average of 17% larger than before the accident.
     
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  3. DaveC426913 Valued Senior Member

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    Well, they're not being hunted by anglers, are they?
     
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  5. Write4U Valued Senior Member

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    In fact it was humans who drove them to near extinction, until they became an "protected species".
    The same is happening now to Elephants and Rhinos.

    Humans are the ultimate predator. We can kill things from miles away.
     
    Last edited: Dec 7, 2017
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  7. Write4U Valued Senior Member

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    Right, humans were forbidden to enter the danger zone. Lots of insects seem to be immune to radiation also.
     
  8. Gawdzilla Sama Registered Senior Member

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    Nope, just some guy named "Tatapoulis".
     
  9. Gawdzilla Sama Registered Senior Member

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    The mutation rate of the alpha predator, wolves, is twice the normal rate.

    Now we get to the hard numbers. Chernobyl wolves have mutations at the rate of 0.04% vice 0.02% for wolves outside the area. Wildlife is enjoying the human-free zone.
     
  10. Write4U Valued Senior Member

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    Interesting, and might have some possible implication on the evolution of human brain. An exposure to radiation causing a mutation in human DNA.
    Apparently at a certain time there was a fusion of two hominid chromosomes into one large human chromosome.
    This is why humans are distinct from other hominids by having one less chromosome .

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    http://www.evolutionpages.com/chromosome_2.htm
     
  11. iceaura Valued Senior Member

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    Nothing is immune to the radiation, or undamaged by it.

    What we see demonstrated is that the effect of human settlement on the ecology of a region is worse than a nuclear explosion.
     
  12. Write4U Valued Senior Member

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    I agree in general that radiation breaks down or damages molecular structures. But at nano scales radiation may also be responsible for the creation of bio-chemical structures such as polymers. According to Robert Hazen, this may even occur in cosmic clouds. See ;
    For the formation of these type of these pre-biotic chemical reactions start the clip at 28:40 for the possible origins of polymers through radiation in cosmic clouds.



    And then I ran across this remarkable article about Fruit flies.
    Fruit flies are often used in radiation experiments, and even as they display genetic alterations they don't necesarily die, but become grotesquely distorted. But also
    https://www.belmarrahealth.com/radiation-increases-life-expectancy-of-fruit-flies-are-humans-next/

    If true, this hints at some remarkable properties of simple insects and of tardigrades.

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    https://www.nytimes.com/2016/09/27/science/tardigrades-water-bears-survival.html

    I totally agree, at least in the short term (relative to millenia)
     
    Last edited: Dec 8, 2017
  13. exchemist Valued Senior Member

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    I'd be very sceptical indeed about the fruit fly radiation findings being applicable to long-lived creatures. A long-lived organism seems to me far more likely than a short-lived one to be prone to illness caused by genetic damage, e.g. cancer.

    I don't imagine cancer is a significant cause of death in fruit flies.
     
  14. Write4U Valued Senior Member

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    Nor of tardigrades, those are tough little creatures. And then there are the extremophiles.
    Though it seems that sufficient cell damage can lead to cancer in those micro organisms.
    https://link.springer.com/article/10.1007/s00253-012-4642-7
     
    Last edited: Dec 8, 2017
  15. Write4U Valued Senior Member

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    The variety of life just boggles the mind. I can well understand the propensity for people to attach mystical properties to life and living creatures.

    This is why I found the Hazen lecture so fascinating. The concept of probabilities of all kinds from the combinatory richness of time and space really expanded my view of the universe and its inherent potentials.
     
  16. sweetpea Registered Senior Member

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    Talking of things surviving radiation... reading about the Ginkgo trees that survived the nuclear blast of Hiroshima made me wonder, would they have survived a ''Neutron Bomb''?
    The tree in the picture was just under a mile away from the ''hypocenter'' of the blast.

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    https://kwanten.home.xs4all.nl/hiroshima.htm

    http://www.bbc.co.uk/news/uk-england-manchester-29920359
    ----
    And, talking of tardigrades... they have been exposed to space:
    http://www.bbc.co.uk/nature/12855775

    https://www.newscientist.com/article/dn14690-water-bears-are-first-animal-to-survive-space-vacuum/

    And, ahem... http://www.sciforums.com/threads/bug-in-space.159673/
     
    Last edited: Dec 8, 2017
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  17. Gawdzilla Sama Registered Senior Member

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    The OP's question is a little odd, given that hominids have survived in "lion country" for seven million years or so.
     
  18. spidergoat Valued Senior Member

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    And hunted them.
     
  19. Gawdzilla Sama Registered Senior Member

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    Yep, but didn't extinct them. Enough of each branch of hominid lived long enough to pass along their genes to successors. OP seems to think that large predators preferred hominids over all other critters. Most of those "competitors" couldn't climb trees.
     
  20. Write4U Valued Senior Member

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    Cause they're smarter than the average lion.
     
  21. spidergoat Valued Senior Member

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    What I meant was that humans hunted lions. Humans were an apex predator, in spite of their relative weakness and lack of tooth and claw.
     
  22. Gawdzilla Sama Registered Senior Member

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    When did humans hunt lions. I've seen lions avoid Masai, but they had spears and the lions were conditioned to avoid them. How recent that kind of thing is is open to speculation.
     
  23. Xelasnave.1947 Valued Senior Member

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    I think they left to get away from the lions.
    Alex
     

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