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The Carboniferous was roughly 60 million years long. And oxygen levels were much higher than today. This showed up in large insects. For example they had dra

• klyrs 5y ago
  Maybe I'm reading too far into this, but are you suggesting that higher oxygen concentration is responsible for larger insects? If true, I'd love to understand why
  • deleted 5y ago
    [deleted]
  • morpheos137 5y ago
    More oxygen works better with less efficient breathing systems.
  • tejtm 5y ago
    Their lung analogs are more like holes/tubes where air can go and maybe slosh around a bit. So there is a surface area to volume trade off point that depends on O2 concentration.
  • btilly 5y ago
    Oxygen is one of two factors allowing for large insects. Ecology is the other. As https://news.ucsc.edu/2012/06/giant-insects.html https://news.ucsc.edu/2012/06/giant-insects.html says, before birds you see a clear correlation between insect size and oxygen level. After birds, the correlation disappears.
  • jjk166 5y ago
    Getting sufficient oxygen is a key limiting factor in metabolism. The more oxygen an animal can get, the bigger an animal can afford to get. And it's not just insects. For example, the ancestors of dinosaurs evolved a highly efficient respiratory system towards the end of the permian period when oxygen concentrations were low, which likely helped them survive the deadliest mass extinction ever. Afterwards, oxygen levels skyrocketed up, and the dinosaurs, who still had their efficient lungs, could take advantage of it and became the giants we know and love. This same system is also key to the ability of modern birds to fly. Insects and other arthropods breathe through their skin, so the amount of oxygen they can get is limited by their surface area, whereas the amount of oxygen they need is determined by volume. Thus for any given oxygen concentration, there is some maximum surface area to volume ratio for insects, and in turn a size limit for any given body plan. This is why, for example, the largest species of tarantulas across multiple continents, despite evolving separately, are all the same size - being big has a lot of perks, but if they got any bigger they'd suffocate.
    • eloff 5y ago
      That's a fascinating angle on dinosaurs and birds I've never heard of before, thanks for sharing!
    • willmadden 5y ago
      Oil is mostly a renewable resource. New oil is made from magma heating the basement rocks of the Earth’s crust. As the rocks heat methane gas is distilled. This combines with carbonates and carbon 14 to form oil. This is why oil wells in Saudi Arabia, Russia, and elsewhere mysteriously refill after being depleted.
      • btilly 5y ago
        Citation needed. Given how much your claim flies in the face of established and widely accepted scientific claims, preferably citations to peer reviewed research. Doubly so for the howler about C14. Oil is notable for its conspicuous LACK of C14, not an abundance of it.
        • willmadden 5y ago
          How do these "established and widely accepted scientific claims" explain why oil wells are filling back up? "Established and widely accepted scientific claims" are often nothing more than political propaganda, in this case propaganda originating with Standard Oil, the Rockefellers, and the even older money that backed that empire. Oil being non-renewable justifies overregulation by governments and price gouging by producers. I'll leave you to do your own research.
          • eloff 5y ago
            > How do these "established and widely accepted scientific claims" explain why oil wells are filling back up? Rocks are variably porous. It wouldn't surprise me at all to exploit a well until production is low, wait a period of time, and find there's small amounts of newly accessible oil there. Oil could maybe get squeezed out of the surrounding rock by the pressure differential crated by removing the oil in the first place. I don't know if that's true though, it's just a theory of mine. The success of fracking lends some credence to it.