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Earth Worms Science

Ancient Worms May Have Saved Life On Earth 54

sciencehabit writes You can credit your existence to tiny wormlike creatures that lived 500 million years ago, a new study suggests. By tunneling through the sea floor, scientists say, these creatures kept oxygen concentrations at just the right level to allow animals and other complex life to evolve. The finding may help answer an enduring mystery of Earth's past. The idea is that as they dug and wiggled, these early multicellular creatures—some were likely worms as long as 40 cm—exposed new layers of seafloor sediment to the ocean's water. Each new batch of sediment that settles onto the sea floor contains bacteria; as those bacteria were exposed to the oxygen in the water, they began storing a chemical called phosphate in their cells. So as the creatures churned up more sediment layers, more phosphate built up in ocean sediments and less was found in seawater. Because algae and other photosynthetic ocean life require phosphate to grow, removing phosphate from seawater reduced their growth. Less photosynthesis, in turn, meant less oxygen released into the ocean. In this way, the system formed a negative feedback loop that automatically slowed the rise in oxygen levels as the levels increased.
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Ancient Worms May Have Saved Life On Earth

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  • by Chrisq ( 894406 ) on Thursday August 07, 2014 @04:19AM (#47620859)
    Isn't that the plot of Dune?
  • Praise our overendowed saviors for keeping us from going extinct before we started, but where were they when the lizard men took over, hmmm?

    • Praise our overendowed saviors for keeping us from going extinct before we started

      Why would we have become extinct? Isn't one of the major results of evolution that life adapts to the environment in which it lives? I saw nothing in the article to suggest that it would have been impossible for life to adapt to cope with higher levels of oxygen.

      • Increased oxygen levels can cause big problems in part because it's generally toxic, but mainly due to it's combustion enhancing properties. The more oxygen there is in the air, the more severe any forest fires become until you get to the situation where a lightning strike can ignite the whole atmosphere. I'd imagine that the increase in fires would probably limit just how much oxygen the atmosphere could contain (i.e. a stabilising feedback loop).
        • Increased oxygen levels can cause big problems in part because it's generally toxic, but mainly due to it's combustion enhancing properties.

          It is only toxic because we have evolved to deal with air that is ~20% oxygen. Were the content 15% or 25% we would have evolved to cope with that. As for combustion enhancing firstly that does not really apply ~500 million year ago because all life was underwater where combustion is somewhat harder. Secondly the naturally combustable material today all comes from plants hence evolution would presumably have resulted in less combustable natural materials or better fire resistance because, as you point out,

  • Saved the earth (Score:5, Insightful)

    by Thanshin ( 1188877 ) on Thursday August 07, 2014 @06:00AM (#47621181)

    Every single creature that has ever existed is responsible for the current precise status of the Earth.

    If an ancient civilization traveled half a billion years to the past and killed a single bacteria, the present wouldn't be exactly the same. Maybe the difference would be small, but it's much more probable that the impact of that tiny change, and its accumulated consequences century after century, billions of generations of bacteria later, would have changed everything.

    A single misplaced atom could be responsible for the non-existence of the troglodyte who was to be the ancestor of the guy who wielded the weapon that killed the great grandfather of the guy who discovered how to make fire, delaying the discovery a few dozen generations, and turning the present into the renaissance.

    • This would be a great idea for a Twilight Zone episode... oh wait...

    • Re:Saved the earth (Score:4, Interesting)

      by TapeCutter ( 624760 ) on Thursday August 07, 2014 @07:07AM (#47621355) Journal
      Not really, the biosphere is a mathematically chaotic system in a state of "dynamic equilibrium" (google it), a single worm/troglodyte is to the biosphere as a raindrop is to the global climate.

      The worm theory is not new, this appears to be more evidence to support it. A similar process helps regulate CO2 today in the southern ocean, algae grows on or near the surface and sucks up CO2 and release O2, the algae attract large schools of krill that feed on it. The algae give off a particular smell when they are attacked, the smell attracts seabirds (and marine predators) who eat the krill by the ton.

      Here's the beautiful part (to a "systems programer"), the birds and whales shit in the water when feeding on krill, the bird shit in particular is rich in phosphorus and iron (from the krill) which fertilises a new generation of algae.
      • I think we can develop a theory for "why chaotic systems develop equilibrium" and I think it would start with concentrations of energy sources. If there is a lot of sediment with nutrients and energy being buried on the sea floor -- it's LIKELY that some organism will exploit it eventually.

        It's interesting to look at (if I remember correctly) the Pleistocene epoch, where for about 50 million years there was no bacteria that broke up and digested falling trees. So we have a lot of coal from this epoch for th

      • I hit Ctrl+F to search through the postings, and almost nobody talks about phosphate. Phosphate is banned in detergents, because it creates algal blooms, and through algal booms it exterminates other life, like predator fish, whose visibility drops to zero, and the ecosystem get out of balance. Plus a lot of them release toxins. But there is word, that when it comes to biofuels, (though you can't trust anything without verification) that algae are the most efficient and fastest growing photosynthetic organi
    • I'm with you to a point. But there's a lot of "parallel" evolution and discovery going on. Two different groups of mammals became bats for instance, and there are numerous examples of nature creating similar creatures to "fill a niche". It was likely any untapped energy source of sufficient quantity and quality will inevitably produce an organism that uses that product. It's almost like predicting the weather by just charting blocks of heat -- a high pressure area of heat will move air masses, you only need

    • Maybe the difference would be small, but it's much more probable that the impact of that tiny change, and its accumulated consequences century after century, billions of generations of bacteria later, would have changed everything.

      Not really, for the same reason that killing one mosquito generally won't make any difference, even though it can produce a whole bunch more; the mosquitoes themselves compete with one another. Taking one out just means less pressure from internal competition. You'd likely have to take out a bacteria while it was the only example of its species to make a significant impact. Bacteria die all the time and another member of the same species is not only likely to end up in the same place but will also have the

      • Maybe the difference would be small, but it's much more probable that the impact of that tiny change, and its accumulated consequences century after century, billions of generations of bacteria later, would have changed everything.

        Not really, for the same reason that killing one mosquito generally won't make any difference, ...

        Two types of analysis:

        Macro view: Killing a few mosquitoes won't affect overall dynamic equilibrium, the next few millennia are more or less the same as viewed from 30,000 ft.
        Micro view: Killing a few mosquitos prevented malaria from spreading to the Berg clan, who became more powerful and wiped out the Valley clan, completely rewriting history for a particular territory of a particular mammal.

        • Micro view: Killing a few mosquitos prevented malaria from spreading to the Berg clan

          Rarely are you going to have a situation where killing literally a few mosquitoes will actually prevent the spread of malaria when people are used to being bitten by them, and not being able to prevent it. You will typically need to destroy large populations. The total biomass involved is relatively small, but it includes many individuals.

    • I've considered this theory, and even enjoyed several stories that illustrate the point. The problem is, it's a narcissistic load of bull. Nature doesn't care what you do. God doesn't care what you do. Sure, we're all invited to the party, but most of us will get by if you don't make it. If you calculate the maximum entropy a single human being can introduce into the universe, you will discover it quickly becomes swamped out. Now I'm not saying you shouldn't live your life in accordance with your own self
    • You really liked that movie didn't you? It's a nice fairy tale but doesn't really hold water at that individual level.

    • Comment removed based on user account deletion
    • So then we need to thank Xenu and his space borne 707 and the alien greys, whites etc for all their contributions to our wonderful earth? No. You are oversimplifying it. There is far more built in redundancy that you realize.
  • This is referencing Doctor Worm by TMBG.
  • Should all patents now belong to the worms?

  • scientists say, these creatures kept oxygen concentrations at just the right level to allow animals and other complex life to evolve.

    And they've regretted it ever since.

  • Isn't this just the anthropic principle at work?

    Yes, the action of these worms kept oxygen levels at "just the right level" for animals and other species to evolve...but isn't it simpler to expect that (lacking these worms, and with I suppose the much-higher oxygen levels) some other feedback mechanism would have eventually kicked in and THEN life would have evolved around that norm instead?

    Obviously, with a sample size of precisely one, it's hard to say.

  • ... the early birds showed up.

  • by TTL0 ( 546351 )

    I thought it was the dolphins the whole time ??!

  • Ancient Worms May Have Saved Life On Earth ...from threadfall?

  • is limit on the raw material. CO2 is a rare gas by comparison. O2=21% of the atmosphere, CO2 = 0.04%. It used to be the reverse, back before photosynthesis evolved.

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