Logical Reasoning

PT136 · S4 · Q10 In an experiment designed

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In an experiment designed to show how life may have begun on Earth, scientists demonstrated that an electrical spark—or lightning—could produce amino acids, the building blocks of Earth's life.

The Paradox

Given That Earth's atmosphere had high oxygen, low nitrogen And That lightning only produces amino acids in reducing atmosphere (high hydrogen / low oxy environment)

How Could It Be That Lightning produced amino acids?

Goal

Try to find a way in a high oxy / low nitro atmosphere for there to be a way that lightning could still produce amino acids.

10.

Assuming that the scientists' current belief about Earth's atmosphere at the time life began is correct, which one of the following, if true, would most help to explain how lightning could have produced the first amino acids on Earth?

  1. Correct

    Meteorite impacts at the time

    Why this is right

    This allows for their to be "hotspots" of the reducing atmosphere, even though the Earth's atmosphere was different. If there were temporary bubbles of high hydrogen / low oxygen, then a lightning strike there could have triggered amino acids. (Can you imagine the double-whammy for that spot on Earth? You get hit by a meteorite, and then before the gases from the impact have even had time to disperse, you get hit by lightning. On the other hand, you did give birth to the building block of all life as we know it.)

    Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.

    78% picked this

  2. A single amino acid could

    Doesn't Explain Origin

    This tells us about what a single amino acid could do, if it existed. But we're trying to figure out how it existed in the first place. How could lightning make that first single amino acid, if the environment was wrong? This answer doesn't say.

    10% picked this

  3. Earth's atmosphere has changed significantly

    No Impact

    I'm sure the atmosphere has changed, (C), but we are only talking about one specific version of Earth's atmosphere --- one that was high oxy / low nitrogen, and we're wondering how lightning could have made an amino acid within this environment. You're not telling us how lightning was able to cause an amino acid, in this one particular ill-suited environment.

    5% picked this

  4. Lightning was less common on

    No Impact / Opposite

    The relative frequency of lightning is pretty out of scope. If there was barely any lightning and the atmosphere was wrong, then I would be even more confused about how lightning could have sparked an amino acid. But even if lightning happened all the time way back when, this still wouldn't address the paradox, which is that the atmospheric composition isn't a good match for the conditions lightning needs to make an amino acid.

    1% picked this

  5. Asteroids contain amino acids, and

    Unrelated to Goal

    We need to explain how lightning could have caused amino acids, not just how did amino acids get on Earth?

    7% picked this

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