Now showing items 1-2 of 2

  • The rise of oxygen and the hydrogen hourglass 

    Zahnle, Kevin J.; Catling, David C.; Claire, Mark W. (2013) - Journal article
    Oxygenic photosynthesis appears to be necessary for an oxygen-rich atmosphere like Earth’s. But available geological and geochemical evidence suggest that at least 200 Myr, and possibly more than 700 Myr, elapsed between ...
  • Skin colour, pigmentation and the perceived health of human faces 

    Stephen, Ian David (University of St Andrews, 2009-11-11) - Thesis
    Many non-human animal species use colour to signal dominance, condition or reproductive status. These signals have not previously been noted in humans. This thesis investigates the effects of skin colouration and pigmentation ...