Even if the deep borehole isn\u2019t devoid of life, the almost unprecedented quantity of recovered rocky cores will help scientists link shifts in water chemistry and rock types to the few microbes that may eke out a living underground. Studying how microbes survive amid scarce subsurface resources \u2014 perhaps by eating hydrogen and other abiotically formed compounds \u2014 could help sharpen our picture of early life.<\/p>\n

Brazelton in particular is on the hunt for the specific enzymes microbes use to turn hydrogen and small organic compounds into energy. \u201cThe whole idea here is that you have chemistry going on in rocks, and at some point, that chemistry turns into life,\u201d Brazelton said. Those enzymes might just be the knob that helps researchers rewind the evolutionary clock to decipher how the earliest metabolisms came to be.<\/p>\n