For creationists who depend on gaps in scientific knowledge, research into the origin of life presents a recurring difficulty: scientists keep finding ways to investigate those gaps. One question is when the early Earth became sufficiently stable for the chemistry preceding life to persist. Producing potentially useful molecules would have achieved little if repeated impacts then destroyed them. Before life could gain a foothold, its chemical ingredients needed somewhere they could survive.
A new study by Oleg Abramov and colleagues, published in Nature Communications investigates that problem using a three-dimensional model of impact heating. The researchers identify approximately 4.33 billion years ago as a particularly favourable time for persistent prebiotic chemistry. That places the proposed opportunity billions of years before the entire universe supposedly appeared in the chronology of Young-Earth creationism.
The emerging picture scarcely resembles a world prepared as a comfortable home for living things. Early Earth endured bombardment by asteroids, comets and leftover planetary building blocks. As that bombardment declined, regions of the shallow crust could remain cool enough for fragile molecules to persist. Around 4.4 billion years ago, the simulations begin to show environments that escaped subsequent reheating above the study’s specified threshold.
There is an interesting complication: impacts could also help create opportunities for life’s chemistry. Water circulating through heated, fractured rock can produce hydrothermal environments with sources of chemical energy. The researchers therefore sought an overlap between enduring cooler regions and continuing hydrothermal activity. Their proposed favourable window represents a changing balance between destructive heating and potentially useful geological activity, with no foresight required.
The distinction between opportunity and occurrence matters. This study does not demonstrate that life began 4.33 billion years ago, nor establish that an “RNA world” actually existed then. It constrains the thermal conditions under which such a proposed stage could have persisted. The date also depends on assumptions about bombardment: a lower estimate of the incoming mass moves the favourable window earlier, towards 4.4 billion years ago.
For creationism, the difficulty extends beyond the enormous timescale. An unanswered question about life’s beginnings is being broken down into physical conditions that researchers can calculate, compare and challenge. Uncertainty remains, but uncertainty supplies questions for further investigation; it supplies no evidence for a supernatural designer. Here, another part of the origin-of-life problem becomes a tractable question about the history of a changing planet.
