Paleontologist Niles Eldredge refers to it as “the most arresting fact that [he has] ever learned.”1 Many others in the scientific community share Eldredge’s astonishment. What causes their amazement?
Over the last decade or so, paleontologists have assembled a body of evidence indicating that life existed on Earth as far back as 3.8+ billion years ago.2 These life forms were morphologically simple, but biochemically and metabolically complex, single-celled microbes.3
Prior to 3.8+ billion years ago, life could not originate and find permanence on Earth because of hostile conditions caused primarily by frequent asteroid and cometary impacts. Around 3.9 billion years ago, the size and frequency of these impact events diminished. For the first time, oceans and a solid crust became permanent features on Earth.4 Immediately afterward, life appeared on Earth. As Eldredge puts it, “In the very oldest rocks that stand a chance of showing signs of life, we find those signs—those vestiges—of life. Life is intrinsic to the Earth!”5
This sudden appearance of metabolically sophisticated life forms poses problems for naturalistic origin-of-life scenarios. Evolutionary models stemming from naturalism predict that life should appear gradually on Earth, after a substantial percolation period. In contrast, the RTB model for life’s origin sees the sudden appearance of biochemically complex organisms as the fingerprint for God’s creative work.6
The chief evidence for early life on Earth comes from graphite deposits in the 3.8+ billion-year-old rocks found in western Greenland. The graphite’s carbon (measured in the ratio of carbon-12 to carbon-13) indicates that photosynthetic microbes produced it. Recently, however, paleontologists searching for ways to avoid obvious problems in evolutionary models have challenged the evidence for early life on Earth.7
Recent work by Danish geochemists takes much of the sting out of these challenges. These researchers found independent confirmation for life’s residue in the 3.8+ billion-year-old rocks of western Greenland. The uranium/thorium fractionation in these rocks compels the Danish scientists to conclude that photosynthetic microbes must have been present on early Earth.8
As investigators continue to probe Earth’s oldest rocks, the evidence for early life becomes more extensive and diverse. In 1997, paleontologist J. William Schopf marveled that “no one had foreseen that the beginning of life occurred so astonishingly early.”9 No one, that is, from a naturalistic perspective.