In his book Origins of Life, Dr. Fazale Rana reviews the extensive indirect evidence for the appearance of primitive life on Earth as early as 3.5 billion years ago (bya), with some indications that it may have appeared as early as 3.8+ bya. The later date is supported by actual fossils, the earlier date by chemical signatures of life (even though the fossils themselves are likely to have been destroyed by various aging processes).
What about finding direct evidence of life such as proteins and amino acids? Until recently, such evidence, where actual remnants of life components were obtained, has come from fragments of ancient protein found in T-Rex dinosaur fossils, dated at 68 million years ago.
New research pushes that date back by almost 200 million years. In a paper published as the cover story for the April 2008 issue of Astrobiology and described in a news release from the University of North Carolina at Chapel Hill, J. Griffith has reported finding cellulose microfibers in samples he took from pristine ancient salt deposits deep beneath the New Mexico high desert. The age of these microfibers has been estimated to be 253 million years old—now believed to be the oldest macromolecules to date that have been directly isolated and examined biochemically.
The ancient cellulose is virtually identical to modern-day cellulose. According to Griffith, even the most primitive life-forms likely had means of polymerizing glucose into cellulose as a structural molecule. As he puts it, “Cellulose is like the bacteria’s house, the biofilm surrounding them.” Plants use “cellulose as their structural entity, and insects changed cellulose slightly to make kitin [sic] of which their exoskeletons are formed.” Because cellulose appears to be highly stable and more resistant to ionizing radiation than DNA, Griffith suggests that in looking for evidence of life on Mars, perhaps a good place to start is a search for cellulose in salt deposits.
For RTB, this research adds to the growing body of evidence that life began very early in Earth’s history, and was complex even in its most primitive forms. It’s the early emergence and complexity that present problems for a naturalistic origin-of-life scenario and that fuel efforts to discover an extraterrestrial origin of life. However, as more is learned, we expect this evidence will further support the validity of the RTB creation model and the agreement between the creation accounts of the Bible and the facts of nature.