Assertion 3.4: Meteorite bombardment of the early Earth would have destroyed any new life, and there is too little time between the bombardment and the first signs of life for life to have come into existence naturally.
Analysis:
(i) Life may have evolved in areas which were protected from the worst of the bombardment, for instance, near deep-sea vents (Fry 2000:119). Some prebiotic synthesis may also have been accomplished in space, and then delivered to the Earth by meteorites, shortening the time needed for the origin of life.
(ii) Even if life did need to arise comparatively rapidly, this would not refute abiogenesis; all it would mean is that researchers must evaluate mechanisms that operate appropriately fast. And, in fact, we find that many proposals for the origin of life do involve rapid mechanisms. Stanley L. Miller (of the famous Miller-Urey experiments) even opines that "a period of perhaps 10,000 years for [the origin of life] is not impossible" (Miller 1992:3).
References
Fry I. 2000. The Emergence of Life on Earth: A Historical and Scientific Overview. New BrunswIck: Rutgers University Press.
Miller SL. 1992. The prebiotic synthesis of organic compounds as a step toward the origin of life. pp. 1-28 in Schopf 1992.