The Creation Explanation
|Life -- Miracle, Not Accident|
Significant Enzyme Research
Reports of work with an E. coli strain lacking the enzyme a-galactosidase indicate that under special conditions the strain could undergo a series of five mutations which restored the ability to digest lactose. It is reported that a floating or inactive gene was transformed by the mutations so that it could code for the production of an enzyme possessing some ability to metabolize lactose.26 This is interpreted as the production of new genetic design information by means of random mutations and natural selection. However, more research will be required to determine exactly what has happened in this case. One important question is, was the floating gene one that was originally designed to code for the production of the enzyme but deactivated by a few deleterious mutations?
Another recent investigation dealt with a bacterium with is able to extract needed nitrogen from a two-carbon compound called acetamide. Mutant strains were obtained in which enzyme responsible for the nitrogen metabolism has been modified so that it is able to use the four-carbon compound butyramide, a five-carbon compound, valeramide, and the even larger molecule, phenylacetamide.27 Apparently the enzyme molecule has been modified so as to lengthen a groove into which the longer-chained amides can fit. But the basic function of the enzyme, i.e., the use of amides as a source of nitrogen and/or carbon, remains the same. Furthermore, the authors point out that the special bacterial strains which they have developed in the laboratory are inefficient because their modified enzymes are constitutive (i.e., have no controls and thus are produced whether needed or not). These bacterial strains could not survive in a natural environment. Thus a model for natural origin of the altered enzymes was not demonstrated.
26. Campbell, John L., et al., Proceedings of the National Academy of Sciences, Vol. 70 (1973), pp. 1841-1845.
27. Betz, Joan L., et al., Nature, Vol. 247, 1 Feb. 1974, pp. 261-264.