Zeal For Truth

In discussing evolution, it is fairly common for Christians to distinguish between micro- and macro- evolution (an example of such can be seen here). Microevolution consists of changes within a species; for example, new breeds of cattle have been developed, but the new breeds are still cattle and not some other species. Macroevolution involves changes so great that that a new species emerges, a scientific theory which is rejected by many Christians that fully accept the idea of microevolution.

However, this is not a distinction that most scientists make. They tend to see all evolution as being the result of the same processes, and consider the difference between micro- and macro- evolution to be simply a difference in scale, as well as something that is a rather arbitrary difference.

As far as I know, the major problems (from a scientific standpoint) with macroevolution are that the support for it in the fossil record is very questionable, and that the actual process of one species evolving into another one has not been observed. The second problem may have just changed. According to an article in The Economist , scientists at Yale have become the first to “create a new biological species in a laboratory by encouraging the sort of ecological isolation that happens in the wild.”

The definition of species the article uses, which is what I learned in my schooling, is “a group of organisms whose members can breed with each other but not with outsiders.” I am not sure whether or not this experiment actually accomplished creating a new species by this definition.

The normal versions of Dr Turner’s phages are able to parasitise four types of bacteria. He and his team, however, found a mutant that could infect two additional species. They cultivated a population of this mutant in one of the newly available species and found that after 15 days it had adapted to its new host so well that it had lost the ability to infect other bacteria. It had thus become effectively isolated, because it could never hook up with individuals from other strains. It could therefore be considered a new species.

In any case, this is a development which merits watching. If science can produce observable examples of macroevolution, Christians may no longer be able to make the argument distinguishing between micro- and macro- evolution that is commonly used today.

[Note: My emerging impulses series is not finished and will likely return next week]