Case Study: Catholic Perspective on Evolution -- last page

Current theoretical developments*: Over the past ten years, several major developments in research have left the theoretical picture highly unsettled. These are too complex to explain in detail here, but they are worth noting in brief.

From the mid-1920's until the early 1970's, scientists generally believed that man evolved gradually from a small ape-like creature called *Australopithecus*. As we mentioned earlier, this animal lived more than a million years ago and its fossils showed some human-like characteristics. It may have walked upright, at least some of the time, and its teeth approximated those of man. Moreover, researchers often found stone tools scattered among its fossils.

The theory during these decades held that some form of *Australopithecus*, enjoying relatively free use of its hands, developed tool-making, and this skill gave rise to an ever-larger brain through the forces of natural selection. Countless drawings in magazines and textbooks showed the furry *Australopithecus* standing next to *Homo erectus*, his distant evolutionary offspring.

But in the early 1970's researchers were astonished to discover forms of *Homo erectus* from almost two million years ago, complete with tools. In other words, man had lived alongside and even before some forms of *Australopithecus*. Most likely, it was he who had fashioned the tools found among the ape-man fossils. This discovery threw into question, to say the least, the evolutionary relation between the two forms of life. As of this writing, the problem is still being debated.

Around this time, several prominent paleontologists went on record to question the prevailing theory of gradualism, the well-known Darwinian position of evolution through natural selection. (High school and college textbooks taught this as virtual dogma up until recently.) These researchers claimed that, contrary to Darwin's predictions, the fossil record does not show gradual transitions between species. On the contrary, they maintained, the evidence shows extreme stability of form. Species seem to appear suddenly on earth, remain virtually unchanged for
millions of years, and then disappear just as abruptly.

What could account for this phenomenon? Current theory holds, among other positions, that major genetic alterations resulted in relatively sudden appearances of new species. This genetic leap is called "macroevolution." Meanwhile, within species at any given time, the forces of natural selection were at work effecting minor alterations of structure --like reshaping of finches' beaks, noted by Darwin. This process is called "micro-evolution." How genetic and environmental forces have interacted to produce new species is, at this point, an open question.

Our purpose here has been to demonstrate the dynamic nature of scientific inquiry. Even these few brief sketches show how evolutionary thinking has undergone an evolution of its own and still does. Science has many uncertainties and very few dogmas. This uncertain quality accounts, in large measure, for the fascination scientists find in their work.

Catholics have nothing to fear from science's honest inquiries, honestly explained. On the contrary, every new discovery is a source of wonder and a reason for giving praise to God. Of the Creator, we can say with St. Paul, " ... from the foundations of the world, men have caught sight of His invisible nature, His eternal power and His divinity, as they are known through His creatures" (Rom 1,20).