Case Study: Catholic Perspective on Evolution #7

Species classification*: Several decades ago, scientists habitually classified almost every new hominid (man-like) find into a separate species. These fossil creatures were thus named "Peking ape-man", "Java ape-man", "Neanderthal man," and so forth. Drawings of the day used to show an upward development: some primitive ape leading to the ape-man, who in turn led to Neanderthal, who then led to Cro-Magnon (identical to "modern" man in nearly every respect).

Within the last 25 years, these have all been reclassified. All the "ape-man" types (from 100,000 to 500,000 years ago and more) now belong to one species, *Homo erectus*, the "upright man." Neanderthal, we now believe, was a racial type of modern man, *Homo sapiens*. But this distinction needs some clarification. In what sense were these two forms of man different? Were they really separate and distinct species?

The true test for species difference is genetic isolability--that is, whether mating of two individuals will produce sterile offspring or not. But obviously we have no way to determine this among creatures long dead.

It is important to realize that, when scientists classify ancient fossils into distinct species, they do so exclusively on the basis of anatomical structure. If a given specimen has bone configurations within the known range of a given species, then it is called by that species' name. If, however, some significant features lie outside that range, then it probably belongs to a different species and is thus classified differently. *Homo erectus* had several anatomical features which differ from those of modern man. He had, for example, a prominent brow ridge over his eyes, a smaller stature, and a smaller average brain size.

The key point here is that both were forms of man, the genus *Homo*, with all that this implies. The anatomical variation was possibly, even probably, the only significant difference. We know that *erectus*, even from remotest antiquity, made several types of tools and used fire. Both of these activities show intelligent manipulation of nature. In other words, he, like the *sapiens* form, could think.*