I found the discovery of the fossils of Australopithecus sediba (Au. sediba) fascinating. On secondsightblog.net I have noted some links for those who want to study these South African finds more closely. Here, I will confine myself to major points of interest.
The fossils of several remains are dated to about two million years ago, that is, just earlier than our oldest fossils of homo erectus, whom scientists believe to be our direct ancestor. Many will know of the Australopithecus family through “Lucy” (who predates Au. sediba by about a million years).
The fossils show some interesting details. While the hand is suitable for climbing, the fingers and thumb make it also suitable for precise grasping; it may well have been a maker of tools. Its ankle is similar to the human ankle, but the shin bones and feet have some chimpanzee characteristics. The best guess is that it could walk bipedally but was also accustomed to living in trees.
Its brain was small – about the size of a grapefruit – but study of the brain shape, from casts taken on the inside of the skull, show changes in the frontal lobe which suggest brain development in a human direction. But, interestingly, the female pelvis is wider than expected. This suggests that the wide human pelvis was not simply a development to allow for the cranial size of modern humans.
Is Au. sediba our direct ancestor? At that time, and before that time, it would seem that a number of lines pointing in the human direction developed and were extinguished for one reason or another. But one of these must have been sufficiently successful to act as the transitional link to Homo erectus and eventually Homo sapiens: you and me. Au. sediba is at least a likely candidate, in that it shows both chimpanzee and human characteristics. Further studies will help us here. Sediba is a word from the Sotho language; it means wellspring.
Pius XII taught in Humani Generis that it was legitimate to hold that man’s body was the result of evolution but that the soul was a direct creation of God. The view that there may be humans not descended from Adam, or that Adam represents a certain number of first parents, is held to be inconsistent with revelation and tradition.
Neither of these points need cause us much difficulty. Au. sediba, or some similar creature, must have been in the evolutionary line which leads to the physical aspects of Homo sapiens. But the soul requires different consideration.
A good marker for the existence of a soul is moral sense – that is, the capacity to recognise good and evil and to choose freely between them. In infancy and, in some circumstances in later life, moral sense cannot be exercised. But at all times the soul is the animating principle of the whole body, and the human soul has the potential of moral sense as a profound element.
While our moral sense can be developed and extended, its potential in our nature either exists or it doesn’t. Our nature cannot nearly have moral sense. It follows that it must be a direct, and not evolved, creation.
Our common descent from one man (Adam means “man” in Hebrew) does not seem to be an issue in principle from a scientific point of view. Researchers posit a single female and a single male ancestor from whom we are all descended. But these are not contemporary with each other and are thought to be our most recent common ancestors rather than the first of our common ancestors.
We do not know whether a moral sense was first present in sedibus or in habilis or in erectus or in sapiens. I would put sapiens as prime contender, but who knows? A recent report on a skull found in Iwo Eleru, Nigeria suggests a specimen midway between archaic man and modern man. Its characteristics accord with skulls dated over 100,000 years ago, but its actual age is about 13,000 years. A legitimate inference is that modern man and archaic man in western Africa continued to interbreed until relatively recently. It has been known that, out of Africa, sapiens has interbred with Neanderthals and Denisovans. Most of us in the West will be up to three per cent Neanderthal. It is even possible that an ensouled sapiens bred directly with a similar, but unsouled, species – and so produced ensouled offspring. We can but speculate.
Pius XII’s concern is to link the whole race to Adam, and therefore inheritors of Original Sin – committed by the first Adam, redeemed by the second. And certainly we are aware that our common inheritance is a sorry disintegration between our animal and our spiritual natures. Paul’s experience, “For I do not do the good I want, but the evil I do not want is what I do”, encapsulates our disharmony between body and soul, which Adam actualised through his first sin. Resurrection will not be the perfecting of the soul but the integration of the whole human being into God’s likeness. That is what redemption means. It is not by chance that the only human beings who have resurrected so far are the two who were conceived without the disharmony which we call Original Sin.
I realise that I am touching on some difficult theological concepts, but one of the great joys of writing without authority is that anyone who wishes can, and should, either disagree with me or refine what I say. The place to do that is Secondsightblog.net, where you will meet a number of thoughtful people who like to discuss such matters seriously.