How do the ideas of Engels, The Part Played by Labour in the Transition of Ape to Man, stand in the light of the most recent theories of evolution? One of the foremost modern palaeontologists is Stephen J. Gould. In his book Ever Since Darwin, he gives the following appraisal of Engels’ essay:

Indeed, the nineteenth century produced a brilliant exposé from a source that will no doubt surprise most readers – Friedrich Engels. (A bit of reflection should diminish surprise. Engels had a keen interest in the natural sciences and sought to base his general philosophy of dialectical materialism upon a ‘positive’ foundation. He did not live to complete his ‘dialectics of nature’, but he included long commentaries on science in such treatises as the Anti-Dühring.) In 1876, Engels wrote an essay entitled, The Part Played by Labour in the Transition from Ape to Man. It was published posthumously in 1896 and, unfortunately, had no visible impact upon Western science.

Engels considers three essential features of human evolution: speech, a large brain, and upright posture. He argues that the first step must have been a descent from the trees with subsequent evolution to upright posture by our ground-dwelling ancestors. ‘These apes when moving on level ground began to drop the habit of using their hands and to adopt a more and more erect gait. This was the decisive step in the transition from ape to man.’ Upright posture freed the hand for using tools (labour, in Engels’s terminology); increased intelligence and speech came later.[44]

Despite everything, idealist theories of human evolution still conduct a stubborn rearguard action against materialism, as we see from the following extract from a book published as recently as 1995:

“The force that is likely to have driven our evolution [is]…the process of cultural evolution. As our cultures evolved in complexity, so did our brains, which then drove our bodies towards greater responsiveness and our cultures towards still greater complexity in a feedback loop. Big and clever brains led to more complex cultures and bodies suited to take advantage of them, which in turn led to yet bigger and cleverer brains.” (Wills)[45]

Idealists have repeatedly attempted to assert that man is distinguished from the “lower” animals by his superior intelligence. Evidently, early man, for some unexplained reason, first “became intelligent”, then began to speak, use tools, paint pictures and so on. If this were true, one would expect it to be reflected in a significant increase in brain size very early on. However, the fossil record proves that this is not the case.

In the course of the last three decades, there have been a series of tremendous advances in the science of palaeontology, new and exciting fossil discoveries and a new way of interpreting them. According to one recent theory, the first bipedal apes evolved as far back as seven million years ago. Subsequently, in a process known to biologists as “adaptive radiation”, there was a proliferation of bipedal species (that is, species which walked on two legs), with the evolution of many different species of bipedal apes, each adapted to different environmental conditions. About 2-3 million years ago, one of these species developed a significantly larger brain – Homo erectus. These were the first hominids to use fire; to use hunting as a significant source of food; to run in the same way as modern humans and to make tools according to a definite preconceived mental plan. Thus, the increase in brain size coincides with the first appearance of tool-making activity, approximately 2.5 million years ago. Thus, for 5 million years, there was no significant expansion of brain size, and then a sudden leap, which is clearly identified with the production of tools.

Molecular biology indicates that the earliest hominid species appeared about five million years ago, in the form of a bipedal ape with long arms and curved fingers. The proto-human Australopithecus had a small brain – only 400 cubic centimetres. The qualitative leap took place with Homo habilis, who had a brain size of more than 600 cubic centimetres – i.e., an astonishing increase of 50 per cent. The next big advance was with Homo erectus, with a brain size of between 850 and 1100 cubic centimetres.

Not until the emergence of Homo sapiens sapiens about 100,000 years ago does the size of the brain reach modern levels – 1350 ccs. Thus, the earliest hominids did not possess large brains. Human evolution was not powered by the brain. On the contrary, the enlarged brain was the product of human evolution, especially the making of tools. The qualitative leap in brain size takes place with Homo habilis (“handyman”) and is clearly identified with the production of stone tools. In fact a new qualitative leap takes place in the transition from Homo erectus to Homo sapiens. John McCrone writes:

The human mind appeared on Earth with astonishing suddenness. Just 70,000 years – the merest eye-blink of geological time – covers our ancestors’ transition from smart ape to self-conscious Homo sapiens.

On the far side of the evolutionary divide stands Homo erectus, a clever beast with a brain almost as big as a modern human’s, a simple tool culture and a mastery of fire – yet mentally still somehow lacking. On our own side stands Homo sapiens with the rituals and symbolic art – the cave paintings, beads and bracelets, decorative lamps and burial graves – that mark the arrival of a self-aware mind. Something sudden and dramatic must have happened, and it is this event that could be the starting point for human consciousness.[46]

  1. Gould, S. Ever Since Darwin, pp. 210-1.

  2. Wills, C. The Runaway Brain, The Evolution of Human Uniqueness, p. xxii.

  3. New Scientist, 29 January 1994, p. 28.