From Socialist Review, No. 173, March 1994.
Copyright © Socialist Review.
Copied with thanks from the Socialist Review Archive.
Marked up by Einde O’Callaghan for ETOL.
Shadows of Forgotten Ancestors
Carl Sagan and Ann Druyan
I was rather apprehensive on picking up this book. Claiming to be a Roots for the human species, it tries to locate the source of society’s problems in our evolutionary past.
But I found Shadows of Forgotten Ancestors a fascinating, if flawed, read. Although it does not succeed in its aims, failing to understand the features that distinguish humans from other animals, it offers an excellent account of our biological origins.
Two major themes of natural history emerge. The first is the importance of chance. For instance, the earth was once much larger than it is today. A chance collision with another world split it in two, creating the moon in the process. Had the collision been more severe, it is probable that there would be no earth today.
Another planetary collision was probably responsible for the demise of the dinosaurs, which in turn created a space for the rise of our mammalian ancestors.
The second theme is that, whilst evolution is generally characterised by slow, gradual change, it is also true that the most far reaching changes have occurred through revolutionary transitions. Such transitions may be caused by unforeseen catastrophes such as those already described, but more interesting is the fact that they are often the result of contradictions that emerge in previous conditions and which overturn those conditions in the process.
The earth’s history is full of such examples. Environmental crisis is not new and is not confined to human activities. What is different is that we now have the power to do something about it.
Which brings me to the second part of the book. What makes us different from other animals, in particular from our closest relative, the apes? There is a problem here. On the one hand there is apparently very little biological difference between humans and apes. We share an incredible 99.6 percent of our active genes with chimpanzees.
On the other hand there are the obvious differences between humans and apes – our language, society and culture. Is all this skin deep? Clearly the authors think so.
I felt that this book misses the one crucial difference between humans and apes – our ability to consciously change the environment – because it fails to understand the nature of human consciousness.
Consciousness arose in human evolution when our ancestors first began to use tools. Tool use must have evolved as a social activity because at some point early on it became linked with the growth of language. We know this because one of the distinguishing features of human brains is the way that the centres controlling language and the hands are connected. Social interaction coupled with tool use stimulated the evolution of the brain.
Human evolution did not require a great deal of genetic change, involving as it did a restructuring rather than a rebuilding process. However, the differences that do exist are crucial. Although apes can use tools, it seems that they will only use objects that come immediately to hand in a particular situation.
This book views us merely as ‘civilised apes’. It draws the pessimistic conclusion that we are prisoners of our animal instincts. Worse still, we have lost the mechanisms that other apes have evolved to preserve social harmony. The authors completely miss the point that we are social beings and as such it is society rather than biology which is the dominant factor in determining even our most basic functions.
Last updated: 8 March 2017