Life's Grandeur: The Spread of Excellence from Plato to Darwin
By Stephen Jay Gould
Jonathon Cape, 1996. 244 pp., $39.95 (hb)
Review by Phil Shannon
http://www.greenleft.org.au/node/15538
It pays to know your maths. In 1982, Stephen Jay Gould was diagnosed as suffering from abdominal mesothelioma. The median life expectancy, he learned, was eight months.
This grim statistic, which could psychologically hasten the death of the sufferer, did not phase Gould. Whilst half the sufferers do die within eight months, and half live longer, the mean, or average, survival time is more than eight months. The distribution, or bell curve, of survival is right-skewed; some fortunate individuals, like Gould, are perched on the extreme tip of the right tail of the distribution.
Gould's latest book is about skewed distributions, the full spread of variation and their implications for the concept of progress in the history of life on our planet.
The common view of Darwin's theory of evolution, that evolution is a positive progression from amoeba to dinosaur to us, is wrong, says Gould. Life is not the story of an inevitable rise from the Age of Invertebrates to the Age of Reptiles to the Age of Mammals to the Age of Man. Most individual organisms are still single-celled bacteria, and most multi-cellular organisms are beetles.
Since life began on earth 3.5 billion years ago, it has always been the Age of Bacteria. Occasionally, some twigs on some branches of the evolutionary bush wander away from the bunched-up left tail of minimal complexity into the right tail of brainier, more complex organisms. This is not "progress", but rather "random motion away from simple beginnings".
Some of these elite species do incredible things with their big brains, language and social organisation, but they are not the tail that wags the dog. Bacteria still rule.
We should not, says Gould, focus on the right tail of the skewed distribution of complexity but rather the whole range. One third of his book is given over to a discussion of why 0.400 batting (four safe hits for every 10 times at bat, a measure of batting prowess) in professional baseball has disappeared since 1941.
To focus on this one part of the distribution of measures of baseball performance is misleading, says Gould. The focus should be on the whole spread of variation, which would show the decline of 0.400 batting as a shrinking right tail, contracting closer to a stable mean because the best batters now meet more skilled pitching and fielding, which does not permit extremes of batting accomplishment.
Gould also illustrates the problem of extremes versus variance in the case of the modern horse. Often thought to demonstrate the principle of progress in evolution from small, grazing, running mammals to today's thoroughbreds hurtling down the straight at Flemington, the horse represents evolutionary failure, says Gould.
Dobbin is the sole surviving remnant of a formerly bushy and successful group of creatures that has fallen on hard times. Diversification, rather than narrowing directional change is the criterion of success.
In evolution, nothing is inevitable, everything is contingent — "if one small and odd lineage of fishes had not evolved fins capable of bearing weight on land ... terrestrial vertebrates would not have arisen and if a large extra-terrestrial object .... had not triggered the extinction of dinosaurs 65 million years ago, mammals would still be small creatures confined to the nooks and crannies of a dinosaurs' world".
We must repent of our species pride, for we are but "accidents of an unpredictable process with no drive to complexity".
Darwin himself "denied progress as a predictable outcome of evolution". Yet, Darwin, having eliminated divine creation from the scheme of human development, fudged the issue of natural progress in his public works.
Gould has always been conscious of the social and political context of science. He argues that whilst Darwin was intellectually radical, he was socially conservative, a wealthy squire who owed his comfort to the ideology of "progress", which was used to justify the wealth and power of his class in its cultural, industrial and imperialist expansion. So Darwin smuggled progress back into his theory, against all his empirical evidence.
Why does any of this matter? Gould argues that the continued existence of life on earth, including our future, depends on preserving biodiversity, and this "requires a reorientation of human attitudes to other species" — from an "attitude of little care and maximal exploitation to interest, love and respect".
We must see that our "transient domination" of the biosphere through technology does not imply "intrinsic superiority or guarantee prospects for extended survival".
Major scientific revolutions, from heliocentric astronomy to Darwinian evolution (which Gould aims to complete through excising the concept of Darwinian "progress"), are essential for the "dethronement of human arrogance". We ignore bacteria and bugs at our peril, whilst they will be unmoved if we disappear from the evolutionary tapestry through polluting our nest or through military conflagration.
Gould stresses that whilst we may be but an accident of life, we are a "glorious accident". Cultural evolution is different from natural evolution — through education, consciousness and social effort, human social change can be "explosively rapid and directional". Gould has a beef with the "inevitable historical progress" of vulgar "Marxism", but his message is not at odds with a Marxism which sees human history as something shaped by conscious human intervention.
If all of humanity and all of our biological cohabitants on this wonderful planet do discover harmony, then the sparkling intellect, artistic fluency and human compassion of Stephen Jay Gould on our little right tail of "life's grandeur" will have played its part.