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Stephen Jay Gould
Stephen Jay Gould, who recently died of cancer, was an outstanding contributor to evolutionary theory. But more than this, he had the rare ability to popularise a wide range of scientific thought. PETE MASON writes.
GOULD’S SUBJECTS WERE diverse: evolutionary theory, geology, biological determinism and the history of science. He campaigned against creationism and racism in scientific research. Describing himself as a ‘leftist’, he "could be seen at demonstrations and on picket lines, especially during the 1960s and 70s". (Stephen Rose, Guardian, 22 May) In the same newspaper, Steve Jones compared him to Darwin, "a working scientist", passing many uncomfortable summers "scraping away at lumps of rock". Gould’s many books, and particularly his collections of essays, hit the best-sellers lists, earning him book-jacket acclamations, such as ‘The greatest living scientist – The Sunday Times’. The US Congress named him one of America’s ‘living legends’.
Yet to many scientists Gould was a misguided heretic. Occasionally demonised as a Marxist by his opponents, Gould’s theory of ‘Punctuated Equilibrium’ (written with Niles Eldredge) moved from a ‘Marxist’ curiosity to a mainstream contender for a more accurate understanding of the development of species in the thirty years since its publication in 1972.
Gould appears to have consciously attempted to apply a broadly-Marxist method of analysis to evolution (and the many other subjects he specialised in). And that’s enough to put most establishment scholars into a state of fear and loathing.
Gould’s essays, particularly his earlier ones, should be recommended reading, lessons not just in evolution in nature, but in dialectical thought. Gould wrote: "Dialectical thinking should be taken more seriously by Western scholars, not discarded because some nations of the second world [the so-called Communist East] have constructed a cardboard version as an official doctrine". (An Urchin in the Storm, 1988, p153) From a left-wing background (his father was a political activist), Gould concludes this essay with Karl Marx’s famous remark: ‘Philosophers thus far have only interpreted the world in various ways: the point, however, is to change it’.
In An Urchin in the Storm, a collection of book reviews published in the New York Review of Books, Gould writes: "Hegelians and Marxists have long advocated the ‘transformation of quantity into quality’ as a basic statement about the nature of change. Graded inputs need not simply yield graded outputs. Instead, systems often resist change and absorb stresses to a breaking point, beyond which an additional small input may trigger a profound change of state… Our metaphor about straws and camels’ backs reflects an implicit understanding that not all change is continuous". (p209)
Gould applied this particular aspect of dialectical thinking to the evolution of species in the theory of Punctuated Equilibrium. He points out that the great evolutionist Ernst Mayr popularised the generally held ‘allopatric theory’ of speciation, in which small populations of a species become isolated and undergo very rapid evolution into a new species. Gould points out that all he has done is recognise that "If evolution almost always occurs by rapid speciation in small, peripheral isolates – rather than by slow change in large central populations – then… during [a large central population’s] recorded history in the fossil record, we should expect no major change". (Ever Since Darwin, 1978)
Progress & complexity
GOULD ARGUED AGAINST those who suggest that evolutionary development is driven by a purpose – that there is a guiding hand, as it were, in evolutionary development – an inevitable progress up a ‘ladder’ from lower to higher life forms and, finally, to homo sapiens. Natural selection itself does not imply a progression from lower to higher life forms, argues Gould: "Life is a ramifying bush with millions of branches, not a ladder. Darwinism is a theory of local adaptation to changing environments, not a tale of inevitable progress. ‘After long reflection’, Darwin wrote, ‘I cannot avoid the conviction that no innate tendency to progressive development exists’." (An Urchin in the Storm, p211)
One of Gould’s recurrent themes was life’s ‘contingency’. He does not deny that natural selection leads to a greater complexity of life forms. But the developing complexity of life, Gould maintains, is only a by-product ‘incidental’ to evolution and not necessary or inevitable. And complex creatures represent only a tiny proportion of the whole.
Moreover, evolution on Earth has been punctuated by five mass extinction events. What role do these events play in shaping evolutionary development? In Wonderful Life, Gould studies fossils in the Burgess Shale in the western Canadian Rockies from the Cambrian geological period, half a billion years ago. These are the remains of the first explosive development of multi-cellular life. This ‘Cambrian explosion’ is an example of the rapid development of life forms. But it was followed by the mass extinction of all but a few of the many weird and wonderful designs.
Gould explains that just a few body forms survived the aftermath of the Cambrian explosion. Subsequent evolution of these forms remained confined to the basic architectural design of the original. Gould argues that if backboned creatures (chordates) had not survived this period, vertebrates, such as fish and mammals, would never have subsequently evolved.
In Wonderful Life Gould shows how Conway Morris and Harry Wittington, who studied the Burgess Shale, eventually drew the conclusion that chance alone governed which of the creatures from the Cambrian explosion survived the subsequent extinction. Morris, in a major article in Science magazine, concludes that the "macro evolutionary patterns that set the seal on Phanerozoic life are contingent on random extinction". (October 1989) If you were to replay the tape, says Gould in Wonderful Life, and a mass extinction event expunges the Lungfish group of fish species that crawled onto land out of the sea, "our lands become the unchallenged domain of insects and flowers". (p318)
But the anthropologist Richard Leakey, like many evolutionary biologists, questions Gould’s conclusions. Perhaps some creatures survived mass extinction events because they were the fittest, while others survived due to chance. "I believe that Gould has been correct to raise our consciousness to the role of contingency in life’s flow, although I suspect he pushes the argument too far". (The Sixth Extinction, p86)
Does complexity not sometimes confer an advantage of survival even in mass extinction events? If, for instance, the ancestors of the mammals survived the extinction event that ended the rule of the dinosaurs because they made their nests in burrows and were able to hibernate through the devastation of the asteroid impact, would not this be an example of a more complex set of behaviours leading to survival? On the other hand, maybe the earliest known ancestor of the vertebrates, Pikaia gracilens, a two-inch ribbon-like chordate, survived because its backbone was a simpler solution to body design. Furthermore, what is the role of convergent evolution? Examples of convergent evolution can be found in the many mammals that returned to the sea and evolved outwardly to look similar to big fish.
But if this can and did happen, why should Gould appear to rule out some other sea creature evolving to breathe air and walk on land if the lungfish didn’t make it? To be sure, close inspection would then reveal a radically different physiognomy, but convergent evolution and architectural constraints (another theme of Gould’s) would limit the forms of those land creatures with larger body sizes.
One of Gould’s most famous collections is The Panda’s Thumb, in which he describes the evolution of the Panda’s ‘thumb’, a muscled and flexible digit which evolved from a bony part of its forepaw and is used to grasp the bamboo the Panda subsists on. Gould concludes with Charles Darwin’s remark that nature displays a "prodigality of resources for gaining the very same end" with limited raw material (in this instance Darwin is referring to orchids). Surely this stands in contradiction to Gould’s claims that if the lungfish group of species had not survived a mass extinction event, land would be the ‘unchallenged domain of insects and flowers’. Would not nature have risen to that challenge?
From Darwin to Dawkins
AMONGST MANY OTHER themes in Gould’s writings (which are not possible to touch on here) his mastery of the history of science is a joy to read. In depicting the development of Darwin’s ideas, Gould does not hold back from demonstrating in fine detail the conflicts within his writings:
"Marx and Engels were quick to recognise what Darwin had accomplished and to exploit its radical content", remarks Gould (Ever Since Darwin, 1978) adding that "Darwin was, indeed, a gentle revolutionary". But Gould also distils out the more conservative elements in Darwin’s work and presents them for criticism. Darwin was an "intellectual radical" but a "cultural conservative".
The result was, in turn, a rejection and then an adoption of the bourgeois ideology (expostulated by the philosopher Edmund Burke 50 years earlier) of a slow ‘organic’ progress, consciously adopted by the British ruling class after the French Revolution of 1789 executed a very rapid, revolutionary type of change in a thorough exposition of the dialectic.
Of course, speciation may still take hundreds, thousands, and indeed hundreds of thousands of years. But this is still "a geological microsecond" in the average five million year lifespan of a single species. By comparison, Gould’s would-be nemesis, Richard Dawkins, author of The Selfish Gene, writes that evolutionary problems can be solved "if only a slow, gradual step-by-step pathway can be found". (Climbing Mount Improbable, 1996)
Dawkins’ Climbing Mount Improbable is clearly meant as a refutation of Gould and contains a strongly worded denunciation of him. But it misrepresents the full lifespan of a species, let alone the large-scale evolution over the history of the planet. Gould, for his part, takes issue with the reductionism of Dawkins: the fatal flaw of the selfish gene theory is that, "Selection simply cannot see genes and pick them directly. It must use bodies as an intermediary. A gene is a bit of DNA hidden within a cell. Selection views bodies. It favours some bodies because they are stronger, better insulated, earlier in their sexual maturation, fiercer in combat, or more beautiful to behold… There is no gene ‘for’ such unambiguous bits of morphology… bodies cannot be atomised into parts, each constructed by an individual gene". (The Panda’s Thumb, p76)
Gould protests that Dawkins’s theory arises from "some bad habits of Western scientific thought… the idea that wholes should be understood by decomposition into ‘basic’ units; that properties of microscopic units can generate and explain the behaviour of macroscopic results".
Gould’s exploration of the complexity of evolutionary development (and of many other natural processes) is far richer than Dawkins. Indeed, the lack of a true dialectical, many-sided approach to development, whether in the natural world or in human society, hinders the development of our understanding of processes throughout nature and human society, as Gould demonstrates with great gusto.
By a strange coincidence, a few days before Gould died the BBC showed an episode of The Simpsons in which Gould was the special guest, doing a voice-over of a remarkable likeness of himself. Gould would have been very happy with this as his obituary. His references to popular culture (particularly baseball) are a defining mark of his essays, which appeared every month in Natural History magazine for nearly thirty years.
In The Simpsons episode, a giant supermarket chain plants a fake ‘angel’ fossil, as a marketing ploy. Capitalism is shown using creationism and exploiting people’s religious beliefs to make a quick buck, just as the Republican religious right use campaigns around creationism to bolster support for their anti-working class policies. Gould continually campaigned against creationism, but never attempted to compromise on a complex truth when presenting his arguments to the public.
Stephen Jay Gould died on 20 May 2002.
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