Begegnungen
Schriftenreihe des Europa Institutes Budapest, Band 22:71–83.
JOSEPH HELD
Science Wars*
I. Introduction
In our times, when the information revolution has achieved global reach, when the internet is now frequently being consulted even in some of the remotest villages of Asia, Africa and Australia, “science” has become a supreme engine of change. Its definition is, however, problematical. There are so many activities labelled “science” that they can hardly be considered to belong to the same category. The term “science” had become similar to other over-generalized concepts, such as “revolution,” “space,” and so on. In Western usage – in Great Britain, the United States, and in most West European countries, – science is usually considered to consist of the so-called “hard- or natural sciences.” These include organic and inorganic chemistry, biology, physics, medical sciences, mathematics, geometry, astronomy, archaeology, palaeontology and environmental science. (Some of them are combined into biochemistry, paleo-anthropology etc.) The other branches of scholarship are subsumed under the rubrics of the humanities – history, language-studies, literature – while the so-called social sciences include sociology, psychology, folklore and political science.
One of the reasons for these distinctions is that the various fields of scholarship are being ordered into “ranks,” according to their alleged importance from the point of view of their utilitarian “usefulness” for society. In an age when technology and the practical application of knowledge are being considered to be the foundation of societal existence, – as our age surely is – this should not surprise anyone.
Science as a concept and practice – whatever its definition – has been the engine that drove Western Civilization toward ever greater heights. It has been the distinguishing element that propelled European peoples to extend their influence over the entire globe during the past five centuries.1 Its technological application resulted in the modernization of life (whatever this means) in the last two centuries. On the other hand, the conflicts that have emerged between science and religion, and later between various social ideologies and science, originated in the very first society in ancient Greece, where the foundations of scientific inquiry were first established. One is justified in saying that the first open conflict between rational thinking and thinking based on feeling and emotions, came about with the appearance of Socrates and his disciple, Plato. Most educated people are familiar with that story and its sorry ending. But the real conflict emerged with the triumph of Christianity; the sermon of Pope Gregory the Great2 highlighted the fundamental conflict between thinking by using the rules of logic, laid down by the classical Greek philosophers, and the newly triumphant Christian religion’s emphasis on faith as the sole arbiter of “truth.” Since that time, this duality has been running through Western history like a red thread; its dividing lines separated the so-called Jesuit saint, Cardinal Bellarmini and Galileo Galilei; it characterized the deadly attempt to control science and the emerging scientific approach applied to the discovery of the “secrets” of nature and the cosmos by the ignorant and malicious priests of the inquisition. The conflict is really unsolvable, because religion is allegedly based on revelation by God, and science is the product of the ingenuity of the human mind, of reason.3
With the coming of the Enlightenment in Western Europe in the 18th century it seemed that the control of intellectual life by religious authorities had come to an end. The two fields of human endeavour, scientific research and knowledge based on faith, seemingly had been effectively separated. Francois Marie Aruet (Voltaire) could openly denounce religion as a concept that was allegedly an obstacle to the spread of knowledge. He propagated a belief in the “religion of nature,” called “deism,” which was, according to him, necessary for the simple people in order to keep their passions in check. Atheism had also become one of the (permissible) forms of thought, although its influence had never become overwhelming in the Western world.
The Enlightenment has seemed to open the floodgates of science and eliminate the break on its development by religious authorities. But the war had not yet ended. In fact, it was renewed by the discoveries of Charles Robert Darwin (1809-1892). Anglican Bishop Samuel Wilberforce (1805-1873) and Thomas Henry Huxley’s (1825-1895) famous debate about Darwinian findings about evolution is well known, and there is no need to rehash the arguments in this essay. What concerns us here are the struggles that have developed in the course of the late 19th and 20th centuries between individual scientists arguing over the “right” science on the one hand, and the pseudo-sciences that have been spread by extreme religious sects, pseudo-scientists and the modern sensation-seeking communications-media. Even in this effort we must be selective.
II. Catastrophism vs. Continuous Evolution; When Life Nearly died4
Scientific controversies, as I indicated before, are not new and are not surprising. Yet, in almost every case concerning the “hard” sciences, when a new concept or theory is presented, – usually for reasons intrinsic to the subject in question – further research usually sets the record straight. It usually takes time for the process to work, but accumulating evidence for or against the theory in question is decisive.5 This was the case with two conflicting paleo-biological concepts examining the two greatest mass extinctions of life in 251 million and 65 million years ago. The advocates of catastrophic causes and the supporters of a gradual process leading to mass extinctions struggled with each other for nearly 150 years. Eventually, however, new evidence decided the issue at the beginning of the 21st century.
For almost two millennia, geological time was correlated with the Christian Bible. Fenciful “studies” asserted that the age of the earth was about 6,000 years only, and some religiously inclined geologists agreed, because “God (Scripture) said so.” Then in the course of the 18th century, strange fossils came to light that seemed to point to much older time for the existence of life, and therefore, of the earth. The fossils showed that animals had existed in the past that did not resemble any living creatures in contemporary times. This, in turn, seemed to point to a much older earth than the Bible suggested, and also to the fact that living things did die out. Was this also God’s plan?
With the passage of time – and more research – it was becoming more and more evident that there had been several mass extinctions in geological time, and further research revealed by the early 19th century, that at least two of these mass extinctions almost ended life on earth. However, the disputes continued over whether the extinctions were the result of great catastrophes or were they simply the manifestations of a gradual process. By the early 19th century, paleo-geologists agreed that extinctions were “natural,” and that the fossil records indicated that both animal and plant species, unable to adapt to environmental changes, exited from the living and their empty niches were soon filled by others better suited to “nature.” The first ideas of evolutionary processes appeared and gradually became part of the accepted history of the earth. Yet the issue of gradual versus catastrophic extinctions continued unresolved and for more than a century and a half the gradualists dominated the dispute.
The foundations of gradualism were laid down by two Scottish geologists, Roderick Murchison (1792-1871) and Charles Lyell6 (1797-1878). Murchison was a practical-minded geologist. He was uncomfortable with controversies and was the happiest when out in the field, doing his work with rocks. He was also a cautious man, perhaps even timid, avoiding disputes as much as he could, sometimes even rejecting the evidence of his own eyes.
Not so Charles Lyell. In the early 1830’s he published a three-volume textbook on geology7 which became the textbook of the subject, and which is being considered even today to be the foundation of geology as a science. Yet the work was flowed. Lyell suggested that plants and animals live and die out in response to environmental changes. He stated that all geological phenomena could be explained by comparison to modern processes; this was the concept of “uniformitarianism,” and it suggested that geologists must examine changes in the past by comparing them to contemporary phenomena. Lyell denied that there had been sudden mass extinctions of life in the geological past and no catastrophic events interfered with life on earth. He also asserted that major groups of living organisms could never disappear entirely; instead, they were continuously recycled.
Lyell was contradicted by some other geologists, foremost among them the Frenchman Georges Cuvier. He simply rejected Lyell’s arguments. After all, notions of mass extinctions were not new, they circulated ever since the 17th century, when the origin of earth had been hotly debated. Cuvier began studying fossil skeletons in the Paris basin in 1800, and found complete specimens of small horse-like and dog-like skeletons. He suspected that these were remnants of long extinct animals. He proved that processes that were operative in their time, were no longer in effect. In a great book8 Cuvier had shown that the physical processes at work in his day were quite different than those in the past, and the latter included catastrophes. He stated that
…this development was sudden, not gradual, and what is clearly demonstrable for the last catastrophe is not less true for those that preceded it…Life in those times was often disturbed by these frightful events. Numberless living things were victims of such catastrophes; in some, living inhabitants of dry lands were engulfed in deluges, others living in the sea, were left stranded when the ocean floor was suddenly raised up again; and whole races were destroyed forever, leaving only a few relics which the naturalists can scarcely recognize.9
Cuvier saw that different layers of sediment are often separated by discontinuities. The problem was that his “catastrophes” could be connected to Noah’s flood in the Bible! Not surprisingly, Cuvier’s ideas were used to support the Biblical story, as one of the great catastrophes that affected earth, even if he himself would have vehemently denied the possibility. His theory was influential in continental Europe, but in England Lyell’s ideas have prevailed and eventually overcame Cuvier’s influence.
Although Cuvier himself also argued that geologists must base everything on modern processes and the already discovered laws of nature, Lyell succeeded in libelling him as nothing more than a speculator, the enemy of true science. Cuvier stressed his opinion that there were great upheavals in the past and Lyell charged that this was nothing but speculation without proof. But he himself lacked real evidence for his beliefs, as Cuvier had also been in the same position. In the end, both of them missed the point.
How could Lyell’s theory survive without serious questioning for a century and a half? What was its appeal that enabled Lyell and his supporters to call all other considerations “wild speculation?”
One of the answers may be that Lyell’s theory appealed to conservative-minded scientists who were gratified to learn that nothing has ever changed in earth’s fundamental conditions. In a turbulent age, when intellectual and political revolutions swept over the European continent, followed by Napoleon’s “new order” and its eventual collapse, it was gratifying to learn that nothing ever drastically changes in the world and that stability is always maintained after changes that come and go in a cyclical sequence. According to Lyell,
…volcanoes erupt, glaciers advance and withdraw, sea levels go up and down, but everything is in equilibrium. The earth is a closed system with certain fixed laws and there can be no progress, or direction of change…
Geologists, however, did not stop research because of Lyell’s strictures. They eventually found that there was a certain order to fossils in the rocks; simple marine organisms came first, then fishes, followed by animals on land, then reptiles and finally mammals. Lyell rejected such an idea of progression. He expected the eventual discovery of mammals in the earliest deposits and believed that dinosaurs might return at some time in the future.
Strangely enough, although many geologists disagreed with Lyell, they were unwilling to come out too strongly against him for fear of being labelled a “catastrophist,” and exposed to ridicule.
Lyell was eventually criticized and, late in the 20th century, was proven utterly wrong. However, it took Darwin to shake his reputation in the 1860’s. Yet, his ideas were still not rejected outright, at least not until the 1980’s, and they continued to dominate thinking in geology.
*
In the meantime, the stratification of earth’s history continued steadily. It became evident that geological time was measurable not in centuries, or even in millennia, but in hundreds of millions, or even many billions of years. The names given to each recognizable period distinguished among four major periods (pre-Cambrian, Palaeozoic, Mesozoic, and Cainozoic ages), extending over about 600 million years, and 11 shorter periods within these ages defined by sediments and rocks and other materials. (Vendian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous and Tertiary.)
There were geologists even in Lyell’s time, including Murchison, who had already possessed evidence to destroy Lyell’s gradualist theories. In a letter written in 1851, Murchison stated: “…Operations of great violence, not of Lyell’s quietude, have been repeated.”10 Geologists were eventually convinced that fossils found in earth’s various strata were different in different ages, and that there were major gaps at which fauna and flora had changed in geologically short intervals of time. Yet, this argument had carried no weight in the Lyellian system of cyclical changes.
The story of how these long accepted views were demolished and a modern contemporary theory of earth’s evolution and “catastrophism” triumphed shows a painstakingly slow, convoluted process, reaching into the 1980’s and beyond.
*
Geologists and palaeontologists gradually have come to the realization that gaps in the fossil record were not simply the result of lack of research, but that they were showing several mass extinctions. Of these five were identified, and of them, two were of major proportions, one occurring 251 million and the other 65 million years ago. They were of such magnitude that they could not be explained by Lyell’s gradualism.11 Darwin stated that species had died out occasionally as the result of environmental competition, because the principle of the “survival of the fittest” operated harshly. However, it gradually became clear that the largest extinctions, the one 251 million years ago at the end of the Permian period, and the other 65 million years ago at the border between the Cretaceous and Tertiary ages were of such magnitude that only catastrophic events could bring them about. The latter aroused special attention because it corresponded to the extinction of the dinosaurs, and public imagination was easily excited by images of giant reptiles and sea creatures.
In the 1970’s mass media took over from the scientists. Books, films and TV shows flooded the airwaves, and children learned the names of long extinct giants, strange creatures and fishes. This, of course, provided great opportunities for dilettantes and dilettantism, which did not really advance scientific research.
*
By the 1950’s however, American and British scientists were on their way to put together a synthesis further developing Darwin’s evolutionary discoveries with new findings in genetics, geology and palaeontology, and were re-examining the evolution of earth’s environment.
At this point the German Otto H. Schindewolf12 came on the scene. Although he was an anti-Darwinian, he introduced the notion, for the first time, that cosmic events may have influenced extinctions. He speculated that the consequences of the explosion of a supernova included increased radiation which, in turn, led to freak mutations in living organisms. These caused overspecialization, including the development of organs unsuitable for survival. Schindewolf synthesized documentations on extinctions, especially those that were relevant for the end-Permian extinction. His influence was considerable in Germany, but did not extend to the English-speaking world. No matter how much evidence he presented to prove that there was no gap in the archaeological record, and that the lack of fossils at the boundary line at the end of the Permian age signified mass extinction, few scientists were willing to listen to his arguments. The evidence from Russia and South Africa had shown that there was no break in the geological processes, and only plants and animal species had disappeared; this, to Schindewolf, signalled a major catastrophe. The discovery of DNA in 1953 and the rapid progress in nuclear biology confirmed Darwinism and undermined Schindewolf’s arguments. In the end he was still proven correct about a major catastrophe occurring 251 million years ago, even if his hypothesis did not provide adequate clues for a mass extinction event.
By the beginning of the 20th century, Lyell’s argument for gradualism was all but undermined. M.W Laubenfels, an American geologist mentioned, in a paper he read in 1956, that the extinction of the dinosaurs 65 million years ago was caused by the impact of a huge meteorite, asteroid or comet. But this was still considered to be a questionable speculation. Until, that is, 1980.
In that year Louis W. Alvarez and his team, including his son, Walter, professor of geology, and their collaborators, Frank Asaro and Helen V. Michel, all of them working at the University of California, Berkeley, published an article in Proceedings of the National Academy of Sciences,13 entitled ”Experimental Evidence that an Asteroid Impact led to the extinction of many species 65 million years ago.” Alvarez was a Nobel Prize winning physicist. The paper opened up a new avenue for research, yet it had very little evidence to support its assertions.14 It stated that the dinosaurs were killed off by the impact of a giant asteroid. Not surprisingly, the paper created an immediate sensation.
Geologists can easily measure the layers of earth and rocks; but their thickness is not necessarily a good indication of elapsed time. A narrow layer of mudstone may mean hundreds of years of slow deposition of fine particles in the oceans’ depths, and a layer of sandstone, 100 yards thick, may mean a catastrophic dumping in minutes or hours. How could such deposits be measured accurately and related to time? Alvarez found an answer in iridium. It is a very rare metal belonging to the platinum group, and it occurs in minute quantities on earth. But it is present in small meteorites, tektites and cosmic dust that settle on the surface. The problem was presented by the dilemma of how to measure such a rare element. Alvarez and his team were able to build a neutron activation machine – he was, after all, a noted physicist – with the necessary precision to do just that.
In the North Italian town of Gubbino, Alvarez and his team obtained rock samples which they subjected to very thorough analysis back in Berkeley. They expected to find iridium in minute quantities, depending on the time during which it accumulated. They found that the concentration of iridium was very low, as expected. However, in their samples from the boundary of the Cretaceous and Triassic periods the volume shot up from the normal 0.3 per billion to 30 times the normal level, to 9 parts per billion! This could mean that the time of the deposits lasted 30 times longer than normal, but it could also mean a sudden catastrophic event, a hit by a giant asteroid!
Alvarez and his team checked another boundary section, this time in Denmark at Stevns Klint. They found an even larger value of 42 parts per billion. This was 160 times the normal level. They calculated the size of an object creating such an explosion that its debris circulated around the earth and the relations between such an object and the energy it would transmit. They based their calculations on huge volcanic eruptions such as the Krakatau event between Java and Sumatra in 1883.
According to their result, a giant meteorite hit the earth 65 million years ago, of the size of about 10 kilometres across, excavating a crater of about 100-150 kilometres of diameter, flinging millions of tons of rocks and dust into the atmosphere. The dust encircled the earth, blocking out the sun for a year or longer, preventing the photosynthesis of plants, cutting off the base of the food chain in the sea and land, and causing mass extinction.
The Alvarez team suggested that the deposits they have measured in Italy and Denmark were not ordinary clay, accumulating in a slow process, but deposits of ash and dust the impact, thrown into the atmosphere, settling down in a few years carrying amounts of iridium that showed its extraterrestrial origin.15
There is no need here to detail the arguments of the Alvarez team for a huge catastrophe 65 million years ago, based on the measurement of iridium in 1 centimetre thick sediments in Italy and Denmark. Their theory would have remained a hotly debated hypothesis without the acquisition of further proof. But proof did indeed come, and soon.
*
Before proof for the Alvarez theory was found, however, another discovery supported his findings. The Bavarian market town of Nördlingen is located in what appears to be a giant crater. The depression measures 22-23 kilometres across and its centre is filled with what appears to be sediments, providing rich farming lands. This is the so-called Ries structure which has puzzled German geologists for some time. Opinions were divided over a huge volcanic eruption in prehistoric times, but there was no cone; it was believed that the volcano either exploded or the cone sunk after the eruption. However, there were no traces of ash or lava flow. There were suggestions of an extraterrestrial impact, but the notion was rejected.16
In 1960, Gene Shoemaker, an astro-geologist of the US Geological Survey, visited Nördlingen. (He is the same man who discovered the Shoemaker-Levy asteroid hitting Jupiter in 1994.) While working in Arizona in a well-known giant meteor crater, Shoemaker and E. C. T. Chao from Washington found an unusual form of quartz, called coesite, which forms under very high pressure of at least 300 kilobars. Only the high energy of a meteorite hitting earth was able to modify normal quartz into coesite, and therefore, it was evidence of an extraterrestrial impact.
Shoemaker and Chao published their findings in Nördlingen in the Journal of Geophysical Research in 1981.17 Their work was so thorough and the evidence they presented so persuasive, that it was never seriously questioned. Geologists flocked to Nördlingen and studied the consequences of the impact. They agreed that the crater originated 14.5 million years ago, and the size of the meteorite was 500-700 meters across. It hit the earth at a speed of 20-60 miles a second. The released energy was the equivalent of 200 megatons, or 200 Hiroshima atomic bombs. The impact threw out 150 cubic kilometres of rock of the crater and every living organism was killed in a radius of 500 kilometres from the centre. The ashes and debris probably circled the earth blocking out the sun’s rays for a few days and causing local extinctions, but this did not last long and was not sufficiently large to have global effects.
The consequence of the discovery was not only the demolition of a century and a half of gradualist notions of earth’s geological history, but also a beginning of a search for other impact craters. But the gradualists did not give up so easily. They offered new arguments according to which the dinosaurs and other extinct animal and plant species were in decline long before the alleged impact of the Alvarez-meteorite at the Cretaceous-Triassic boundary. The decline lasted perhaps as long as five million years. At the end, the reptiles were replaced by mammals. The latter were, of course, Tertiary species, and emerged as the environment changed, the temperature of the earth becoming cooler and the sea levels lower. There were also plants and other animals that continued to exist after the disappearance of the large reptiles, such as turtles, lizards, snakes, crocodiles, frogs, etc, whose survival was hard to explain in light of the impact theory.
These disputes were not simply over reptile extinction, but over “good” and “bad” science. It also involved the reputation of certain sciences, the question was which are more reliable than the others. Physics was considered less speculative than palaeontology, and Alvarez himself was accused of having a superior attitude toward other scientists. It was also a throwback to a long tradition of “gradualism” versus “catastrophism.” The popular media increasingly participated in the debate, and ignorant television anchormen and women were presenting all sorts of outlandish speculations. But the “catastrophists” had an advantage in this debate, since their theories could be used for feeding sensationalism, the bread and butter of television programs.
Finally, in 1991, the crater of the asteroid that caused the mass extinction of 65 million years ago was discovered. It was located in the Yucatan Peninsula, near the Mexican village of Chixculub. It was buried under Tertiary sediments and was invisible from the surface, but boreholes and geophysical evidence showed that originally it was 150 kilometres across, exactly the size which Alvarez and his team predicted.
The discovery was made by Alan Hildebrand, then a Canadian graduate student and his team.18 His research revealed that an asteroid or meteorite struck the earth, evaporated the water and penetrated the Cretaceous lime stones and salt beds. Great boulders were thrown out and fell around the crater. The ashes and dust flew up into the atmosphere and transported iridium around the globe. 65 million years after the impact, there was still a noticeable depression in the earth. Although late Tertiary sediments filled up the crater, geophysical research showed that it originally had a triple-ring structure. The inner ring, produced by the almost immediate spring-back of the earth’s crust, was 80 kilometres in diameter. A zone, extending 100-130 kilometres across, was the original crater’s edge. There was also an outer ring, which probably marks the force-zone of the impact.
*
After this discovery there was no sense in denying the catastrophic impact of an asteroid 65 million years ago, a date confirmed by radiometric dating of the melted rocks. The impact created giant tsunamis and circulated ashes and iridium in the atmosphere. The ash certainly blocked the sun’s rays for over a year, and led to global darkness and freezing temperatures. Photosynthesis in plants stopped, and herbivorous animals starved to death, followed by carnivores who fed on them. There had already been many organisms, animal as well as plant, that were already in decline before the impact, but there were also others that were not affected for one reason or another. This may have been the consequence of ongoing environmental changes. But the extinction was massive; around 50% of all living organisms died out. At the same time, there were a series of volcanic eruptions – perhaps induced by the magnitude of the impact – spewing large amounts of carbon dioxide, sulphur and other poisonous gases into the atmosphere. Their traces were detected in the Deccan Traps of northern India.
In retrospect, it is easy to see the reasons for reluctant geologists and palaeontologists to accept a catastrophic model for the history of the earth. Even today, the evolutionary, gradualist model is still capable of explaining mass extinctions as it was at the time when Lyell “demolished catastrophism.” Yet, evidence of mass extinctions does exist and further research is making the theory more and more convincing. But even the greatest extinction of them all, the one at 251 million years ago, which wiped out nearly 90% of all living things, is still largely shrouded in mystery. However, research continues and it will probably lead to more certain results. This is the nature of modern science.
*
The “greatest extinction of all time,” as Benton described the events of 251 million years ago, was probably not initiated by extraterrestrial events or asteroid strikes. Benton speculated that it was a longer process than the Yucatan impact and it began with a series of huge volcanic basalt eruptions in Siberia. (The slopes of the Ural Mountains near Perm which gave the name to the Permian Age, provide evidence for this series.)19 These eruptions have continued for a considerable time, perhaps even for a half million years. At first, the temperature of the globe increased a little; there may even have been some local cooling because of the large amounts of sulphur dioxide spewed into the atmosphere. In any case, more carbon dioxide came and this produced a general warming effect. A year or more after the first eruptions, a much larger eruption had occurred. Temperatures rose even more. This killed off some plants and the herbivous living off them.
The last large eruptions sent more new gases into the atmosphere and this caused the falling of acid rain. In an area of thousands of square kilometres the acid rain killed off most of the plants. The atmosphere was now several degrees warmer, and began to melt the polar ice around its fringes. The great masses of methane hydrates locked into the sediments at the edges of the polar ice sheet, were also warmed and exploded with a huge force. Giant amounts of methane gas and carbon dioxide burst through the waters, and entered the atmosphere.
This time the catastrophe affected the entire globe. This was a true globalization of climate. Normal levels of oxygen were driven downward by the gases. And there was no end to the process. What made the catastrophe global was the fact that the continents had not yet been separated.
Then came heavy rains of the monsoon. They washed dead trees, plants and animals into the estuaries of the sea. But they also washed away most of the soil, deprived of its protective cover. In a few days, hardly any soil was left on the massive single continent and few animals and other life forms had survived.
Under normal conditions the carbon dioxide would have been removed from the air by the photosynthesis of the plants. But there were hardly any trees or plants left. Even the masses of seaweed died when the acid rain carried the rotting vegetation into the sea and the plankton population had also perished. The oxygen content of the seawater was also gone. Not surprisingly, the fishes that lived off of minute organisms also died, and so did carnivorous sharks. The seas were poisoned and rising temperatures eliminated whatever little oxygen they still contained.
Then a third series of volcanic eruptions came and they added more acid rain to the land. Temperatures rose a little as more and more bubbles of methane gas and carbon dioxide were added to the atmosphere. Oxygen levels had fallen even more in the waters and most life that depended on it died.
The eruptions still continued; hundreds of cubic kilometres of basalt layers were expelled from the depths of the earth. Some explosions were smaller, but others added to the global affects of the previous ones. This process went on for perhaps a half million years, and when it was finally over, barely 10% of living things survived.
This is, as Benton freely admits, only a set of speculations. Yet the fossils that survived from the end-Permian age all point to this astonishing sequence of events. This was the largest of all known extinctions. It was a time when the continents were not yet separated, and the basalt eruptions could affect life on the entire super continent. There were other extinctions at 200, 120, and 90 million years ago, but they caused extinction rates of between 5 and 30%, not nearly as large as that of the end-Permian event. The reason for this may have been the fact that by then the continents were separated and life was better protected in various environments. Benton stated;
…Geologists and palaeontologists are far from understanding, step by step, just what really happened [at the Permian extinction]. But…ideas have been sharpened and focused remarkably since 1995, and will doubtless continue to do so. One thing is clear, however. The biggest mass extinction of all time did happen 251 million years ago and even if it cannot yet be fully explained, it is important to look at the consequences of cutting life down to 10% or even less of its normal diversity. There are lessons here to be learnt20
We might add that the recovery took nearly 50 million years.*
Notes
1
In this process, the American scientists may be considered to have been Europeans, as we shall see below.
2
See for the sermon, the first volume of this work.
3
In the course of the 20th century, the dividing lines were ever narrower; as scientists dwelled into the ”secrets” of the atomic nature of matter, they found ever smaller particles that seemed to obey no rational natural laws. This apparent contradiction was attempted to be solved by the emergence of the “string theory” of ultramodern physics, and the hope of the discovery of a unifying “law of nature.” Whether these concepts will be adequately provable by science still have to be seen., However, some scientists are inclined to accept the notion of a “prime mover,” whether it is called god or nature, as the explanation of the seemingly unexplainable problem.
4
This is the title of a work by Michael J. Benton, When Life nearly died subtitled. The Greatest Mass Extinction of all Time, (London, Thomas and Hudson, 2003), in which the author presents his findings, the basis of the following discussion.
5
Even when a coercive authority attempts to suppress the scientific evidence, as it was the case with astronomy in the course of the fifteenth-sixteenth centuries, or with Lysenkoism in the Soviet Union in the twentieth.
6
Of the many publications of Roderick Murchison and Charles Lyell, see the following: R.M. and A. Keyserling, “On the Geological Structure of the Ural Mountains,” Proceedings of the Geological Society of London, (1842), vol. 3, p. 742-753: and Charles Lyell, Principles of Geology, being an Attempt to Explain the Former Changes of the Earth’s Surface by Reference to Causes now in Operation 3 vols., (London, J. Murray, 1830-1833).
7
Principles of Geology, Being an Attempt to Explain the former Changes of the Earth’s Surface, by reference to Causes now in Operation 3 vols., (London, John MNurray, 1830-1833).
8
Georges Cuvier, Recherches sur les ossemens fossils des quadrupeds, ou l’on rétablit les caractéres de plusieurs d’espéces d’animaux que les revolutions du globe paroissent avoir détruit les espéces, 4 volumes (Paris: G. Dufour et d’Ocagne, 1821-1824), 2nd ed. 1825; 4th ed., 1834-1836.
9
Quoted by Benton, 60-61.
10
The letters are published by A. Geikie, Life of Sir Roderick Murchison, 2 vols. (London, J. Murray, 1875).
11
The latest research had shown that between 70,000 and 80,000 years ago, mankind had also almost disappeared. Matrochondial DNA research shows that something happened at that time, which destroyed nearly all of humankind, leaving not more than at the most 5,000 early humans. There is ongoing research to find the cause of such an extinction, but has not yet uncovered them.
12
See Schindewolf, Grundfragen der Paleontologie. Geologische Zeitmessung – Organische Stammesentwicklung – Biologische Systematik (Stuttgart, Schweizebart, 1950).
13
USA 1980, p. 627-642.
14
Benton noted, that “science does not work by proving cases. That is for lawyers. Scientific theories are the best explanation for the results of a series of observations , but a counter observation might disprove a theory at any time.” Benton, op.cit., 96.
15
See L. W. Alvarez, et al., “Extraterrestrial Cause for the Cretaceous-Tertiary Extinction – Experimental Results and Theoretical Implications,” Science, (1980), p. 1095- 1108., and Alvarez W. , T Rex and the Crater of Doom (Princeton, NJ, Princeton Univ. Press, 1980).
16
Quoted by Benton op.cit., p. 104.
17
E.M. Shoemaker and E.C.T Chao, “New Evidence for the Impact-Origin of the Ries Basin, Bavaria, Germany” vol. 66, pp. 3371-3378.
18
See A. R. Hildebrand et al., “Chixculub Crater: A Possible Cretaceous-Tertiary boundary Impact Crater on the Yucatan Peninsula, Mexico Geology (1991), p. 867-871.
19
Quoted by Benton, op.cit., pp. 277-282. See also, A. Baksi and E. Farrar, “Ar40 and Ar49, Dating of the Siberian Traps, USSR – Evaluation of the Ages of the Two Major Extinction Events Relative to Episodes of Flood-Basalt Volcanism in the USSR and the Deccan Traps (of India)” Geology (1991), vol. 19, p., 461-464.
20
Benton, op. cit., 283.
* This article was part of a longer discussion, presented at the Historical Institute of the Hungarian Academy of Sciences in October, 2003.