A celebrated popularizer of science and mathematics, Martin Gardner has devoted much of his life to debunking ESP, ‘psychic’ phenomena, metal-bending and other paranormality. This excerpt is from Science Good, Bad and Bogus (1983).

Politicians, real-estate agents, used-car salesmen, and advertising copy-writers are expected to stretch facts in self-serving directions, but scientists who falsify their results are regarded by their peers as committing an inexcusable crime. Yet the sad fact is that the history of science swarms with cases of outright fakery and instances of scientists who unconsciously distorted their work by seeing it through lenses of passionately held beliefs.

Gregor Johann Mendel, whose experiments with garden peas first revealed the basic laws of heredity, was such a hero of modern science that scientists in the thirties were shocked to learn that this pious monk probably doctored his data. R. A. Fisher, a famous British statistician, checked Mendel’s reports carefully. The odds, he concluded, are about 10,000 to 1 that Mendel gave an inaccurate account of his experiments.

Brother Mendel was a Roman Catholic priest who lived in an abbey in Brünn, now part of Czechoslovakia. More than a century ago, working alone in a monastery garden, he found that his plants were breeding according to precise laws of probability. Later, these laws were explained by the theory of genes (now known to be sections along a helical DNA molecule), but it was Brother Mendel who laid the foundations for what later was called Mendelian genetics. His great work was totally ignored by the botanists of his time, and he died without knowing he would become famous.

Most of the monk’s work was with garden peas. Seeds from dwarf pea plants always grow into dwarfs, but tall pea plants are of two kinds. Seeds from one kind produce only tails. Seeds from the other kind produce both tails and dwarfs. Mendel found that when he crossed true-breeding tails with dwarfs he got only tails. When he self-pollinated these tall hybrids he got a mixture of ¼ true-breeding tails, ¼ dwarfs, and ½ tails that did not breed true.

Today one says that tallness in garden peas is dominant, dwarfness is recessive. Mendel’s breeding experiment is like shaking an even mixture of red and blue beads in a hat, then taking out a pair. The probability is ¼ you will get red-red, ¼ you will get blue-blue, and ½ you will get red-blue. These, however, are ‘long-run’ probabilities. Make such a test just once, with (say) 200 evenly mixed beads, and the odds are strongly against your getting exactly 25 red pairs, 25 blue, and 50 mixed. Statisticians would be deeply suspicious if you reported results that precise.

Mendel’s figures are suspect for just this reason. They are too good to be true. Did the priest consciously fudge his data? Let us be charitable. Perhaps he was guilty only of ‘wishful seeing’ when he classified and counted his tails and dwarfs.

Geologists find strange things in the ground, but none so strange as the ‘fossils’ unearthed by Johann Beringer, a learned professor of science at the University of Würzburg. German Protestants of the early eighteenth century, like so many American fundamentalists today, could not believe that fossils were the relics of life that flourished millions of years ago. Professor Beringer had an unusual theory. Some fossils, he admitted, might be the remains of life that perished in the great flood of Noah, but most of them were ‘peculiar stones’ carved by God himself as he experimented with the kinds of life he intended to create.

Beringer was ecstatic when his teen-age helpers began to dig up hundreds of stones that supported his hypothesis. They bore images of the bodies of strange insects, birds, and fishes never seen on earth. One bird had a fish’s head – an idea God had apparently discarded. Other stones showed the sun, moon, five-pointed stars, and comets with blazing tails. He began to find stones with Hebrew letters. One had ‘Jehovah’ carved on it.

In 1726 Beringer published a huge treatise on these marvelous discoveries. It was written in Latin and impressively illustrated with engraved plates. Colleagues tried to convince Beringer he was being bamboozled, but he dismissed this as ‘vicious raillery’ by stubborn, establishment enemies.

No one knows what finally changed the professor’s mind. It was said that he found a stone with his own name on it! An inquiry was held. One of his assistants confessed. It turned out that the peculiar stones had been carved by two peculiar colleagues, one the university’s librarian, the other a professor of geography.

Poor trusting, stupid Beringer, his career shattered, spent his life’s savings buying up copies of his idiotic book and burning them. But the work became such a famous monument to geological gullery that twenty-seven years after Beringer’s death a new edition was published in Germany. In 1963 a handsome translation was issued by the University of California Press. Beringer has become immortal only as the victim of a cruel hoax.

Was Paul Kammerer the victim of a similar hoax, or was he himself the perpetrator? In any case, when someone applied India ink to (or perhaps injected it into) the feet of several of Kammerer’s frogs, the career of one of the most respected of Viennese biologists was brought to an inglorious end.

Kammerer was the last great champion of a theory of evolution called Lamarckism. In this view, named for the French naturalist Jean Lamarck [see p. 58], acquired traits are somehow passed on to descendants: when giraffes stretched their necks to nibble high leaves, their offspring were born with longer necks. Darwin himself was a Lamarckian. Modern genetics discards this theory, replacing it with the Mendelian view that natural selection operates on variations produced by random mutations.

In 1910 Lamarckism was still the ‘establishment’ view, but the new Mendelian theory was rapidly gaining ground. Eager to defend the older theory (he had written a book about it called The Inheritance of Acquired Characteristics), Kammerer devised a simple experiment with a species of frog known as the ‘midwife toad.’

Most toads mate in water. To keep a firm grip on the female’s slippery body, the male toad develops dark ‘nuptial pads’ on his feet. The male midwife toad, which mates on land, lacks such pads. Kammerer’s scheme was to force midwife toads to copulate under water for several generations, then see if they develop nuptial pads. It was a stupid experiment, because, had it succeeded, Mendelians would have explained it as no more than a revival of a genetic blueprint. Nothing so complicated as a nuptial pad could have developed in just a few generations.

But Kammerer went ahead with his plan and soon reported it to be a huge success. The black pads had indeed appeared. The news was sensational, especially in Russia where Lamarckism then completely dominated biology. Russian scientists were so impressed that they offered Kammerer a post at the University of Moscow.

No sooner had Kammerer accepted this offer than it was discovered that his toad specimens had been crudely faked. It was the biggest science scandal of the decade. Kammerer blamed it all on an assistant, but nobody believed him. In 1926, at age 46, he took a pistol and shot himself through the head.

Kammerer continued to be a great hero in the Soviet Union throughout the period when Joseph Stalin and the plant-breeder Trofim Lysenko, both enthusiastic Lamarckians, saw to it that Mendelian geneticists were banished to Siberia. Now that Lysenko is dead and Soviet genetics has gone Mendelian, it is hard to find a biologist anywhere in the world who takes Lamarckism seriously.