Evans had in fact discovered an entire civilisation, one that was completely unknown before and could claim to have been produced by the first civilised Europeans. He named the civilisation he had discovered the Minoan because of the references in classical writers and because although these Bronze Age Cretans worshipped all sorts of animals, it was a bull cult, worship of the Minotaur, that appeared to have predominated. In the frescoes Evans discovered many scenes of bulls – bulls being worshipped, bulls used in athletic events and, most notable of all, a huge plaster relief of a bull excavated on the wall of one of the main rooms of Knossos Palace.
Once the significance of Evans’s discoveries had sunk in, his colleagues realised that Knossos was indeed the setting for part of Homer’s Odyssey and that Ulysses himself goes ashore there. Evans spent more than a quarter of a century excavating every aspect of Knossos. He concluded, somewhat contrary to what he had originally thought, that the Minoans were formed from the fusion, around 2000 B.C., of immigrants from Anatolia with the native Neolithic population. Although this people constructed towns with elaborate palaces at the centre (the Knossos Palace was so huge, and so intricate, it is now regarded as the Labyrinth of the Odyssey), Evans also found that large town houses were not confined to royalty only but were inhabited by other citizens as well. For many scholars, this extension of property, art, and wealth in general marked the Minoan culture as the birth of Western civilisation, the ‘mother culture’ from which the classical world of Greece and Rome had evolved.34
Two weeks after Arthur Evans landed in Crete, on 24 March 1900, the very week that the archaeologist was making the first of his great discoveries, Hugo de Vries, a Dutch botanist, solved a very different – and even more important – piece of the evolution jigsaw. In Mannheim he read a paper to the German Botanical Society with the title ‘The Law of Segregation of Hybrids.’
De Vries – a tall, taciturn man – had spent the previous years since 1889 experimenting with the breeding and hybridisation of plants, including such well-known flowers as asters, chrysanthemums, and violas. He told the meeting in Mannheim that as a result of his experiments he had formed the view that the character of a plant, its inheritance, was ‘built up out of definite units’; that is, for each characteristic – such as the length of the stamens or the colour of the leaves – ‘there corresponds a particular form of material bearer.’ (The German words was in fact Träger, which may also be rendered as ‘transmitter.’) And he added, most significantly, ‘There are no transitions between these elements.’ Although his language was primitive, although he was feeling his way, that night in Mannheim de Vries had identified what later came to be called genes.35 He noted, first, that certain characteristics of flowers – petal colour, for example – always occurred in one or other form but never in between. They were always white or red, say, never pink. And second, he had also identified the property of genes that we now recognise as ‘dominance’ and ‘recession,’ that some forms tend to predominate over others after these forms have been crossed (bred). This was a major discovery. Before the others present could congratulate him, however, he added something that has repercussions to this day. ‘These two propositions’, he said, referring to genes and dominance/recession, ‘were, in essentials, formulated long ago by Mendel…. They fell into oblivion, however, and were misunderstood…. This important monograph [of Mendel’s] is so rarely quoted that I myself did not become acquainted with it until I had concluded most of my experiments, and had independently deduced the above propositions.’ This was a very generous acknowledgement by de Vries. It cannot have been wholly agreeable for him to find, after more than a decade’s work, that he had been ‘scooped’ by some thirty years.36
The monograph that de Vries was referring to was ‘Experiments in Plant-Hybridisation,’ which Pater Gregor Mendel, a Benedictine monk, had read to the Brünn Society for the Study of Natural Science on a cold February evening in 1865. About forty men had attended the society that night, and this small but fairly distinguished gathering was astonished at what the rather stocky monk had to tell them, and still more so at the following month’s meeting, when he launched into a complicated account of the mathematics behind dominance and recession. Linking maths and botany in this way was regarded as distinctly odd. Mendel’s paper was published some months later in the Proceedings of the Brünn Society for the Study of Natural Science, together with an enthusiastic report, by another member of the society, of Darwin’s theory of evolution, which had been published seven years before. The Proceedings of the Brünn Society were exchanged with more than 120 other societies, with copies sent to Berlin, Vienna, London, St Petersburg, Rome, and Uppsala (this is how scientific information was disseminated in those days). But little attention was paid to Mendel’s theories.37
It appears that the world was not ready for Mendel’s approach. The basic notion of Darwin’s theory, then receiving so much attention, was the variability of species, whereas the basic tenet of Mendel was the constancy, if not of species, at least of their elements. It was only thanks to de Vries’s assiduous scouring of the available scientific literature that he found the earlier publication. No sooner had he published his paper, however, than two more botanists, at Tubingen and Vienna, reported that they also had recently rediscovered Mendel’s work. On 24 April, exactly a month after de Vries had released his results, Carl Correns published in the Reports of the German Botanical Society a ten-page account entitled ‘Gregor Mendel’s Rules Concerning the Behaviour of Racial Hybrids.’ Correns’s discoveries were very similar to those of de Vries. He too had scoured the literature – and found Mendel’s paper.38 And then in June of that same year, once more in the Reports of the German Botanical Society, there appeared over the signature of the Viennese botanist Erich Tschermak a paper entitled ‘On Deliberate Cross-Fertilisation in the Garden Pea,’ in which he arrived at substantially the same results as Correns and de Vries. Tschermak had begun his own experiments, he said, stimulated by Darwin, and he too had discovered Mendel’s paper in the Brünn Society Proceedings.39 It was an extraordinary coincidence, a chain of events that has lost none of its force as the years have passed. But of course, it is not the coincidence that chiefly matters. What matters is that the mechanism Mendel had recognised, and the others had rediscovered, filled in a major gap in what can claim to be the most influential idea of all time: Darwin’s theory of evolution.