came out best in the struggle for survival.”
“That sounds logical.”
“But this was actually the universal mechanism that Darwin had been searching for. Here was the explanation of how evolution happens. It was due to natural selection in the struggle for life, in which those that were best adapted to their surroundings would survive and perpetuate the race. This was the second theory which he proposed in The Origin of Species. He wrote: The elephant is reckoned the slowest breeder of all known animals,’ but if it had six young and survived to a hundred, ‘after a period of from 740 to 750 years there would be nearly nineteen million elephants alive, descended from the first pair.’ “
“Not to mention all the thousands of cods’ eggs from a single cod.”
“Darwin further proposed that the struggle for survival is frequently hardest among species that resemble each other the most. They have to fight for the same food. There, the slightest advantage—that is to say, the infinitesimal variation—truly comes into its own. The more bitter the struggle for survival, the quicker will be the evolution of new species, so that only the very best adapted will survive and the others will die out.”
“The less food there is and the bigger the brood, the quicker evolution happens?”
“Yes, but it’s not only a question of food. It can be just as vital to avoid being eaten by other animals. For example, it can be a matter of survival to have a protective camouflage, the ability to run swiftly, to recognize hostile animals, or, if the worst comes to the worst, to have a repellent taste. A poison that can kill predators is quite useful too. That’s why so many cacti are poisonous, Sophie. Practically nothing else can grow in the desert, so this plant is especially vulnerable to plant-eating animals.”
“Most cacti are prickly as well.”
“The ability to reproduce is also of fundamental importance, obviously. Darwin studied the ingenuity of plant pollination in great detail. Flowers glow in glorious hues and exude delirious scents to attract the insects which are instrumental in pollination. To perpetuate their kind, birds trill their melodious tones. A placid or melancholy bull with no interest in cows will have no interest for genealogy either, since with characteristics like these, its line will die out at once. The bull’s sole purpose in life is to grow to sexual maturity and reproduce in order to propagate the race. It is rather like a relay race. Those that for one reason or another are unable to pass on their genes are continually discarded, and in that way the race is continually refined. Resistance to disease is one of the most important characteristics progressively accumulated and preserved in the variants that survive.”
“So everything gets better and better?”
“The result of this continual selection is that the ones best adapted to a particular environment—or a particular ecological niche—will in the long term perpetuate the race in that environment. But what is an advantage in one environment is not necessarily an advantage in another. For some of the Galapagos finches, the ability to fly was vital. But being good at flying is not so necessary if food is dug from the ground and there are no predators. The reason why so many different animal species have arisen over the ages is precisely because of these many niches in the natural environment.”
“But even so, there is only one human race.”
“That’s because man has a unique ability to adapt to different conditions of life. One of the things that amazed Darwin most was the way the Indians in Tierra del Fuego managed to live under such terrible climatic conditions. But that doesn’t mean that all human beings are alike. Those who live near the equator have darker skins than people in the more northerly climes because their dark skin protects them from the sun. White people who expose themselves to the sun for long periods are more prone to skin cancer.”
“Is it a similar advantage to have white skin if you live in northern countries?”
“Yes, otherwise everyone on earth would be dark-skinned. But white skin more easily forms sun vitamins, and that can be vital in areas with very little sun. Nowadays that is not so important because we can make sure we have enough sun vitamins in our diet. But nothing in nature is random. Everything is due to infinitesimal changes that have taken effect over countless generations.”
“Actually, it’s quite fantastic to imagine.”
“It is indeed. So far, then, we can sum up Darwin’s theory of evolution in a few sentences.”
“Go ahead!”
“We can say that the ‘raw material’ behind the evolution of life on earth was the continual variation of individuals within the same species, plus the large number of progeny, which meant that only a fraction of them survived, the actual ‘mechanism,’ or driving force, behind evolution was thus the natural selection in the struggle for survival. This selection ensured that the strongest, or the ‘fittest,’ survived.”
“It seems as logical as a math sum. How was The Origin of Species received?”
“It was the cause of bitter controversies. The Church protested vehemently and the scientific world was sharply divided. That was not really so surprising. Darwin had, after all, distanced God a good way from the act of creation, although there were admittedly some who claimed it was surely greater to have created something with its own innate evolutionary potential than simply to create a fixed entity.”
Suddenly Sophie jumped up from her chair.
“Look out there!” she cried.
She pointed out of the window. Down by the lake a man and a woman were walking hand in hand. They were completely naked.
“That’s Adam and Eve,” said Alberto. “They were gradually forced to throw in their lot with Little Red Rid- inghood and Alice in Wonderland. That’s why they have turned up here.”
Sophie went to the window to watch them, but they soon disappeared among the trees.
“Because Darwin believed that mankind was descended from animals?”
“In 1871 Darwin published The Descent of Man, in which he drew attention to the great similarities between humans and animals, advancing the theory that men and anthropoid apes must at one time have evolved from the same progenitor. By this time the first fossil skulls of an extinct type of man had been found, first in the Rock of Gibraltar and some years later in Neanderthal in Germany. Strangely enough, there were fewer protests in T871 than in 1859, when Darwin published The Origin of Species. But man’s descent from animals had been implicit in the first book as well. And as I said, when Darwin died in 1882, he was buried with all the ceremony due to a pioneer of science.”
”So in the end he found honor and dignity?”
“Eventually, yes. But not before he had been described as the most dangerous man in England.”
“Holy Moses!”
“ ‘Let us hope it is not true,’ wrote an upper-class lady, ‘but if it is, let us hope it will not be generally known.’ A distinguished scientist expressed a similar thought: ‘An embarrassing discovery, and the less said about it the better.’ “
“That was almost proof that man is related to the ostrich!”
“Good point. But that’s easy enough for us to say now. People were suddenly obliged to revise their whole approach to the Book of Genesis. The young writer John Ruskin put it like this: ‘If only the geologists would leave me alone. After each Bible verse I hear the blows of their hammers.’ “
“And the blows of the hammers were his doubts about the word of God?”
“That was presumably what he meant. Because it was more than the literal interpretation of the story of creation that toppled. The essence of Darwin’s theory was the utterly random variations which had finally produced Man. And what was more, Darwin had turned Marv into a product of something as unsentimental as the struggle for existence.”
“Did Darwin have anything to say about how such random variations arose?”
“You’ve put your finger on the weakest point in his theory. Darwin had only the vaguest idea of heredity. Something happens in the crossing. A father and mother never get two identical offspring. There is always some slight difference. On the other hand it’s difficult to produce anything really new in that way. Moreover, there are plants and animals which reproduce by budding or by simple cell division. On the question of how the variations arise, Darwin’s theory has been supplemented by the so-called neo-Darwinism.”
“What’s that?”
“All life and all reproduction is basically a matter of cell division. When a cell divides into two, two identical cells are produced with exactly the same hereditary factors. In cell division, then, we say a cell copies itself.”
“Yes?”
“But occasionally, infinitesimal errors occur in the process, so that the copied cell is not exactly the same as
