1809 – 1881

THE spark for Darwin’s accomplishments was ignited with the 1831 HMS Beagle expedition, which was to chart coastlines in the South Americas and other areas of the Pacific. Darwin, supposedly studying religion at the time, had become increasingly absorbed with natural history and persuaded the Professor of Botany, John Henslow, to put him forward for the post of unpaid naturalist on the Beagle’s voyage. He thereby abandoned his university studies. His father, and initially the vessel’s Captain FitzRoy, resisted, but he eventually persuaded them to let him take part in the five-year expedition.

 

DURING the journey, Darwin made many geological and biological observations, but it was his time spent around the Galapagos Islands which would end up having the most significant impact on him. The ten islands are relatively isolated, even from each other, and as such act as a series of distinct observatories through which Darwin could draw comparisons. He noted that the islands shared many species of flora and fauna in common, but that each land mass often displayed distinct variations within the same group of organisms. For example, he famously noted fourteen different types of finch across the islands, notably with different shaped beaks. In each instance the particular beak seemed to best suit the capture of that bird’s prevalent food source, whether it be seeds, insects or fish.

Over the ensuing years, and upon his return to England, Darwin pondered on the reasons for the variations in the finches and other plants and animals. He soon surmised that the birds had descended from a single parent species, rather than each springing up independently. From this, he acknowledged the idea of evolution, a concept which had existed for some time but was not widely accepted. Darwin began looking for an explanation for this evolution. One text which had a particular impact on him was Thomas Malthus’s 1798 work An Essay on the Principle of Population which Darwin read in 1838. Malthus had been concerned with overpopulation resulting in famine, and the possible competition for food which would ensue. Darwin immediately saw that this could also be applied to the animal world too, where only those best adapted to food collection in their environments would survive. Those that could not compete would die out and the characteristics of the successful animals, which may have occurred in the first place by chance, would be passed onto future generations. As environments changed and animals moved about, success criteria would change, gradually resulting in variations within species, as had happened with the finches. Ultimately, new species would also be created.

 

UNFORTUNATELY, such a hypothesis would challenge the commonly held view of man as the lord of the earth, specifically created and placed upon the planet in God’s image – as described in Genesis in the Bible. Darwin was implicitly suggesting that man had evolved by chance over thousands of years. He correctly anticipated uproar and resistance to his ideas, particularly from religions leaders. Consequently, he kept his theories dark for twenty years while he gathered additional evidence to back up his case.

He finally published in 1858. He did this jointly with Alfred Russell Wallace (1823–1913), whose independent ideas were remarkably similar to Darwin’s. They agreed to a joint public declaration of their hypotheses by submission of a paper to the Linnean Society. Darwin followed this up with a more detailed account in 1859 containing evidence he had collected over the previous decades called On The Origin of Species by Means of Natural Selection.

The predicted outcry ensued and a fierce debate followed, but Darwin already had a number of close associates, particularly Thomas Huxley, known as ‘Darwin’s Bulldog’, who would vigorously defend his ideas. This left Darwin free to follow through further implications of his hypothesis in other works, including the 1871 text The Descent of Man, which articulated the idea of the evolution of the human race from other creatures.

THE LEGACY OF DARWIN

Darwin’s ideas took a long time to become generally accepted (even today they are not embraced by everyone), challenging as they did all previous conceptions of what is meant to be human.

As has been the case with so many scientists, he encountered particularly fierce opposition from the Church, whose members preferred the safety of a sacred text to the uncertainties of observation and experiment.

The idea of evolution through natural selection is, however, at the heart of modern biology. The man who disappointed his father for lack of academic interest had eventually gone on to turn an entire branch of academia on its head.

CHRONOLOGY

. 1831–36 Darwin takes the job of unpaid naturalist aboard HMS Beagle

. 1859 Publishes The Origin of Species

. 1871 Publishes The Descent of Man

. 1881 Dies and is buried at Westminster Abbey

. See also Quantum Leaps: ‘Galileo Galilei’…

RELATED: THOMAS MALTHUS

Previously written by the site author and filed on November 23, 2007 on another domain:

The Concept of ‘Overpopulation’

In 500 BC, the Chinese philosopher Han Fei–Tzu wrote:

…“In ancient times, people were few but wealthy and without strife. People nowadays think that five sons are not too many. Each son has five sons too and before the grandfather dies there are already 25 descendants. Therefore, people are more and wealth is less; they work hard and receive little. The life of a nation depends on having enough food, not upon the number of people.”

 

THIS is the earliest known comment on birth rates and population growth, and the earliest statement of the concept of over-population.

They were ideas that would return again and again in antiquity. Aristotle emphasized the need for food production to keep pace with population growth:

“When there are too many farmers the excess will be of the best kind; when there are too many labourers and mechanics, it will be of the worst kind.”

The concerns of the philosophers were justified. The population of the world grew steadily from 3-million in 10,000 BC to 250-million by the time of Christ.

Malthus concluded that the poor-law system at the time in England, with its indiscriminate doles given to large families, was actually destructive rather than helpful. Saying so seemed, and to many still seems, heartless and illiberal but it was an honest inference logically arrived at. It was not surprising then that his book provoked a storm of controversy. Malthus offered readers the hope that the birth rate might be reduced by sexual abstinence and the use of birth control – and reducing the birth rate was the answer.

 

IN MODERN TIMES the person who did most to draw attention to the dangers of overpopulation was Thomas Malthus. In 1798, at the age of 32, he published his great work, ‘Essay on the Principle of Population.’ In this landmark book, Malthus maintained that optimistic views regarding population are groundless, and that population has a tendency to increase faster than the means of maintaining it. Food production increases at an arithmetic rate; population increases at a geometric rate. In other words, human population will go on increasing until there is no food left, or until there is some other check, such as pestilence or war, and then collapse through famine.

But was Malthus wrong? Writing at the end of the eighteenth century, he was unaware of the effects that improved transport in the form of steamships and railways would have. He was unaware that colonization of new regions would open up new areas to food production. As a result, the population collapse he predicted was long delayed. He may not have been wrong in the long term, of course – only wrong for the nineteenth and twentieth centuries.

The ideas of Malthus also lay behind the scare-mongering that went on in the 1960s and 1970s, when many influential economists and ecologists argued that human population growth was running out of control – that starvation lay just round the corner. The simple Malthusian model may work well for organisms that depend on a narrow range of foods, but the human race is far more complicated than that. People have been able to develop new high-yield strains of wheat, rice and other key foods, so that the food supply is more elastic than once thought. The over-population scare campaigns of the 1960s and 70s nevertheless generated a great deal of interest in population control, and most countries now have more or less effective birth control programmes in place. Some countries, such as Singapore, have found that their attempts to reduce the birth rate were too effective and they now need to encourage people to have more children in order to meet all their labour needs.