Charles Darwin was a gifted naturalist, a prolific writer and author, and one of the most important figures in the history of science. Born on February 12th 1809 in Shropshire, England, he was grandson to Erasmus Darwin - a famous natural philosopher, and Josiah Wedgwood - known for the industrialization of the production of pottery.

Darwin's scientific career began in 1825 as an apprentice doctor moved home to Scotland in order to study medicine at Edinburgh University. However, Darwin became disinterested in this subject and neglected his medical studies to spend time on his latest fascination for taxonomy - the classification of living things, and marine invertebrates. In 1828, Darwin was sent to Cambridge with the intention of studying for a Bachelor of Arts, but once again his focus became diverted, concentrating his energies on beetle collecting, botany, geology and natural philosophy.

Perhaps the cornerstone event of Darwin's life was a five year voyage around the world on the ship HMS Beagle. This voyage took place between 1831 and 1836, and while the ship's primary mission was to survey and chart coasts to survey and chart the South American coastlines, Darwin was able to study the geology of areas visited, and amass a vast collection of natural history specimens.

Darwin's voyage on the Beagle, was probably the main inspiration for his later ideas. Of these, the most important and best known, was his theory of evolution by natural selection. Although, evolutionary ideas had been common since at least the 18th century, Darwin was able to describe how the process of natural selection (Darwin's theory of how which evolution occurred) by presenting overwhelming arguments and clear evidence of his position. This path of scientific discovery was backed by extensive 'evolution-based' experimentation.

Most of his experimental work on plants, worms, and barnacles has been well documented - including being published by the great man himself. However, there is one little-known experiment that Darwin undertook, The results of which could be truly ground breaking with regards to securing a future of our planet. It is also an experiment that surprisingly is still ongoing. The subject of this study was terraforming - something that would perhaps be more fitting in a science fiction movie! The story of Charles Darwin's greatest experiment is as follows:

Charles Darwin and Ascension Island

Back in 1836, the young Charles Darwin was coming to the end of his five-year survey mission on the HMS Beagle. Whilst aboard HMS Beagle, he called in on St Helena, an island of volcanic origin situated in the South Atlantic Ocean. Its existence - as well as that of Ascension Island - depends entirely on what geologists call the mid-Atlantic ridge. This is a chain of underwater volcanoes formed as oceanic plates are wrenched apart.

It was previously in possession of the East India Company while Napoleon I was in exile there, but after his death in 1821, control of St Helena was passed from the East India Company to the British Crown. It was now an important and strategic British naval station

Darwin wasn't expecting much upon his arrival at St Helena, and even less for his next port of call.

'We know we live on a rock, but the poor people of Ascension live on a cinder.' Joked one of residents of St Helena before his departure.

When Darwin reached Ascension Island he described it as an arid treeless island, with nothing growing near the coast. Everywhere, bright red volcanic cones and rugged black lava signalled the violent forces that had wrought the island. However, the sparse vegetation inland did manage to support...

‘...about six hundred sheep, many goats, a few cows and horses, and large numbers of guinea fowl imported from the Cape Verde islands, as well as rats, mice and land crabs...’

Darwin also noted the care taken to sustain the houses, gardens and fields with good drinking water. These natural springs were carefully managed...

' that a single drop of water may not be lost: indeed the whole island may be compared to a huge ship kept in first-rate order.'

In commenting on this, he noted René Primevère Lesson's remark

‘...that the English nation alone would have thought of making the island of Ascension a productive spot; any other people would have held it as a mere fortress in the ocean...’

And he was right because the Navy was extremely serious about expanding. The trouble was that this shortage of fresh water was a serious problem as it impeded any further expansion by the Royal navy of this prized, imperial outpost. Luckily, a rather cunning plan was beginning to hatch at the back of Darwin's mind. A plan that would that could change the entire Island ecology, environment and climate!

In 1843, botanist, explorer, and future Director of the Royal Botanic Gardens at Kew Joseph Hooker also visited the island. Then four years later, Hooker - with a great deal of persuasion and encouragement from Darwin - advised the Royal Navy that with the help of Kew Gardens, they should institute a long term plan of shipping trees to Ascension. Darwin's idea was fantastically simple, and a true insight into his genius. Trees would capture more rain, reduce evaporation and create rich, loamy soils. The 'cinder island' wasn't just to be an enormous, government funded garden. Charles Darwin, Kew Gardens and the Royal Navy had conspired to build a fully functioning, but totally artificial ecosystem!

So, from 1850 and continuing year on year, ships came each depositing a varied assortment of plants from botanical gardens in Argentina, Europe and South Africa. And it didn't take long, soon, on the highest peak at 859m (2,817ft), great changes were afoot. By the late 1870s, Norfolk pines, eucalyptus, bamboo, and banana trees were in lush profusion at the highest point of the island, Green Mountain, creating a tropical cloud forest.

Professor David Catling of the University of Washington, Seattle, is retraced Darwin's travels for a book he was writing. He tells of a letter that was awaiting Darwin on his arrival at Ascension Island from his Cambridge mentor, John Henslow.

'Darwin's voyage of discovery had already caused a huge sensation in London.' explains Catling. 'In this letter Henslow had assured him that on his return, he would take his place among the great men of science.'

How right he would be. Yet could Darwin's secret garden have more far-reaching consequences?

Dr Dave Wilkinson is an ecologist at Liverpool John Moores University, who has written extensively about Ascension Island's strange ecosystem. He had the following to say during a recent interview with the BBC.

'I remember thinking, this is really weird.There were all kinds of plants that don't belong together in nature, growing side by side. I only later found out about Darwin, Hooker and everything that had happened.'

Darwin's artificial forest captures moisture from clouds that drift over Ascension's peaks creating a damp oasis where there was once just aridity. Dr Wilkinson likes to describe the forest vegetation of Green Mountain - Ascensions highest peak - as a 'cloud forest'.

Such ecosystems normally develop over million of years through a slow process of coevolution. By contrast, the Green Mountain cloud forest was cobbled together by the Royal Navy in a matter of decades.

Dr Wilkinson exclaimed: 'This is really exciting! What it tells us is that we can build a fully functioning ecosystem through a series of chance accidents or trial and error.'

Wilkinson thinks that the principles that emerge from that experiment could be used to transform future colonies on Mars. In other words, rather than trying to improve an environment by force, the best approach might be to work with life to help it 'find its own way'. However, to date, scientists have been deaf to the parable of Ascension Island.

'It's a terrible waste that no-one is studying it.' remarked Wilkinson at the end of the interview.

It seems that Ascension Island's secret will be safe for years to come or - with current concerns of climate change, deforestation and recent evidence of increased extinctions - will Darwin's greatest experiment help to save us all?

For related articles click onto the following links:

No comments: