A recently-revisited experiment Charles Darwin began nearly 200 years
ago could hold lessons forcreating an environment on Mars that would
sustain life as we know it, some scientists believe.
In 1836, as Charles Darwin's exploratory voyage on the HMS Beagle was nearing an end, he visited the remote volcanic island of Ascension
in the middle of the Atlantic Ocean, 1,000 miles from the coast of Africa and 1,400 miles from South America. A BBC News story by Howard Falcon-Lang
the island's amazing transformation from a land of barren volcanic ash
to a lush oasis where mountain peaks are covered with a "cloud forest"
of pine, eucalyptus, banana and bamboo.David Catling,
a University of Washington professor who studies "astrobiology",
new branch of science concerned with the origin and evolution of life
on Earth, and the possible variety of life beyond Earth, has been
studying Darwin's travels. He thinks Darwin and his friend Joseph
Hooker, a botanist and explorer himself, decided to experiment with
creation of an artificial ecosystem. Working with the British Royal
Navy, and Kew Gardens, where Hooker's father was director, Hooker began
having shiploads of trees sent to Ascension and planted.
An Ascension government website
and a Science Daily story
that the island's original plant life was decimated in the 1500s
because goats released by Portuguese explorers ate most of it. The
subsequent introduction of rabbits, sheep, donkeys and rats continued
the trend. Darwin noticed that Ascension's scant rain evaporated because
there were few plants to hold the moisture. The BBC story explains the
trees on Green Mountain, the highest peak, capture the sea mist that
earned the name cloud forest.
an ecologist at Liverpool John Moores University, who has studied
Ascension's unusual ecosystem, told BBC he had initially been surprised
by the way plants that don't normally belong together were growing
side by side. It is an artificially created ecosystem that developed and
became self-sustaining in decades, rather than centuries. Catling
and Wilkinson think this early experiment in "terra-forming"
may have lessons useful in an effort to create habitable environments on Mars or even elsewhere.
Scientists made another usual recent discovery on the island. The Science Daily
story tells of local conservationists who discovered small sprigs of
parsley fern, declared extinct in 2003 growing on a steep mountainside.
They risked life and limb to nurture the perilously placed plants,
eventually cultivating spores they placed in sterile containers so they
could be flown and then raced by car to Kew Gardens. The survival of the
plants on Ascension and in England was hailed a fitting celebration for
the UN's International Year of Biodiversity. The island is also home to
a seabird restoration project,
begun because the bird populations have been thinned by feral cats, initially imported to get rid of rats.