http://www.commondreams.org/headlines01/0508-02.htm
Published on Tuesday,
May 8, 2001 in the Guardian of London
Evolution Is In Our Hands, Say Scientists
Biologists warned to focus on the future, not
the riddles of the past
by James Meek
Evolution scientists today warn of the spread of a global
"pest and weed" environment, with animals and plants
such
as rats, cockroaches, nettles and thistles flourishing
at the expense of more specialized wild organisms.
The scientists say
that, in the next 5 million years,
short-term evolution will favor those species able
to thrive in the margins of human settlement.
They also warned that
decisions made in the next
few decades will determine the fate of 500,000 billion
people, adding that efforts to protect species and
wild habitats now will dictate the future course of
evolution.
In their startling
wake-up call, the group of US, African
and British researchers writing in the US journal, Proceedings
of the National Academy of Sciences, compared the present
mass extinction of species on Earth to past mass extinctions;
then, it took roughly 5 million years for biological diversity
to reassert itself.
"Suppose that
the average number of people on Earth during
the future recovery period is 2.5 billion, by contrast
with the 6 billion today," said two of the scientists,
Norman Myers of Oxford University and Andrew Knoll of Harvard.
"Under these conditions,
the total number of people affected
by what we do - or do not do - during the next few decades
will be in the order of 500 trillion, 10,000 times more
people than have existed until now.
"We are thus engaged
in by far the largest 'decision' every
taken by one human community on the unconsulted behalf of
future societies."
The scientists suggested
that the world is entering a
new period of geological time, the Homogecene, marked
by all parts of the planet increasingly coming to resemble
each other.
David Woodruff, of
the University of California at San Diego,
said that between 3,000 and 30,000 of Earth's estimated
10 million species were disappearing each year.
"We live at a
geological instant when global rates of
extinction are at an all time high for the last 65 million
years, and are increasing," he said.
"The biosphere
will have fewer species and be subject
to more weed, pest and disease outbreaks...the new [habitats]
will be more easily disturbed and invaded, and will have
an aesthetically unappealing dullness."
None of this means
that evolution will stop - just that
it might go in an undesirable direction. "Evolution is
not over - set back perhaps - but by no means over,"
Dr Woodruff said.
Scientists who studied
evolution, he said, were obliged
to abandon their preference for looking backwards and
begin considering the future.
"Some of us advocate
a shift from saving things,
the products of evolution, to saving the underlying
process, evolution itself," he said.
"Like it or not,
evolutionary biologists have to recognize
that the ultimate test of their science is not their
ability to solve the riddles of the past and the origin
of species, but rather to manage their viability and prevent
their premature extinction - to manage the biosphere's future."
Dr Myers said that
much more emphasis should be put on
protecting plants and insects, to protect the evolutionary
pool, rather than on preserving big beasts like tigers or
elephants, which are too few to evolve.
Environmentalists needed
to think not just about saving
the species we have, but about protecting the planet's
ability to generate the species of the future.
"A lot of people
would say, 'no, we don't want creepy
crawlies', but if we lost half the mammals, we could
get by," DR Myers said.
"If we lost half
of all insects, with their pollinating
function, our agriculture would be in trouble in just a
few seasons.
"We live at a
time when, in just the next two decades,
we can save some very fundamental processes. If we do that,
I think we will be thanked by hundreds of thousands of
generations to come, and if we don't, we will be criticized
for millions of years."
Going
Hamilton frogs
One of the rarest frogs
in the world, Hamilton frogs are small
amphibians endemic to Stephens Island in the Cook Strait,
New Zealand. First discovered in 1915, about 200 exist.
Their future is threatened by stoat invasions
Hawaiian fern
Only one single Diplazium
molokaiensis, a member of the wood fern
family, has been found in Hawaii during the past two decades,
and the species' extinction seems inevitable
Alabama sturgeon
Endangered after a
reduction of at least 80% of the population
in 10 years. Overfishing, and loss of habitat to blame
Gone
Dusky seaside
sparrow
Became extinct in 1987.
It is widely considered to be the
most recent, well-documented extinction of a vertebrate
in the US. Disappearance due entirely to the loss of a
natural habitat, the Everglades
Golden Toad
Discovered in Monteverde,
Costa Rica, in 1963. Despite being
protected, it was presumed extinct when by 1989 the one lone
male disappeared
Charco Palma
pupfish
Due to falling levels
of essential water, the Charco Palma
pupfish became extinct in 1994. The species was found at a
single spring, Charco La Palma, Aramberri, southern Nuevo León,
Mexico.
The 50-70 pupfish disappeared
when the spring water was used
for human consumption and for irrigation
© Guardian Newspapers
Limited 2001
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