The Wonders of Biodiversity
Recently some 150 scientists from around the Pacific gathered in Auckland to research and if possible prevent the extinction of some tiny creatures of no known economic importance. How important is it for us to protect even the smallest of organisms from ‘alien invaders’, or from the destruction of their habitat? Science is increasingly becoming aware that our habitat is a most intricate web of interdependent creatures every one of which is connected to the survival of some other.
The fragile balance of our plants and animals has taken over 80 million years to develop. Over the last 500 million years there have been several mass extinctions of life through natural disasters, the last one about 85 million years ago when a meteor crashed into the earth and initiated a violent change of climate.
Since then, through God’s creative power, there have slowly evolved richly diverse forms of life in self-regulating harmony. This harmony has given rise to James Lovelock’s Gaia hypothesis of our earth being a self-regulating organism. He has been led to this by his atmospheric research. It resulted in the discovery that the thin layer of air which envelops us has remained consistently within the parameters necessary to sustain life. Flora and fauna of land and sea have consistently balanced out major cosmic disturbances.
Over 5 million species worldwide have been identified to date and the numbers yet to be discovered can only be guessed at but many will be extinct before they can be found. For our generation is the first one to witness a mass extinction through human activity. We have accelerated the natural rate of dying out by 100 to 1000 times. Thousands of creatures disappear every year through human influences.
By placing us above all other forms of life, the book of Genesis has given us grave responsibilities, for biologically we are no more than a link in the intricate web of life, be it with the gift of choice.
The consequences of the reduction in the earth’s biodiversity have only begun to be fully realized. National Geographic comments: ‘The web of life connects the smallest bacterium to the giant redwood tree and the whale. When we put that web in peril we become agents of calamity’.
The fact that we know so little about most species on earth is a compelling argument for protecting biodiversity. We know about the web of life, but every time our scientists study a small link in it they discover what seem to be endless interconnections. The more we learn the more we find how much else we have to discover.
Ian Lowe of Griffith University in Australia gives an example of the unpredictable interconnectedness of life’s components. In a study of truffles that grow in the dry eucalyptus forest in New South Wales, it was found that the truffles perform a service for the trees near which they are found. Because both truffles and trees extract water and minerals from the soil, trees with truffles in their roots obtain more water and minerals and grow better than those without. The truffles are the favourite food of the marsupial poteroo, now classified as rare, which then excretes the spores of the truffles and thereby enhances the health of the forest. Poteroo, truffle and eucalypt, three very different species of mammal, fungus and plant, all bound together in a remarkable web of interdependence.
Or we could look at the process of regeneration of our native forest after a natural disaster. The bare rock faces, after a landslide in the Buller Gorge, could not have recovered their native verdancy had their damp surfaces not first become host to micro-organisms, followed by lichens and mosses which we often scorn and sandblast in our domestic environment
Tropical forests harbour more than half of all species. But only half of the original forest cover is left, and much of it has been altered by human activity so it no longer resembles its pristine form.
We have devoted people who dedicate their lives to the rescue of threatened creatures. They do not ask if the bird, the plant or the snail they care for is useful to us. To them each life form is of intrinsic value and needs to be respected
New Zealand’s flora and fauna has developed in isolation over some 80 million years with the result that over 80% of our plant species are unique to our islands. It is fortunate that we have ecologists and politicians who are aware of our responsibility to save our remaining forests from further destruction. We also have devoted people who dedicate their lives to the rescue of threatened creatures. They do not ask if the bird, the plant or the snail they care for is useful to us. To them each life form is of intrinsic value and needs to be respected
Recognising that the diversity of species is an evolutionary survival strategy within the planet’s many ecosystems, it is equally important to understand that genetic diversity within each species is essential for giving it the resilience to cope with changing conditions. Our domesticated plants and animals, wild only 10 000 to 12 000 years ago, had evolved with this diversity. We are abandoning this now with our propensity for breeding from single strains selected with a view to immediate profit. While the resultant sterility of seeds is a boon for seed merchants, the increase in many ills of plants and animals, due to lack of stamina and adaptability, gives employment to our scientists but is never traced back to fundamental causes.
We are slowly learning our lesson. Our border controls are vigilant against deliberate or inadvertent introduction of ‘alien creatures’. There is no certain way to predict the kind of impact an introduced organism may have on our ecosystem.
When the powerful chemical companies try to convince us of the benefits of genetic engineering, which, if used in strict confinement may have a useful function, it is well worth remembering that their products when grown in the field are the most insidious form of alien invasion to threaten our ecosystem. We can avoid the often-cited health risks if we chose to eat GE-free food. But environmental degradation from field-grown genetically modified organisms is unstoppable. Unlike rabbits, possums, gorse or blackberry, introduced genes can never be eradicated. Sadly, we must now extend our vigilance from our borders to the threat from within.