What will the animal population of planet earth look like a thousand years from now? The answer depends both on natural processes and human choice.
Animals will have to be more adaptable if humans continue to increase and take over earth’s eco-system. They will be forced to migrate into the increasingly shrinking habitats that human don’t want. Those who cannot be exploited for human use may be squeezed into extinction.
Climate change presents another challenge. Any animal which cannot adapt to changes in habitat may soon exist only in zoos or parks. The bio-diversity of the earth is decreasing at an alarming rate as species are lost as a result of human expansion. Will the processes of nature counter this trend by the emergence of new species? Since everything is inter-related, the long-term consequences of these changes are difficult to predict.
The process of evolution is not as well-understood as we imagined half a century ago. There is increasing evidence that our model of very gradual change through natural selection is not the whole story. In his book, “The Evolution Explosion”, Stephen Palumbi notes that species evolve with astounding rapidity when their survival is at stake. The beaks of finches on the Galapagos Islands expand and shrink as weather conditions change the supply of seeds they eat. Male Trinidian guppies will quickly lose their flashy female-attracting red spots in a pond full of predators, but if the predators disappear, the sexy colors re-evolve. In only 50 years, pink salmon in the Pacific Northwest have responded to fishing pressure by evolving to be two-thirds of the size of their ancestors.
The use of pesticides continues to put pressure on insect populations to evolve. The few individuals that survive poisoning will be the ones that breed and pass on their resistance. The use of technology to create new and better poisons and genetically-engineered plants which are poisonous or unpalatable to insects, is a Pandora’s Box whose contents can only be guessed. The super-resistant insects may have unforeseen characteristics which will influence the rest of the ecosystem.
Bacteria evolve even faster than insects. Medicines which were “miracle drugs” thirty years ago are ineffective against new strains of antibiotic-resistant bacteria. Since many food animals are routinely fed antibiotics, the same thing is happening to them. “Superbugs” evolve while the animals’ immune systems are weakened from lack of challenge. Some bacteria and viruses affect a variety of species. The universal race for survival is common to the whole web of life. Without balance, all are threatened.
At no time in history has human choice been so critical to evolution. We are capable of immediate and direct interference in the evolutionary process through genetic engineering. Genetically modified chickens are food production machines devoid of their survival instincts, incapable of foraging for themselves. Genetically altered farmed fish which escape into open water may interbreed with or displace the wild population. If biological art forms such as neon bunnies catch on, it is only a matter of time until they have the opportunity to pass on their genes. Genetic alterations to animals to make their organs better suited for transplantation to humans raises some serious ethical problems. In his novel “Next”, Michael Crichton postulates the possibility of animals genetically engineered to carry advertising, and talking apes who have been modified with human genes. Today’s science fiction could become tomorrow’s reality.
If our species, homo sapiens sapiens, is decimated or destroyed, the eco-system will undergo a radical revolution as other species reclaim human habitats. A new dominant species may evolve – perhaps even one of the offspring of human interference in the ancient processes of nature.
Human-caused evolutionary change
A review of Michael Chrichton’s novel “Next”