As we consider what science might accomplish in the 21st century and/or what we expect of science in the 21st century, I would like to share some thoughts with you. I was loaned a book a short while ago which reviews the events and mysteries of evolution. The book, Blueprints by Maitland A Edey and Donald C. Johanson, is worth your reading if you have any interest in evolutionary theory. It was Johanson you may recall who was the discoverer of one of the so called "missing links" in human evolution, the skeleton called "Lucy". These old bones, thought to be about 4 million years old, and now known as Australopithecus Afarensis, represent a person that is now thought to be the earliest known link in the evolution of man after separating from the apes. The information we have about these old bones is changing rapidly with new discoveries.
I was particularly struck by the last chapter of the book which has the intriguing title "Is There Danger In Being Too Smart?". What follows is a summary of some of the ideas and conclusions in that chapter. At the risk of changing some of their ideas, this is my own synthesis of the chapter with a few quotations thrown because they say it better than I could.
"The human brain is a truly extraordinary instrument. It allows a living creature, for the first time in the history of life, to contemplate itself (herself/himself ), to gain some knowledge of our origins, of the planet on which we live, and of the universe of which our planet is a part. All earlier life has been utterly ignorant of these things. The human brain does more; it allows us to alter our environment for our own benefit in ways no other creature has ever done--indeed it gives us awesome power to do that."
The general theme of the chapter is the thesis question, "can this oversized brain of ours carry a hidden danger?" In terms of evolutionary thought, is being smart an overspecialization which will ultimately drive us to extinction? Or will something else. Extinction is a part of life. Of all the species that have ever lived on the earth, more than 99% are gone. Two million years from now most of the species that now exist, will be gone. Will humans still be here, barring some catastrophe? We could be. After all, the dinosaurs populated the earth for over 160 million years. However, recent research has shown that mass extinctions do take place once in a while and seem to take place at fairly regular intervals. One can envision natural mechanisms for extinction such as extreme volcanism that cruds up the atmosphere shutting out the sunlight. Or an outside force such as a large meteor impact or comet, such as has just been speculated about in the media, or the earth passing through a very dusty part of the galaxy. Small extinctions take place regularly; mass extinctions only once in a great while.
But what of overspecialization? Edey and Johanson discuss what this means in terms of two examples of specialization. One, the case of the "English Sparrow" (not really a sparrow at all) which was brought to the United States in 1853 in an effort to get rid of the canker worms which were eating away the forests. These birds, fast breeders, chose not to eat many of the canker worms, instead finding it easier to eat food supplied them by humans. They ate seeds. As long as planting and farm animals were prevalent the sparrow population exploded. They quickly drove out native species of bird some of which never recovered. By the end of the 19th century it was the most numerous species in the country. Why was it so successful? The main reason was that it was extremely adaptable. It could live anywhere and eat anything humans ate. It was a generalist in terms of evolutionary parlance. We humans are its specialization.
Edey and Johanson compare the English Sparrow to the Kurtland Warbler, a specialist whose habitat was areas of burned out forests in one small section of Michigan. They only breed among the low scrub pines which took the place of the former forests and have found themselves in a more and more crowded habitat. There was no way of predicting that its habitat would become disastrously small. Today there are only a few of them left. If its habitat disappears, so will this warbler. Many extinctions have taken place in recorded history and are happening even as we speak today.
If the aim of life is to perpetuate ourselves, why would these birds allow themselves to be crowded into as small a habitat. Why was one of these birds so successful and the other so unsuccessful? In truth, neither the Kurtland Warbler or the English Sparrow had any say in the matter. Each was following a path provided to them by accident. The accident is the place you find yourself, quite by chance. If its habitat is too small or if it shrinks for reasons beyond your control, the species may be doomed to extinction.
Edey and Johanson give many other examples but more interesting to me, are their thoughts on the future of humans. So, let's ask their question again: "Can an oversized brain carry a hidden danger? Is it an overspecialization?" Most of us would quickly say certainly not. Our ability to think allows us to be physically unspecialized. We are the best of all generalists. We live anywhere, can provide for our own warmth and food. We can defend ourselves. We don't need to be strong even though many animals see better than we do and we cannot run as fast as many other animals. But using our wits we can out perform all other animals in every way.
But, Edey and Johanson point out, our culture provided by our oversized brain, is outperforming (evolving faster than) its inventor. Physically we have not changed in the last twenty thousand years. It took us half a million years to progress from the use of fire to achieve the ability to grow and produce our own food. Another ten thousand to figure out how to get metals from the ground to make tools. Two thousand more to learn to read and write, another thousand to develop explosives, a few hundred to perfect the internal combustion engine, a hundred to harness electricity, a generation to harness the atom and a decade to invent computers small enough to hold in your hand and do millions of calculations in a minute. We have learned where we came from and how we came into being and why we die. Now we are almost capable of redesigning ourselves. We may be able to redesign our emotional profiles. We pose ethical questions about how to use this ability we are developing but we are progressing so fast culturally that we may progress technologically further than our ability to manage that technology.
We are in danger of damaging our habitat beyond our ability to stop our own extinction. This has been going on for a few thousand years but we are only just recognizing that fact. Recent studies* have indicated, for instance, that children exposed to high pesticide levels before birth, i.e. in the womb, have lower IQ's than those children with the lowest pesticide levels. Green areas are disappearing, air and water pollution is increasing, nuclear wastes are increasing at alarming rates, and the human population is increasing exponentially. Traces of prescription drugs are beginning to show up in public water supplies. We are using our sources of energy at a rate which will make oil pumped from the ground almost obsolete within the next 50 years. Is there a way out of our sure demise? I suspect we will figure out how to keep ourselves warm but I'm not sure.
Edey and Johanson's solution to this is that we will have to get ourselves out of this mess by applied genetics. That is we should make better people by using our technology to accomplish genetic change. If we do this we will need a new definition of evolution, one defined not by chance but by choice.
There is no doubt in my mind that the very basis of our problems lies in over population of the planet which puts tremendous stress on our habitat. Every other problem is a direct result of this overpopulation. We cannot control, to any great degree, when we die, but we can control when we are born. At some point in time, probably sooner than later, such stress will be applied to our system that it will react in some drastic way so as to relieve the stress (Le Ch atelier's Principle.) The results may be catastrophic for us as a species. Our brain is our only advantage, our specialization. Using it wisely is our only hope for prolonging our inevitable extinction.
*Liz Szabo,USA Today.
Your comments are welcome. Tom Furtsch
Last updated: 04/23/2011