THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Monday, March 27, 1995 TAG: 9503270038
SECTION: LOCAL PAGE: B3 EDITION: FINAL
TYPE: Interview
LENGTH: Long : 149 lines
With five years left in the 20th century, human beings are causing global climate changes mimicking those that led to massive planetary extinctions millions of years ago.
It's not just the plants and animals around us that are threatened by our greed and our sloppiness. We're in danger of killing ourselves unless we change our behavior.
So asserts Niles Eldredge, co-founder of an evolutionary theory that takes issue with the standard model developed by British naturalist Charles Darwin nearly 140 years ago.
Eldredge, a curator with the American Museum of Natural History in New York and an adjunct faculty member at Columbia University and the City University of New York, will speak in Norfolk on Tuesday about the future of the planet and of the human race that populates it.
Staff science reporter James Schultz recently spoke with Eldredge by phone at the curator's suburban New Jersey home.
Q. Evolution is often described as a ``theory.'' But most scientists refer to the ``facts'' of evolution. So is evolution theory or fact?
A. There's a thin line between fact and theory. People think of theories as wild, crazy or hare-brained ideas. The word theory means a well-thought-out and highly correlated system of thought in science.
The theory of evolution is that all life has descended from a common ancestor. A fact is nothing but an idea that has been so well-established that nobody disputes any aspect of it.
(Evolution) is such a well-contrived theory that there's no doubt in my mind that life has evolved. The only thing that ties bacteria to humans is the notion that everything is linked together by this general process we call evolution.
Q. Some say that religious belief and acceptance of evolutionary theory are mutually incompatible. What do you think?
A. Ever since (Charles) Darwin wrote the ``Origin of Species'' (in 1859), there's been this big firestorm and series of debates.
The mainstream Protestant sects, the Catholic Church and lines of Jewish thought hold that God created Heaven and Earth using natural laws. That's not antithetical to religious belief. It's only when you insist that God takes personal responsibility for every living thing that you start getting into real difficulty.
I was raised in a religious background myself. Being a scientist doesn't mean you have to be an atheist by any means. I've known lots and lots of scientists who maintain a religious tradition and yet are very fine scientists. There is no necessary conflict between religion and science.
Q. In evolutionary terms, what's happening to the world's plant and animal species?
A. Whole ecosystems are very stable for long periods - unless and until something environmental comes along, kicks the systems and turns things around.
Two-and-a-half million years ago there was a cooling pulse, a cold snap on a global basis, when temperatures dropped 10 to 15 degrees Celsius (18 to 27 degrees Fahrenheit). That's a lot. That's very cold. It had a profound effect on African woodlands. It turned them into savannas. That made the place uninhabitable for species unable to adapt and evolve.
Nothing like that is happening right now. However, I think we're entering the sixth major global extinction because of our habitat destruction. There's almost 6 billion of us, and because of agriculture, we're transforming the landscape and the physical surroundings. We're beginning to mimic the effects of natural climate.
This will have a long-term effect. I just hope we're around to see it.
Q. Are we in imminent danger of losing species diversity?
A. We're in the early stages.
Some species in the tropics are used to a narrow temperature range and can't adapt to much change. They have no place to go, no place to hide. One estimate is that we're losing three species per hour there right now, 27,000 species per year. We really don't know for sure.
Even though in North America numbers of species are down, there are relatively few species that have been driven to extinction. We have fewer species (here), but they occur in greater numbers, spread over a larger area. They're much more broadly adapted because over the seasons there's a huge temperature variation.
Q. Why is diversity important?
A. That's the 60-dollar question. The answer I always give and I'll give at Old Dominion: It's an illusion that we're outside nature.
We depend on the planetary ecosystem for oxygen to breathe, for the nitrogen in our bodies. We are, in a fundamental way, tied in with all living things. We can't go around anymore and trash ecosystems and then move on. We've reached a threshold.
Diversity matters because Nature is an incredible chemical library. Even though we can make all sorts of things in our labs, there are many natural substances we can't, we haven't dreamed up. Our future has very much to do with the health of the planet.
Q. Mass die-offs have happened before. Doesn't extinction make room for other plants and animals?
A. Yeah. It does. But the real catch here is that we're part of the system. Our natural reaction ought to be conservative and fight to maintain the system we're part of. We're here now and we might not be here to enjoy future evolution.
The health of the global ecosystem is the summation of the health of local systems. . . . Disease, famine and warfare could spread. It would be tough to kill 6 billion people - but it's possible.
Q. What can human beings do to slow or stop these mass extinctions?
A. First of all, we've got to control population growth. The other thing we can do is look at our effects on natural systems. It's realizing that sustainable development and the economic lives of people have to be addressed.
The whole notion of sustainable development talks about the wise use of resources. It's not a fortress mentality. It's letting local people utilize aspects of their ecosystems so they become conservationists themselves. They become enlisted as guardians rather than destroyers. It's an ethic formulated in economic terms.
Q. In 1972 you and Stephen Jay Gould coined the term ``punctuated equilibrium.'' Why that phrase? And how does it compare to the standard ideas put forth by Charles Darwin, founder of evolutionary theory?
A. The fossil record shows that once species appear, they change not very much in 5 or 10 million years. The standard picture coming from Darwin is that the evolutionary process inevitably keeps changing species. Species do evolve and natural selection accounts for anatomical change within species. It's just that they don't keep evolving over millions and millions of years.
Punctuated equilibrium is a two-word phrase for this great stability punctuated at odd intervals by relatively rapid bursts of evolutionary change. The punctuated part is when new species appear, they tend to appear rapidly. Over 5,000 to 10,000 years you get this rapid drive toward evolutionary change, and things settle down again for 5 to 10 million years.
Q. What will humans have become 1 or 2 million years from now?
A. If we survive for 2 million years, we will look very much as we do right now. Growing bigger heads and skinny bodies like E.T. - that's not going to happen. Cultural evolution has replaced natural evolution.
We're using technology to approach the basic problems of living: food, shelter, disease. Right now we're in a crescendo of inventiveness. And it's snowballing. The critical thing is to learn from one another. That bypasses the much slower evolutionary and genetic transmission of information.
Just consider the difference between the world right now and the world my grandparents were born in.
There's been an astonishing change, and just over one century.
Q. You sound like an optimist.
A. I would like to be one. I really do feel that we've used our cleverness to get this far.
If we just face the reality, maybe we can do something about this crisis we're facing: eating ourselves out of house and home and fouling our nest. ILLUSTRATION: ADRIANA LIBREROS
Staff illustration
Niles Eldredge will present his talk at Old Dominion University's
Mills Godwin Auditorium at 8 p.m. Tuesday. His presentation, ``The
Miner's Canary: Unraveling the Mysteries of Extinction,'' is free
and open to the public.
by CNB