http://www.nationalgeographic.com/

WAS DARWIN WRONG?

In its November cover story, National Geographic deftly answers the provocative question that has fiercely divided schools, churches and courthouses from Kansas to Michigan, Tennessee to Washington state, and California to Maine. Was Charles Darwin's theory of evolution by natural selection wrong? As educators, judges and parents decide if (and how) to teach evolution in the classroom and as many people continue to misunderstand and misconstrue Darwin's theory, National Geographic reports that the evidence in favor of evolution is overwhelming. In fact, world-renowned science writer David Quammen reveals that the process of evolution is more crucial today to human welfare and to the most urgent biomedical research being done in the study of microbial diseases, such as AIDS, Ebola, SARS, tuberculosis, malaria and West Nile fever.

NEARLY HALF OF AMERICA DOES NOT BELIEVE IN EVOLUTION According to a Gallup poll taken in February 2001, 45 percent of responding U.S. adults believed that evolution has played no role in shaping human beings. What startled Quammen about these poll numbers is not that so many Americans reject evolution but that the statistical breakdown hasn't changed in the past two decades. To draw a finer point, the creationist conviction — that God alone, and not evolution, produced humans — has never drawn less than 44 percent in a Gallup poll. And yet, ironically, the same people who deny the occurrence of evolution live their lives based on the reality of Darwin's theory. This year, many will grow increasingly concerned about being over-prescribed antibiotics by their doctor. They will search out sources for the new and limited flu shot to ward off the most recent strain of virus. They may curse the insecticide they've sprayed on the lawn when it doesn't kill the weeds like it did last year. Each instance is evidence that evolution is happening, yet it would seem that nearly half of America doesn't see — or perhaps refuses to acknowledge — what is taking place around them.

DARWIN'S BIG IDEAS AT ISSUE Some people are tempted to say that Darwin's theory of evolution by natural selection is "just" a theory. But in the same sense, Einstein's theory of relativity is just a theory. National Geographic clarifies what scientists mean when they talk about a theory, stating that a theory is not a dreamy and unreliable speculation, but an explanatory statement that fits the evidence. And believing that no one needs to, and no one should, accept evolution — or any theory — merely as a matter of faith, Quammen succinctly elucidates the big ideas of Darwin's that are at issue: the evolution of all species, as a historical phenomenon, and natural selection. Quammen writes, "The first is a question of what happens. The second is a question of how."

EVOLUTION BY NATURAL SELECTION Many people wrongly summarize Darwin's theory of evolution to mean that we have descended from apes. National Geographic Editor in Chief Bill Allen writes in his Letter from the Editor, "Humans are not descended from apes. But then Charles Darwin never claimed we are." National Geographic's cover story reveals what Darwin actually said, which was that the myriad species inhabiting Earth are a result of repeated branching from common ancestors — a process that came to be called "evolution." The mechanism of evolution, Darwin's "natural selection," determines how plants and animals come to look and behave as they do.

Quammen explains how small, random, heritable differences among individuals result in different chances of survival and reproduction — success for some, death without offspring for others — and that this natural culling leads to significant changes in shape, size, strength, armament, color, biochemistry and behavior among the descendants. He writes of how excess population growth drives the competitive struggle. And how, because less successful competitors produce fewer surviving offspring, useless or negative traits tend to disappear, whereas useful ones are perpetuated and magnified throughout the population.

EVIDENCE OF EVOLUTION TODAY Quammen explains how scientists, by using techniques unheard of in Darwin's time, are finding more evidence than ever of the evolutionary links among all living things. Modern genetics presents much evidence supporting Darwin's theory, including:

-The Mouse Genome Effort, which reveals that of a mouse's 30,000 genes, 99 percent have direct counterparts in humans. Such genetic similarity gives meaning to biomedical research that helps humans by using mice and other animals, including chimpanzees, which are our closest living relatives.

-Disease-causing microbes: The most urgent biomedical research today is the study of microbial diseases, such as AIDS, Ebola, SARS, tuberculosis, malaria and West Nile fever. The capacity for quick change among these microbes is what makes them so dangerous to large numbers of people and so difficult and expensive to treat. They leap from wildlife or domestic animals into humans, adapting to new circumstances as they go. By natural selection they acquire resistance to drugs that should kill them. They evolve.

-Antibiotics are a powerful evolutionary force, driving bacteria to evolve powerful defenses against all but the most recently invented drugs. In 1943, penicillin proved almost miraculously effective in fighting staph infections. Its use marked a new phase in the war between humans and disease microbes, a phase in which humans invented new killer drugs and microbes found new ways to be unkillable. Through the decades, the morphing of drug-resistant strains of staph infections represents an evolutionary series. They make evolution a very practical problem by adding nearly $30 billion a year to the challenge of coping with the infection.

-Insects and weeds acquire resistance to insecticides and herbicides through the same process.

-HIV: After just a few years of infection and drug treatment, each HIV patient carries a unique version of the virus. It's a speeded up and microscopic case of what Darwin saw in the Galapagos — except that the human body is the island.

CAN WE SEE EVOLUTION IN ACTION? National Geographic confronts the familiar argument against evolution, which is that we can't actually see it in action. In fact, evolution can be observed and measured in both the wild and in the laboratory. Quammen highlights scientists who over decades of field study have observed the slow evolutionary change in beak size among Galapagos finches, and also interviews scientists who have achieved evolutionary results in a laboratory with an unsplit lineage of 35 generations of fruit flies.

A TOUR OF DARWIN'S BRAIN: THE THOUGHT PROCESS THAT LED TO THE THEORY In addition to clarifying the central tenets of evolutionary theory, National Geographic takes readers on a journey through Darwin's astonishing research, ruminations and discoveries, which culminated in one of science's seminal theories. To the surprise of many today, Darwin was shy and had many close friends among the clergy. Quammen describes how and why Darwin spent 22 years secretly gathering evidence and pondering arguments — both for and against his theory — before publishing "The Origin of Species," which he raced to finish upon realizing that two decades of work was about to be scooped. Photographer Rob Clark's images allow readers to imagine that they are seeing and thinking like Darwin, with new patterns unfolding before their eyes.

Some of the questions Darwin pondered while forming his theory of evolution and natural selection:

-Why do similar species inhabit neighboring patches of habitat? -Why are similar habitats on different continents occupied by species that are not particularly similar? -Why does the embryo of a mammal pass through stages resembling stages of the embryo of the reptile? -Why is the larval form of a barnacle similar to that of a shrimp? -Why do five-digit hands appear not just in humans, apes, raccoons and bears, but also in cats, bats, porpoises, lizards and turtles? -Why do some snakes have the rudiments of a pelvis and tiny legs buried inside their sleek profiles? -Why do remote islands contain such diversity?

For over 20 years, Darwin pondered these kinds of questions, conducted experiments around them, and meticulously recorded his observations in a remarkable effort to form a theory that would consistently account for each of them. For Quammen and National Geographic, what he found you can take to the bank.

DOES EVOLUTION EXCLUDE GOD? As Editor in Chief Bill Allen states in his Letter from the Editor, "National Geographic aims to explore the world, often by highlighting scientific concepts such as evolution. Is this approach necessarily at odds with faith, which lies beyond the possibility of scientific proof? No. Just as religion did not disappear after Galileo demonstrated that the Earth is not at the center of the solar system, evolution does not exclude God from our origins, the 'mystery of mysteries' — a 19th-century astronomer's description borrowed by Darwin himself."

http://www.nationalgeographic.com/

###

###

Contacts: Laura Moreland National Geographic Society (202) 857-7001 lmorelan@ngs.org

Caryn Davidson National Geographic Society (212) 790-9032 cdavidso@ngs.org

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-NEWS is a service of the Metanxus Institute <http://www.metanexus.net>. NEWS is a free opt-on only email distribution list which publicizes and promotes events, publications, and opportunities related to the academic dialogue between science and religion. NEWS text may be quoted or republished with appropriate attribution to the source of the postings and the Metanexus Institute. The views and events posted do not necessarily reflect those of Metanexus or its sponsors. Metanexus reserves the right not to publish unsolicited postings without comment. To subscribe to this or other distribution lists, including our bi-weekly DIGEST edition, go to http://www.metanexus.net. Please send all inquires and submissions to <editor@metanexus.net>. Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 by William Grassie.

Published   2004.11.18