This is SCIENCE IN THE NEWS in VOA Special
English. I'm Bob Doughty.
I'm Doug Johnson. November twenty-fourth
marked the one hundred fiftieth anniversary of one of the most influential
books ever written. Naturalist Charles
Darwin published "On the Origin of Species" in eighteen fifty-nine. The book was an immediate success in the
scientific community. Today, evolution
forms the basis for the modern science of biology.
Evolution can be defined
as change in groups of living things over time. Small changes take place in each generation of organisms. Those with useful changes survive to
reproduce. Changes that do not aid
survival disappear. This is the idea of
natural selection. Over long periods of
time, these small changes result in the creation of new species. They are the reason for the many different kinds
of life on Earth.
idea that species change was not new even in Darwin's time. The idea dates back to ancient Greece. In the late eighteenth century, Darwin's
grandfather, Erasmus Darwin, suggested that species evolved from their
ancestors. He even thought that competition
helped drive change.
At the beginning of the nineteenth century,
Jean-Baptiste Lamark attempted a fuller explanation. He suggested that individual organisms
changed in reaction to their environment and passed on these traits to the next
had been working on his theory for over twenty years when he published "On the
Origin of Species." Yet it was the work
of naturalist Alfred Russel Wallace that
pushed Darwin to finally release his theory. Wallace had studied plants and animals in South America and the South
Pacific. In eighteen fifty-eight, he
sent Darwin a short study he had written containing ideas about evolution. Darwin was shocked by its similarity to his
In July of that
year, Darwin's friends Charles Lyell and Joseph Hooker had studies by both men presented
to the scientific group called the Linnean Society of London. But the first explanation of evolution in
public caused little reaction.
year later, Darwin would complete his detailed study of evolution through
natural selection. With its publication,
Darwin gained important supporters like Thomas Huxley who were willing to
defend his ideas.
did not explain everything about how species evolved. It is important to remember that many of the greatest
biological discoveries had yet to be made when Darwin published "On the Origin
WARREN SCHMAUS: "When Darwin first proposed his theory
in eighteen fifty-nine, he had no concept of a gene, no concept of a chromosome,
no concept of mutation, and certainly no concept of things like DNA and RNA."
Warren Schmaus of the Illinois Institute of Technology says the union
of evolution and genetics only started around the nineteen thirties. Also, in Darwin's time, the age of the Earth
was estimated only in the millions of years—too short a time some said for
evolution to work. Not until the
nineteen fifties did scientists, using radioactive dating, place the age of the
Earth at over four billion years.
natural selection has stood the test of time as a basis for the science of
biology. Professor Schmaus notes that,
before Darwin, naturalists only collected and named species.
WARREN SCHMAUS: "I mean it's hard to even understand
how biology was a science as we would recognize it today. I mean, where are the scientific explanations
celebrate Darwin and his idea, the Smithsonian Institution's National Museum of
Natural History in Washington created a special exhibit. "Since Darwin: The Evolution of Evolution"
opened in September. It uses objects
from the museum's collection to show how Darwin helped us understand the
history of life on Earth. The goal is to
show that evolution is not an old, accepted idea, but continues to be the basis
for new discoveries, itself changing with modern science.
People from all over the world have
visited the exhibit. Many people found
the objects and displays helped explain a subject that is hard to understand.
Irene Mikkelson were visiting Washington from Charlotte, North Carolina when
they stopped by the museum. Mister Mikkelson
called the exhibit educational.
JIM MIKKELSON: "I never really realized that that meant
that every living thing really came as an evolutionary development of the first
seeds of life."
lives in both India and the United States. She brought her daughter Khiyali to the exhibit and was
surprised to find how much she already knew.
ARAVINDA PILLALAMARRI: "What I find interesting is how
much of evolution she really takes for granted. For her the idea that birds have come from dinosaurs is just common
knowledge and there's nothing surprising in that at all."
Leonard attends George Mason University in northern Virginia. He visited the exhibit to research Darwin's
KEITH LEONARD: "It's based on scientific observation
which I think is important. And sort of
the same ideas have been confirmed over and over again. I think trying to understand our world is a really
complicated endeavor and it's important to have a sort of solid rational
approach like science does."
visitors spent a long time looking at the display called "The Tree of Life." Darwin explained the evolutionary process as
the branching of a tree with complex species developing from simpler ones.
John Kress, a botanist and curator with the
Smithsonian, says the team that created the exhibit had a different idea. He says the display was designed to look like
a map of the local Washington Metro train system instead of a tree. The reason? All life is connected. Now we
know that genetics makes this connection even deeper and we are linked to our
ancestors by DNA.
is a theory, a word that is often used to describe an educated guess. But it is a scientific theory based on
repeated observations, experiments, measurements and discoveries. A scientific theory represents the best
explanation of how the natural world works.
There is almost no disagreement over the main ideas of evolution
in the scientific community. But the
idea that species have evolved from simpler forms is less accepted by the public. A Gallup Poll opinion study taken last
February found that twenty-five percent of Americans reject evolution. Thirty-nine percent accept it and the rest
have no opinion.
Many important American court cases have
dealt with evolution. The most famous
took place in Tennessee in nineteen twenty-five. The trial found high school teacher John
Scopes guilty of violating a state law banning the teaching of evolution. Later cases ruled that teaching religious
creation stories in public schools violates the First Amendment of the
Constitution that calls for separation of church and state.
recently, religious groups have supported the idea of intelligent design in
public schools. This is the idea that an
intelligent force created all forms of life. In two thousand five, a group of high school students brought legal
action against a Pennsylvania school district. Dover area schools had required that intelligent design be taught along
with evolution. A United States District
Court said intelligent design was not science and could not be separated from
there have also been efforts to bridge the differences between religious belief
and evolutionary science in recent years. Francis Collins, the director of the National Institutes of Health in
Bethesda, Maryland, has attempted to do that. He is a geneticist who led the effort to map all the human genetic
Francis Collins started
an organization called the BioLogos Foundation. It is meant to support the idea that traditional Christian beliefs can
coexist with science and evolution. In
two thousand six, his book, "The Language of God: A Scientist Presents Evidence
for Belief," became a national best-seller.
hundred fifty years after "On the Origin of Species" first appeared, it remains
one of the most influential and debated books ever written. But it is only a beginning. John Kress of the Smithsonian says that,
while science accepts evolution, debate continues.
JOHN KRESS: "We do have debates among ourselves over
the exact process. And I think this is
what science is about. We continually
test our ideas; we continually conduct experiments to see if we can gain new
insights into how life evolved and that's what really science is all about."
SCIENCE IN THE NEWS was written and produced by Mario Ritter. I'm Bob Doughty.
And I'm Doug Johnson. Visit our Web site at voaspecialenglish.com
to find a link to the works of Charles Darwin. And join us again next week for more news about science in Special
English on the Voice of America.