You and I started out as one complete cell, as did most plants and animals. That one cell produced other cells that carried on different functions. Scientists are still not sure exactly how the DNA of a cell works, but they have found out enough so that we can understand much of how evolution works.
As an example, suppose there is a cell which has the capacity to produce a hard substance. Let's suppose that that substance becomes specialized and serves as a claw. This is good, and there may be many kinds of claws serving slightly different functions. Some may be used to kill, or to climb, or to scratch, or even to dig. But if there is a change in the DNA, and the cell produces something very different it may lead to something that better suits another creatures survival. The claw could become a finger nail and aid in dexterity, or a hoof and aid in running. The cells that produce fingernails, claws, and hooves are all basically the same.
In this same way, cells that produce scales, feathers, and hair are the same. The cells that at one time only produced scales changed and some gained the ability to produce feathers. This change was necessary in order to have birds evolve. Some changed and produced hair. This change was necessary in order to have mammals evolve.
During the evolutionary process, some DNA within some cells have changed a great deal while others have changed very little. There seems to be a big difference between a tooth and a tusk or fang, but the way they are formed by cells is much the same. The difference between a hair and a feather is dramatic even though the way they are formed is much the same.
Keep in mind that most of the chemical changes in DNA (mutations) would be harmful and would not aid in the survival of the plant or animal; the change would not be passed on to future generations. In a few instances, however, these changes would aid in the survival of individuals who could then pass the better characteristics on to future generations.
This is what evolution is all about. That is, random changes in DNA and natural selection by the survivors of that change.
This explains why not every species evolved into something else. Not all animals that have cells that produce scales had a mutation in DNA in order to begin to produce feathers and hair. Only a few did. They then were in competition with the creatures who still had scales.
Survival means a struggle for space and food. The animals that had control of the space and food usually had some survivors, even though the new feathered and hairy creatures were becoming better suited to the environment by evolving lots of types of feathers and many kinds of fur.
This should make you wonder about other substances that cells produce.
The cells that produce the bones in a mouse are the same as the cells that produce bones in an elephant. They have the same bones. So why the big difference in size? The answer is that other cells are producing chemicals that effect how much bone gets produced. Producing a lot results in a big animal, producing a little results in a little animal.
These chemicals are hormones and they are as important in evolution as physical features. Behavior must be passed from one generation to another. It is obvious to us that a ducks bill and the beak of a woodpecker must be programed for different uses. The bones of the forelimb of a frog, a turtle, a bird, a whale, a bat, a horse, and a human are fundamentally the same. Hormones are necessary to guide the animal to use their limbs properly.
Hormones not only direct growth, but also fear, sexual behavior, and much of what we call life functions.
Any useful chemical produced by cells is called a secretion. Some secretions become teeth, some become ear wax, some become hair, some help determine behavior, and some aid in digestion and all the other vital chemical reactions that support life.
February 12, 1809, is the birth date of Charles Darwin. He changed scientific thought forever. First with his evidence on evolution and then with his ability to write so that everyone could understand his scientific books.
The Origin of Species was not the first book on evolution. The idea goes back to antiquity, and among nineteenth century authors the evolutionary notions of others had been widely discussed since the early 1800's. What Darwin actually accomplished for evolution was to make it more than just speculation. He was the first to discover the compelling evidence for evolution, and to show how evolutionary thinking could be used as the basis for scientific investigation. He also provided a plausible cause, or mechanism, for evolution. This was his principle of "natural selection," which he explained by analogy with selective breeding in agriculture. The breeder selects the kind of animal or plant he wants from a varying group of organisms (artificial selection), subsequent generations become more and more like the kind he chooses. Darwin proposed that something very much like that occurs in nature, and therefore called it "natural selection."
Most scientists believe that Darwin's greatest contribution to understanding our world is the theory of natural selection. As a result of this theory, scientists were able to leave the outdated explanations that they had been dealing with for so long and enter the realm of answering why certain phenomena occur. In other words, they had a testable method of proving where certain traits appeared, and why they were successful.
Prior to 1859, when the On Origin of Species became a topic of conversation, scientists were forced to answer questions with the same types of explanations that are sometimes still used today: intelligent design, abrupt appearance, or created by God.
With the natural selection theory, they were finally able to show a route by which certain phenomena were reached while others were rejected. Suddenly, reasons for why many things occur became understandable.
Natural selection gave us a method of understanding why all biological phenomena arise.
The Darwin revolution has grown steadily since 1859, and has resulted in a theory that is more easily explained scientifically, predictive, socially significant, and also more easily applied than any previous model has been in the history of science. And yet, with all of these changes, the real work for Darwin's theory was yet to come.
The study of genetics, discovering DNA, advances in biochemistry, and amazing technical advancements, such as the computer have all added strength to the theory. So much so, that it is considered by most scientists to be a scientific law.
Modern scientists (William Hamilton of Oxford, Richard Dawkins of Oxford, Stephen J. Gould of Harvard, and others) began using a gene-focused and kin-selected variant of natural selection that Darwin could have never dreamed about. Darwin's ideas were sharpened to such an extent that there are few phenomena that it does not seem to readily explain.
It is the application of "survival of the fittest" to genes rather than individuals which gives natural selection the scientific authority it truly needs.
Charles Darwin died at the age of seventy-three, and the world has not been the same since.
Evolutionary thinking has a long and interesting past. There have always been people who did not accept the biblical account of creation, or the myth of Noah's ark and the world-wide flood. Most did not make their views known publicly due to of fear of imprisonment or death.
Over five hundred years ago, Leonardo da Vinci wondered how fine, delicate seashells could survive intact from the ocean to the high mountains of Italy. He also wondered about these shells being in layers as if there had been more than one flood.
Time passed, and more and more physical evidence began to be discovered. Three hundred years ago, fossilized bones, plants, footprints, and shells had been found in great numbers; but this evidence was still being interpreted in the western world from the traditional biblical view.
In the middle 1700's, two French biologists, Buffon and Lamarck, were sure that evolution took place, but they had the wrong idea as to how it came about.
In England, Charles Lyell and other geologists were convinced that different plants and animals lived at different times, because of extinct fossils found in different layers of rock.
So it was not unusual that in the mid 1800's, a mere 150 years ago, the biblical view began to be challenged. This was the result of other things that were going on at the time. People were mining, building canals, digging quarries, trading in distant lands, and breeding different varieties of plants and animals (artificial selection). The evidence to support a more scientific way of understanding the history of our planet and living things was a natural result of accumulated evidence.
Charles Darwin and Alfred Wallace presented their views on evolution to the Linnaean Society in 1858. They were not the first to suggest a changing world of plant and animal life, but they were the first to argue that natural selection is the mechanism for evolution.
Alfred Wallace had done his work in the East Indies using mostly insects. Tragically, a fire aboard ship destroyed most of his specimens and evidence. Darwin had most of his collected materials and evidence stored in museums. That placed Darwin in the position of being the main defender of the new theory of evolution. How fortunate we are that Charles Darwin collected so many specimens, and wrote so many books.
Darwin, of course, was never able to answer some of his critics because they were asking questions that at the time had no answers. But science is not a static thing, and with new techniques and much more evidence, all but a few have been convinced that life on this planet evolved. Every major university in the world accepts evolution as fact.
Much of the early investigation of evolution was based on fossils and the geologic record, artificial breeding, and structures of plants and animals. All of these have advanced greatly in the last 150 years and the evidence for the evolution of different species does come from these sources, but now we can also include radioactive dating, comparative biochemistry, comparative embryology, and genetics.
Those who do not accept the evidence for the theory of evolution are still using old worn-out arguments, so it is important to review the established evidence from time to time and also to explore the new evidence.
"The Phrase 'survival of the fittest,' often used in discussions of evolution, suggests that the important outcome of natural selection is survival; it is not. Rather it is contribution of genes to future generations." From Biology, by Arms and Camp, 1995. Page 368.
In 1831, Charles Darwin started a five year voyage around the world on the HMS Beagle. This experience gave him the insight that isolation can lead to different species. When he compared the life on continents with isolated islands, he found that some species were very different. Isolation, time, and reproduction had a telling effect on the evolution of isolated species.
Today we have the advantage of advanced scientific methods to help us understand the importance of biogeography. The science of plate tectonics proves that continents once were connected and that they have drifted apart. They are still moving, and the rate can be measured.
Studying the distribution of plants and animals allows scientists to draw evolutionary conclusions. This information can offer explanations as to the center of origin of each species.
The advantage that scientists have today that Darwin did not have is an understanding of genetics and the genes in a species population, known as the gene pool. When a species and its gene pool becomes isolated, it can follow its own evolutionary course.
Many factors can isolate a population. It may be a mountain range, highlands and lowlands, lakes, and especially the ability of the organism to move.
The earth evolves, and in order for living things to survive they must also evolve to keep up with the changes.
Geography offers barriers that allow species to evolve separately, but there are other barriers that can cause isolation. There are reproductive barriers that prevent populations that belong to closely related species from interbreeding even when their ranges overlap.
Mating may take place at two different times. This can be at different times of the year, or even different times of the day. As an example, some owls do their mating in the winter; others in summer. Some mosquitoes are early morning breeders, while others are late afternoon breeders.
There can be behavioral isolation where there is no sexual attraction between males and females of different species. As an example, fireflies mate by using signals and they only respond to the pattern of their own species.
Mechanical isolation occurs when the structure of reproductive parts are not compatible. In fleas, the reproductive organs are like a lock and key. Each female of a species has her own lock (vagina) and only the key (penis) of her species will fit.
There is also genetic isolation. That is, when it is chemically impossible for sperm and egg to unite. The value of this can be easily seen when we realize how many different types of pollen grains are in the air and are likely to land on a flower of a different species.
Charles Darwin realized that evolution was not a process which was destined to lead to higher forms of life. He referred to evolution as buds on a branch, each bud with the capacity to be different. Each living thing that evolves and survives to reproduce is adapting to a specific niche. It is not evolving to become a higher form of life. Some adaptations are so specific that the organism actually decreases its chance of survival if a slight change takes place in its environment.
The fossil record has many examples to show that this is true. It shows very clearly that evolution is not a direct line in any direction, but has thousands of directions. Some survive, others do not. In other words, there is no intelligent design.
Almost all the evidence to support evolution comes from sources other than fossils. Less than 15% of Charles Darwin's work involved fossils. The reason is that very few fossils retain their original organic matter. Usually when an organism dies, the decomposers and scavengers quickly devour it. Rarely is something left behind to show evidence of life long past. A bone may be replaced with minerals, a footprint or leaf print, an insect caught in amber, chemical remains (oil), and even preserved excrement are all fossils.
One of the main reasons that fossil evidence proves evolution is that predictions can be made and verified. That does not mean a prediction of the future, but a prediction that another scientific discipline will be able to verify some already discovered evidence. Any theory that is established in science to the point that it becomes a scientific law must be able to be counted on to be reliable. Think of all the scientific principles that we predict will happen when we drive a car, fly a plane, take a medicine, or put on glasses. These things work because science works. Science works because with most sciences we can predict what will happen in nature very accurately.
There are many examples of evolutionary predictions about fossils that were later proven to be correct. Three examples are whales, elephants, and gill slits.
It was predicated that fossil evidence would be found that would show the transitional forms between land mammals and the marine mammals. At least three new fossil forms of whales have been found to show a connection between the modern whale and their land dwelling ancestors. In the process, scientists have learned much about adaptation of the skeletal structure for life in the ocean.
Secondly, elephant embryological evidence shows development of four tusks - two upper, two lower. The two lower degenerate and do not develop. This led scientists to predict that some day fossil remains would be found of elephant ancestors with four tusks; they were also found.
Some fossil sharks have seven gill slits and some have five. It was predicated that fossil sharks would be found in transition with six gill arches; they were found also.
There are a number of predications that have been made concerning extinct plants as well as animals, but the important point to remember is that there is no reliable explanation, other than evolution, to explain fossils.
"There are thousands of 'missing link' fossils, and every year more are found. Examples are the stages between reptiles and mammals, between reptiles and birds, between land mammals and whales, between horses and their progenitors, and between humans and their extinct ape-like ancestors. The so-called fossil 'gaps' are partly due to the rarity of conditions for fossilization and to the relatively rapid series of mutations emphasized by Gould and his associates." From Notes of a Fringe-Watcher, Skeptical Inquirer, November\December, 1997.
Comparing the structure of living things is one of the oldest methods to show that evolution has taken place. Of course, now that the structure of DNA and biochemical analysis has come into use, these much more detailed and accurate methods shed more light on how and when evolution occurred. Even so, comparative morphology is still one of the strongest sources of evidence in support of evolution.
The bones in the skull of a human, a monkey, a bird, or even a fish are basically the same. They have evolved different shapes to accommodate the differences in brain shapes.
It was obvious to the people long before Charles Darwin's time that the bones in human arms and legs were basically the same as other vertebrate animals. The leg of a chicken has the same bones we have. One upper leg bone (the femur), two lower leg bones (the tibia and fibula), long foot bones (metatarsals), and toe bones (phalanges). The chicken and many other animals look different to us because they walk on their toes and not on their metatarsals.
These animals also have the same brain parts; a cerebrum, a cerebellum, an optic lobe, etc.
The glands that are found in a human are also found in all the other vertebrates and serve almost the same functions. The pituitary glands, the adrenal, the thyroid, and all the other glands show that these animals have a common ancestor.
The reason cats are dissected in anatomy classes in college is because they have the same muscles and other organs that humans have. When we eat frog legs the muscles we eat have the same name and location as the muscles in our legs because they came from the same primitive tissue. The same can be said about chicken wings
We commonly think of animals when we discuss evolution, but we must not forget that plants also have their evolutionary history. The evolution of the structure of flowers, roots, stems, and leaves can also be traced. In some cases, the history of plants is even easier to trace because many plant fossils are better preserved and intact.
What all of this means is that we can trace plants and animals back to original ancestors. We can show that fish, birds, amphibians, reptiles, and mammals have a common ancestor. We can also show that oak trees, carrots, and moss have a common ancestor.
The world of insects is one of the easiest places to show evolutionary development. When Alfred Wallace, along with Charles Darwin, presented the first scientific paper on the Theory of Evolution he used insects and their structure to illustrate his findings.
Long before the time of Charles Darwin many people realized that species changed into other species, but there was not enough scientific evidence to support this belief. At that time it was called transmutation.
Thomas Malthus had written a book stating that human populations could outgrow food supplies. Darwin thought that this might apply to all forms of life. When Darwin studied the works of geologist Charles Lyell and found that the earth was millions of years old, he realized there was time for small changes to result in whole new species.
He reasoned that because the earth was changing, life must also change, and that nature provides the environment that causes certain variations to survive.
Darwin knew nothing about genetics, but he had observed that humans provided artificial selection in agriculture and animal breeding. This along with fossil evidence, the study of anatomy, geology, and geographic distribution showed evolution was taking place.
What natural selection means is that there is over production in all species, that there is a struggle for food and space between species, and members of the same species, and there is competition for mating. The best suited survive and reproduce.
Soon after the invention of good microscopes, scientists began to trace the development from embryo to adult to see where each tissue came from.
It was obvious that the four buds that formed on the vertebrate embryos were going to develop into fins, wings, or limbs. We could also see that an elephant's trunk and a dog's nose came from the same tissue, or that the tissue in every animal that makes an ovary also may turn out to be a testicle given the right hormones. In the beginning of any animal's development, it is difficult to see what it is going to become. Later on in embryo development, things happen that anyone can see without the aid of a microscope.
It is now possible with many animals to trace back to the very cells that produced the organs that adults have. When the egg and sperm unite to form a complete cell, the zygote, it begins to divide: two, four, eight, sixteen, thirty-two, sixty-four, etc. Soon some of these cells, because of their location on the zygote, will become different from others. They are about to form an embryo with different tissues.
The cells that produce the tissues that become organs are referred to as stem cells. Stem cells in a turtle, a bird, or a bat that produce, as an example, the liver, come from the same place. The adult liver is slightly different in each animal because the egg and sperm that created them were slightly different. The reason that medical science is so interested in stem cells is that they have the ability to become tissues that may help in the cure of an illness or deformity.
What this shows is that animals all have the same ancestor. They are all related to some creature in the past that evolved into many different forms. Most of these forms died out and became extinct, but a few survived to become the life we are familiar with on this planet Earth.
The same can be said about plants. They have stem cell too. The stem cells that produce the leaf of an orange tree are the same that produce a leaf of a corn plant. The difference is caused by the difference in the sperm and egg that united to produce the plant embryo (remember that pollen produces sperm). This shows that the orange tree and the corn plant are related by some distant ancestor.
When embryo development of different plants or animals are compared, it is quite easy to see that they go through roughly the same stages. The journey from fertilized egg to adult is almost the same in all living things.
All of the studies in astronomy show that the Universe is evolving. All of the studies in geology show that the Earth is evolving. What we sometimes forget is that these processes have a great effect on the evolution of living things.
It is obvious that the sun and moon have had an effect on the evolution of life on Earth. It may be more difficult to understand the effects of the changing Earth on evolution of living things.
We do not feel the continents move, a process called plate tectonics, but it happens. We do not see huge meteorites collide with the Earth, but it has happened. We do not feel the mountains rise, but it happens. All of these things can be measured by using scientific instruments. Add to that weather changes, volcanoes, hurricanes, and lightning, and a very hostile environment is seen.
The only possible way that living things can possibly survive the physical changes that have occurred on the planet for billions of years is to evolve and adjust to these changes.
As an example, let's look at the creatures that live in the oceans. At one time in eons past, the oceans had no minerals in them. The minerals that make the oceans salty came from rivers that washed minerals from land into the sea. These minerals made the ocean an extremely hostile environment, a deadly and impossible place to live because such a high concentration of minerals will kill cells. So why is the ocean teaming with life? It is because the change in the ocean water took place so slowly that living things had a chance to evolve protection against the effects of salt water and other minerals. Plants that live in the ocean protect their cells by having non-living cell walls. Animals that live in the ocean have protective skin, and they have evolved ways of getting rid of excess salt.
The same can be said about deserts, the arctic, and rain forests. All have hostile environments for cells. All cells have had to evolve some way to protect themselves from the effect of these environments.
Our own bodies are a good example. We have dead outer skin to keep us from losing too much water and to protect us from sun and wind. We can produce heat to keep our cells at the right temperature, and sweat as a cooling mechanism to keep us in balance.
Plants have had to go through the same process. Bark on trees is made up of dead cells which keeps them from drying out. The leaves of plants evaporate water which helps keep the cells in a temperature range so that they can function.
Because the physical changes on the planet are constantly changing, the process of evolution continues. We humans have a short life span compared to the earth, that we must use science and scientific instruments to measure the rate of evolution. Considering the fact that we have only been at it for such a short time we have made amazing progress. It is true that the whole story of evolution is all around us and maybe we should have seen it sooner, but there have always been doubters standing in the way of scientific knowledge. Now there is no major college or university in the world, that carries on scientific research, that does not accept the facts of evolution. The only theory involved is how it took place and is continuing to take place.
Charles Darwin realized that the small changes that take place every day had a great effect on evolution. He knew that all living things were under pressure to adapt to these changes.
"The plough (plow) is one of the most ancient and most valuable of man's inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earthworms. It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures. Some other animals, however, still more lowly organized, namely corals, have done more conscious work in having constructed innumerable reef and islands in the great oceans; but these are almost confined to the tropical zones." From The Formation of Vegetable Mould, through the Action of Worms, by Charles Darwin; 1881, page 313.
When Charles Darwin and Alfred Wallace presented their joint paper on evolution in 1858, nothing was known about genes and DNA. Gregor Mendel had worked out the basics of heredity, but his papers were not widely read. In 1858, heredity was thought to be a blending of characteristics from both parents. Something like mixing paint. Mix black and white paint and get gray. No matter how many times gray paints are mixed the result is never black or white. Obviously something was wrong with the blending idea. Because of this lack of knowledge, it was impossible to answer all of the critics of evolution.
In the years since 1858, an unbelievable amount has been learned about heredity. It is now possible to answer almost every challenge offered by the detractors of evolution. It was an amazing discovery when it was found that all living things have DNA that control their structure and behavior.
We can show that a characteristic can stay hidden for generations and suddenly show up. We can trace the changes in a gene, a mutation, through generations. We know the chemical make up of DNA, and can show the similarities and relationship of DNA of one species to another. By studying the DNA, we can tell if a rose bush is more closely related to a tulip or cactus. We can tell if humans are more closely related to chimps or gorillas.
Everyone knows that genetics is a powerful tool in crime detection and determination of family relationships. Yet, some people refuse to believe that the knowledge that is known about genetics can be applied to evolution.
Science is now able to determine what genes most living things have. This is very important, but it means that they still must determine what they do and how they do it. This is a gigantic undertaking, but it will be done.
So far every new discovery that has been made concerning DNA, genes, and their place in nature has added more proof to the fact of evolution. The theories of how evolution occurred are being uncovered every day in scientific laboratories world wide. This can be done because predications can be made about what will happen if genes are spliced from one living thing to another.
One of the most rewarding aspects of this knowledge is its use in medicine, known as "red biotechnology." Some diseases are already being treated by using this method.
Genes from bacteria have been transferred to potatoes and corn to protect these crops from insects. Genes have been transferred from bees to crops to protect them from fungus. This is known as "green biotechnology."
Industrial "white biotechnology" has already produced goats which have spider silk protein in their milk. This silk is extracted and used to make medical instruments that are much stronger than steel or plastic.
Humans have entered the arena of evolution by being able to change characteristics of living things that will then be passed on to future generations. The knowledge about evolution is increasing so fast that it is almost impossible to keep up with all of it. The basics of Gregor Mendel's work is still important, but like all science, be it evolution, genetics, medicine, or physical science, new important information is being added almost daily. That is why science works. We can gather new evidence and if necessary, change our minds. It can even change the way we perceive life. I am sure that even more amazing things await future generations.
"If the major problem with the fossil record is its incompleteness, then the major problem with molecular evidence for evolution is just the opposite - there is so much information that researchers can't analyze it fast enough." From Life 4th ed. by Lewis, Gaffin, Hoefnagles and Parks; McGraw Hill 2002 page 330
John Jones believes in alchemy, the transmutation of base metals into gold. Don Miller believes in phlogiston, a belief which states that a volatile substance is found in all combustible materials. Dick Smith believes in intelligent design, and Tom Taylor believes in ESP and psi phenomena. Each is an expert in their particular belief. Each would like time to explain their theory to high school science classes.
This presents a problem to educators. Although these four men are fictitious, the beliefs are not. To be more exact, these are examples of "failed hypotheses." They did not pass the scientific method of testing. They are hypotheses that will not become scientific theories. If the proponents of these hypotheses want them taught in the classroom, they must first of all convince scientists that the scientific method has been followed and that empirical scientific evidence is available for everyone to examine. The reason that scientists remain unconvinced of each is that there is no theory on how they work.
The public school classroom is no place to argue the viability of a scientific theory. Scientists should determine what science is, and that is what should be taught. But more important is to teach how science works. What is the scientific method, what constitutes empirical evidence, and what evidence is necessary to form a theory, are to questions which students of all ages should be exposed.
The overwhelming evidence is that these hypotheses do not meet scientific standards. If they are to be discussed, it should be as examples of failed ideas.
Of these examples here, only intelligent design is being suggested in today's educational circles. The definition of intelligent design is not only rejected by scientists, but also the United States Supreme Court. The people who support it have not described the mechanism, a model, or how it advance our understanding of such things as medicine, agriculture, and dozens of related fields.
The main thrust of intelligent design is to attack evolution. This has nothing to do with science. Any theory must be able to stand on its own. The burden of proof rests with the hypothesis. Statements that evolution is wrong and therefore intelligent design must be right is, not only unscientific, but not logical.
In the days before Charles Darwin, and even during his time there were many who realized that species were not static. A common term used then was transmutation. After all, farmers and even some scientists could see that there were changes within a species and the close relationship between species could also be observed. Darwin's great contribution was to show a way that this could happen.
Once Charles Lyell and others showed that the earth was not six thousand years old, but at least millions of years old, Darwin saw that there was time for natural selection to take place.
Darwin used artificial selection, fossils, geographic distribution, and anatomical structures to support the theory of evolution. We know now that the picture was far from complete. Darwin and others thought that offspring resulted from a blending of something from the parents. Something like mixing white and black paint to get gray paint. This made evolution difficult to explain. With the discovery of genes the picture became more clear, but more needed to be discovered.
Within a short period of time, not only was DNA and RNA discovered, we now know that there are bits of chemicals (viral genes) that are attached to strands of DNA that effect inheritance. All of this information has resulted in a much better definition of evolution and how it works. That does not mean that the evidence that Darwin used was wrong, it just means that we now have the answers to many questions that Darwin could never have answered.
Any good scientific definition should be as simple as possible. The definition for photosynthesis is short and simple. It is the process that is complicated. Not so with evolution. The definition is short and simple. The process is also simple, and easily understood.
Biology text books are now using a definition accepted by almost all of science. BIOLOGICAL EVOLUTION IS CHANGE IN THE GENETIC MATERIAL OF A POPULATION OVER TIME.
We must keep in mind that this refers to all of the chemistry effecting inheritance.
It is these changes reacting in different environments that determine if a species succeeds or becomes extinct.
The purpose is to separate Darwinism from evolution. We understand how important Darwin's work was and how the evidence he used proved the theory. That was over 150 years ago. New discoveries, new ways of interpretation, and vast improvements in scientific instruments have made evolution an undeniable fact. We will continue to explore different avenues, and I am sure that much more amazing information will come forth in the future.
From now on when confronted by creationists or those who accept intelligent design, we should use the correct definition and take Darwinism out of the argument. Attacking Darwinism should fall on deaf ears. The argument can now be, as it always should have been, about science and not individuals.
"Every tribe has had its origin myth - its story to account for the universe, life and humanity. There is a sense in which science does indeed provide the equivalent of this, at least for the educated section of our modern society. Science shares with religion the claim that it answers deep questions about origins, the nature of life, and the cosmos. Scientific beliefs are supported by evidence, and they get results. Myths and faith are not and do not. From River out of Eden, by Richard Dawkins, 1995, page 32.
The Formation of Vegetable Mould, through the Action of Worms, Charles Darwin, 1881
Autobiography of Charles Darwin, Edited by Nora Barlow, 1958
Darwin and the Beagle, Alan Morehead, 1969
The Survival of Charles Darwin, Ronald Clark, 1984
CROCODILES AND ALLIGATORS, FACTS ON FILE, 1989
BIOLOGY, Arms and Camp, 4th, 1995
Charles Darwin His life and discoveries, Caroline Overy, 1997
BOTANY and Introduction to Plant Biology; Mauseth,1998
Biology, the unity and diversity of life, Starr and Taggart, 9th, 2001
National Center for Science Education Report, The Origin of Whales and the Power of Independent Evidence, Raymond Sutera, Sept/Oct, 2000,
SCIENTIFIC AMERICAN, Biotech's Clean Slate, editors, Oct. 2003
"And that's all I have to say about that." Forrest Gump
Jim Strayer earned a Bachelor of Science Degree from Eastern Michigan University and a Master of Science Degree from the University of Michigan.
Since earning these degrees, he has attended Pratt University in New York to study chemistry; Wayne State University in Detroit to study ecology; and Michigan State University to study environmental problems. He has thirty-four years of teaching experience: twelve at the high school level and twenty-two at the community college level. He was given the "Outstanding Teacher Award" in 1985, and was given Emeritus standing at Washtenaw Community College in 1988, He was presented the Florida Humanist Lecturer of the Year Award in 1993. He is a liaison for the National Center for Science Education, Inc. representing central Florida.
His publications are: A Simple Method of Preparing Skeletons, Metropolitan Detroit Science Review, December 1967; Living Crayfish in the Laboratory, The American Biology Teacher,Vol 31 No. 3, March, 1969; A Simple Method of Taxidermy, American Biology Teacher, March 1969; Microscopic Photography, The American Biology Teacher, June, 1971; Preserving Snakes in Glass Tubing, TURTOX News Letter, August, 1974; The Scopes Evolution Trial, The Battle Continues, Humanists of Canada, Fall 1994 (#110); The Golden Silk Spider, Florida Wildlife, May-June 1994, Vol. 48, No. 3; Thomas Huxley Debates Bishop Wilberforce, Humanists of Canada, Winter 1993/94 (#107); Creating Creationists; Creationist's Use Of "Science" Texts, American Atheist, Summer 2001, Vol. 39, No. 3; and he has co-authored an article, Creation vs. Evolution: Effects on Learning Biology; March 2002, American Biology Teacher.
