Oct
12
2005

A visitor to this website recently posted this question:

How is evolution proved right? How is there proof of this "chance?" There are many other ways people say the earth was created; which is right? Is there a God that created the world? Or did everyone simply evolve? Whatever you believe, how do you prove yourself right?

Here is the Science Museum of Minnesota's official position on evolution.

That said, "proof" is really the crux of the issue.

All explanations of the Earth's creation other than evolution basically say that life is too complicated to explain by natural processes; something outside of nature must have created it. The only way to prove or disprove an idea like that is to look outside of nature. And once you go outside of nature, you're no longer doing science.

Science is a way of looking at the world, asking questions about nature and looking for answers in the natural processes around us. It works on one simple rule: show us the evidence! Show us an experiment in the lab or an observation in nature, but you have to point to something real that can be seen or measured. And then you have to come up with an explanation for what you've seen. You have to test your explanation by doing another experiment or making another observation that supports you. And if the results don't match, you know your explanation was wrong.

In science, a theory is an explanation that accounts for all the evidence. Atomic theory explains how matter works. Gravitational theory explains how gravity works. And evolutionary theory explains how life has changed over time.

Evolution is both a fact and a theory. The word has two meanings. First, it means "the history of life on Earth." And there's no denying that life has changed over the last 500 million years-go to the Dinosaurs and Fossils Gallery and see for yourself. But evolution also means "the explanation of HOW those changes have occurred." Scientists use the word theory for explanations that account for all the evidence.

And there is a lot of evidence for the theory of evolution. Every fossil that's ever been found; every animal that ever lived; every cell in your body-all of these support evolution. Scientists have been poking and prodding and testing the theory for 150 years, and have written tens of thousands of papers on the subject. Evolution is the best explanation we've ever had for the history of life on earth. (In terms of experiments and observations, it has been said there is more solid evidence for evolutionary theory than for atomic theory-and no one doubts the existence of atoms!)

Evolution happens every day, all around us. The bird flu that's been in the news is an example of evolution in viruses. New breeds of farm plants and animals are examples of evolution. And every baby that is born today will inherit traits from its mother and father, and so also be an example of evolution in action.

Science is really good at explaining WHAT and HOW: what our bodies are made of, how they work, how we evolved. But one thing science cannot do is explain WHY. Why are we here? What is our purpose? What is life's meaning? For that, you need religion.

OK, so what is evolution?
Evolution, by the most basic definition, is the profound, ceaseless change in life forms through time.

Charles Darwin and Alfred Wallace were the first scientists to call this change in life over time "natural selection," although many others have contributed to the idea. (Changes in the theory of evolution have been made since Darwin's original proposal, yet his main theory stands firm.)

The theory of natural selection is based on three principles:

  • Organisms produce more offspring than can survive and reproduce.
  • Those that do survive tend to be better adapted to local environments.
  • Most adaptations are genetic, so they can be passed from parent to offspring.

Generation by generation, organisms that are better adapted to their environment in some way survive to pass on their advantageous qualities.

Evolution is not purposeful: it does not work toward a specific end or create better or worse organisms. Species evolve by adapting to particular niches in their environments, but the genetic mutations that lead to these adaptations occur by chance. An organism cannot will itself to mutate in a beneficial way. If its niche disappears, the species may become extinct or it may adapt to new conditions, but the failure to do so does not imply some kind of defect.

Evolution does not occur "for the good of a species." It operates at the level of individual organisms over many generations. A whole population does not simultaneously evolve a new trait; instead, the new trait evolves in one or a few organisms, which pass it on until the population is dominated by organisms having that trait.

Even more evidence of evolution
As humans, we share features with all living life forms, past and present. The more specific these features are, the more recently scientists think they evolved. For example, fingernails-a feature we share with all primates-evolved 30 million years ago. We have the same basic anatomical plan as all other vertebrates, which evolved 500 million years ago. And our cells'ability to use oxygen goes all the way back to our relationship with plants, fungi, and bacteria, which evolved over 1,000 million years ago.

Here are other examples of evidence for evolution:

  • Some animals have organs that serve no purpose but have a function in other species. Such a structure is referred to as vestigial. Whales, for instance, possess useless pelvic bones left over from their land-dwelling ancestors. Fossil whales are found with tiny limbs that became increasingly unimportant.
  • Many closely related species live in proximity to one another but are separated by a geographical barrier. (It was observations like this on the Galapagos Islands that helped Darwin formulate his theory of natural selection.) For example, two similar species of fish live separated by Central America: one in the Gulf of Mexico, and the other in the Pacific Ocean. They evolved when the Isthmus of Panama formed and separated their common ancestor's population into two groups. If the fish had not evolved after they were separated, the same species would live on both sides of the isthmus. And if they hadn't descended from a common ancestor, they wouldn't be so similar.
  • As we develop more types of antibiotics, new resistant strains of bacteria evolve through natural selection. Many crop pests have also evolved strategies to cope with our use of pesticides. Some species of grass have even evolved ways of thriving on industrial waste.
  • Through artificial selection, humans have developed new plants and animals. By manipulating genes, we have obtained many different types of crop plants-some produce greater yields, some produce higher concentrations of their own natural pesticides, and some are more resistant to drought. From a very basic canine type, we developed many different breeds of dogs over the last few thousand years. Artificial selection is somewhat analogous to natural selection; the difference is in the selective force-humans, instead of nature.
  • All multi-celled creatures share distinct genes for developing body plans (like plans for limbs, eyes, etc.). These genes, called homeotic genes, are incredibly similar in all animals, even among animals as different as fruit flies and chimpanzees.

Your Comments, Thoughts, Questions, Ideas

Anonymous's picture
Anonymous says:

There are two kinds of evolution: micro evolution and macro evolution. Micro evolution is creatures adapting to their environment. Macroevolution is for example, a reptile turing into a bird. Adaptation is real. But if someone says that a reptile evolved into a bird, do they really have any proof? Did they see it happen?
Lucy, the "ape woman", long supposedly the "missing link" turned out to be nothing but and extinct species of ape.
Say a woodpecker started out as just a bird. A woodpecker has an extremely hard bill and skull to make up for the force of which it slams its bill against a tree. Also, to reach the insects inside the tree, it has a very long tongue. It doesn't coil up its toungue inside its mouth. It actually wraps its toungue under its scalp, on its skull.
Now, suppose a cosmic ray hit baby bird and gave it a hard skull. The bird happens to decide to decide to whack its head against a tree. Well, its skull won't crunch, but since it's bill is just a bill, it will. Then you have a dead bird who can't pass its genes on.
Say the bird got a hard bill instead of a hard skull. It whacks its head against a tree, and the bill is fine, but this time its skull fractures. Dead bird.
And say it got a long tongue. Then it's just flying around with this long tongue hanging out of its mouth.
Evolution takes just as much faith as believing in an all powerful Creator. To me, it would take even more faith to believe in evolution.
The first amendment gives the right of speech and the right of religion. Therefore, it evolution can be taught in schols, Creation should be too.
Separation of church and state was not meant to keep God out of schools. If that were so, then money, which has In God We Trust on it, should be banned too.
If evolution is correct, then we are all evolved from pond scum. Everything is. With all the diversity in our world today, I find that very hard to believe.
Also, the conditions of our earth are exactly right to suppot life. The tilt, distance from the sun, rotation, even how far away our moon is, all fit into a very narrow margin, perfect for life.
If all the planets were evolved from a Big Bang, then they'd all have a very similar composition, tilt, rotation moons, etc. But they don't.
In the end, it takes faith to believe in either evolution of Creation. There is no absolute certainty except for your faith in either one. Therefore, both should be taught in schools.
With God removed fromour schools/country, no wonder peoples morals have degraded so much!

posted on Fri, 06/02/2006 - 12:23pm
Gene's picture
Gene says:

Researchers at Michigan State University have created a computer program called Avida which proves evolution works. The program takes the basic principles of evolution--variation, inheritance, selection, and time--and shows that that's all you need to grow a diverse living system. One of the scientists involved in the project says "...Avida is not a simulation of evolution; it is an example of it."

posted on Thu, 10/13/2005 - 4:47pm
Anonymous's picture
Anonymous says:

"Proof" for historical events are impossible to come by. Can you prove that George Washington was the first president of the United States? What we need to be seeking is a high confidence level in a proposed allegation, or theory. Does the evidence we have right now fit into the theory we create? If so, how well, and does the evidence fit into another theory better? That's the crux.

The other explanations of the Earth's creation also say (1) the evidence doesn't support the evidence and (2) some evidence shows natural processes cannot do what evolution requires.

"Show us the evidence!" An increasing number of scientists (and students) are actually looking at the evidence for what it is and finding the theory of universal common ancestry as an explanation for all of life's origins wanting. The fossil evidence does not fit the theory. The Cambrian explosion produced nearly all phyla that ever existed, and (mainstream) scientists now believe the explosion took place as rapidly as 50 million years (some think 30 million). The horse and whale fossil lineages show nothing more than variation within the whale and horse types, and the "missing link" for humans is still yet to be found. Molecular biology and genetics is finding operations within cells more and more complicated and making the feasability of de novo features mutating into existance slimmer each year. Avida does not come close to mimicking life. Given more realistic parameters, error catastrophe is inevitable. Richard Lenski's work on E.coli has been lackluster, and the best efforts to mutate dessication resistance in D.Birchii have failed. All these examples illuminate a fundamental problem to the theory of universal common ancestry.

These are but a few pieces of evidence that come immediately to my mind.

Evolution is a strange word. I've seen the word defined over a hundred times and each time the definition is different. Informed anti-evolutionists actually agree that adaption, natural selection, speciation, and the ambiguous "change in time" are empirical facts. Anti-evolutionists agree that natural selection is not purposeful or "for the good of a species." The part they object to is the "mainstream" extrapolation of observed variances of populations and connecting dots where (molecular and fossil) evidence shows connections couldn't have been made. What results from this conclusion is non-universal common ancestry (and enter God).

The "even more evidence" cited in the blog I find curious. For one thing, why did the author feel the need to cite evidence for a "mainstream" theory? That's like saying "trust me: gravity is a good theory because rocks fall down." For another, most of the evidences cited aren't really evidences for universal common descent at all but for the emperical "change in time" that anti-evolutionists agree to. Comparitive analysis does not speak for itself. (For a simplified example, a comparison of the bat wing and the bird wing alone can lead to false conclusions.) The blog writer is silent on the question of the actual molecular mechanism that would enable novel features and genes to mutate into existance. This evidence would be powerful for evolutionists, but science is having difficulty finding it.

Calling 40% of science museum visitors "illogical" is a bit narrow-minded. Thorough investigation of their reasons is called for. Possibly they see something others do not. (On the other hand, Jay Leno repeatedly shows the vast majority of Americans are idiots....) Also, keep in mind that the idea that science must be 100% naturalistic is an a priori assumption that has not been proven. Evolutionists also rely on faith.

posted on Tue, 05/30/2006 - 5:03pm
RussD's picture
RussD says:

This sort of thing has been done a number of ways. The first time I saw this it was done with virtual 'animals' that could move in simple ways and were allowed to rendomly mutate over many generations, the ones that could translate themselves over a distance were allowed to survive and mutate...the results were fascinating. Even this simple model, a small number of the virtual animals evolved ways of moving that that are similar to REAL animals.

See Karl Sims site

Russ

posted on Fri, 10/14/2005 - 10:18am
Gene's picture
Gene says:

There is no distinction between microevolution and macroevolution. They work by the same process. "Macroevolution" is simply the accumulation of many tiny changes.

Evolution does not change an entire feature all at once. In the woodpecker scenario, the birds lived in an environment where a stronger skull, a stronger beak, and/or a longer tongue gave some advantage. The individuals whose skulls / beaks / tongues were slightly stronger / longer had an advantage, lived longer, had more offspring. Repeat the process for many generations, and the woodpecker evolves.

Evolution is based on many lines of evidence. Faith -- which is a wonderful and powerful thing -- is based on received wisdom.

The "right of religion" also includes a clause which says the government shall not "establish" a religion. This has been interpreted as meaning the government can't use taxpayer money to support any particular religious belief.

There is no reason to believe that the Big Bang would result in all planets being exactly like Earth. Roll eight dice, and will all eight come up with the same number? Probably not.

posted on Thu, 01/25/2007 - 1:37pm
Gene's picture
Gene says:

You are using "prove" in the mathematical sense of a logical argument which, based on its premises and definitions, has one and only one conclusion. Other fields of study are not like that. In history, law and science, "prove" means "to demonstrate beyond reasonable doubt, using the preponderance of evidence." Hisotirans can demonstrate beyond reasonable doubt that George Washington was the first President. Scientists can, and have, demonstrated beyond reasonable doubt that evolution has and does occur.

posted on Thu, 01/25/2007 - 1:44pm
Liza's picture
Liza says:

The American Museum of Natural History is opening a new traveling exhibition about evolution. Cool.

posted on Mon, 11/07/2005 - 11:04pm
Liza's picture
Liza says:

Here's the New York Times's complete coverage of the evolution debate.

Note: while there is public debate over evolution, there is no debate among mainstream scientists.

posted on Mon, 11/07/2005 - 11:09pm
Anonymous's picture
Anonymous says:

Explain why Darwin's first rule of natural selection applies to humans. The first rule of natural selection is that organisms produce more offspring then can survive.

posted on Wed, 11/16/2005 - 4:45pm
Gene's picture
Gene says:

I thought Darwin's first rule was variation -- that each individual is unique and, in certain circumstances, may have a survival advantage which they can pass on to their descendants.

I believe you are thinking of Malthus. And yes, that does apply to humans. Infant mortality rates are not zero. World wide, 8% of newborns do not survive infancy. In some countries, the rate approaches 20%. Famine and disease are the biggest killers. Many people exposed to famine and disease die. But some survive, and may pass on their resistance.

posted on Thu, 11/17/2005 - 2:40am
Liza's picture
Liza says:

The American Association for the Advancement of Science (AAAS) has played a prominent role in responding to efforts in Kansas and elsewhere to weaken or compromise the teaching of evolution in public school science classrooms. Here are some background materials on the controversy and links to AAAS resources on evolution.

posted on Thu, 12/15/2005 - 12:39pm
Anonymous's picture
Anonymous says:

How can 40+% of visitors to a Science Museum think intelligent design is an explanation for how species have evolved? Isn't that a contradiction?

posted on Mon, 12/26/2005 - 2:34pm
Liza's picture
Liza says:

Well, they aren't necessarily visitors to the museum. They could be people who visited the site on the Internet. And some people are looking for an argument...

posted on Mon, 12/26/2005 - 9:13pm
bryan kennedy's picture

True. And, it is sometimes a struggle at the museum to try and figure out who is really interested in learning the science perspective and who is really just looking for an argument.

posted on Tue, 12/27/2005 - 2:19pm
Dan's picture
Dan says:

I think you can narrow it down to three general reasons for the illogical acceptance of ID over that of evolution.

Firstly, the need to believe in a purposeful reason for their existance. We seem to have a lot of trouble letting that one go.

Secondly, the need exists , it seems, to place our specie above that of all the rest. We are special, they are not. We are more advanced, they are not...and so on.

Lastly, The afterlife is a cushion against nonbeing..death is not an option.

Religion offers answers to all the above..abit..illogical and faith based...but answers none the less.

posted on Tue, 01/03/2006 - 10:39pm
Anonymous's picture
Anonymous says:

interesting exhibit, but kind of eerie, even if it is true.

posted on Sun, 07/16/2006 - 7:02pm
Sherwin123's picture
Sherwin123 says:

Though how the Universe really started can still be debated upon and fiercely protected by creationalists, there is no doubt that evolution is how most animals and humans came to be. I find that rejecting all the evidence is just foolish.

posted on Sun, 02/05/2012 - 9:58pm

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