Evolution

The definition of evolution as Charles Darwin presented it, and as modern biology continues to show us, has two simple parts:

1. Living things have descended with genetic modification – evolved – over time from common ancestors

2. Natural selection – those organisms most effective at reproducing – is the main, but not the only, mechanism of evolution

“There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one: and that whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”

The theory of evolution is the only scientific explanation we have for the diversity of life on Earth. But it’s hard to understand evolution without an understanding of the eons of time it took for evolution to occur.

Here’s an exercise to help you visualize the enormity of the time frame scientists are talking about when they examine evolution (from Jamie Crannell, Chaska High School Chemistry teacher):

The universe is about 13.7 billion years old. Earth is about 4.6 billion years old.

Bring a piece of corrugated cardboard to your local football field.

Begin at one goal line and walk 100 yards to the opposite end of the field.

You've just walked a timeline representing the age of the Earth - 4.6 billion years

Now, stand the cardboard on end on the goal line.

That’s how long humans have been on Earth – that little sliver of time, the thickness of the cardboard - about 160,000 years.

But what about the monkeys? Biologists studying evolution have determined that modern humans (Homo sapiens) evolved from an earlier human species (most likely Homo ergaster). Homo ergaster in turn evolved from a still earlier human species which, if we go back about 6 million years, evolved from an ancestral great ape. Chimpanzees are also descended from this same ancestral great ape. We share about 96% of our DNA with chimpanzees. The really interesting story will be in that 4% (which equals about 40 million genetic differences) and the millions of years separating us!

The tree of life (http://tolweb.org/tree/phylogeny.html) is more accurately described in the shape of a shrub with roots and many branchings – some led to extinction, some led to redwoods and sunflowers, some led to fish and lizards, some to saber-toothed jungle cats and housecats – one led to monkeys and apes, then branched yet again to humans.

Darwin’s theory of evolution shows us that virtually all life on Earth is related; neo-Darwinian theory, which continues to build on the original theory, gives us more information since the discovery of genetics and DNA.

Obviously, life had to be present before the process of evolution could occur. Evolutionary biologists accept from scientific evidence that single-celled organisms first appeared on Earth as early as 3.8 billion years ago.

Many scientists, like many of their fellow citizens, cherish their faith in the divine creation of this early life. Sean B. Carroll is one such scientist; he’s a molecular biologist who specializes in evolutionary development. Dr. Carroll is a professor and researcher at the University of Wisconsin-Madison, and author of Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom.

Francis S. Collins of the National Human Genome Research Institute is another scientist who often speaks and writes about his Christian faith. Dr. Collins led an international group of 67 scientists who announced the mapping of the chimpanzee genome, human beings’ closest relative. (Nature, September 1, 2005) more here

Kenneth R. Miller, a biology professor at Brown University, is the author of a widely used high school Biology textbook, and a practicing Roman Catholic. Dr. Miller explains how he’s reconciled the theory of evolution with his religious faith in his book Finding Darwin’s God.

The National Center for Science Education keeps a list of religious organizations which see no conflict between their theology and the theory of evolution:

There are exceptions: Evolution is not compatible with a literal reading of creation in the Book of Genesis.

However, science is necessarily silent about the existence and influence of God. Science does present evidence that is occasionally in conflict with specific statements in religious texts if interpreted literally. For example, scientists agree that life began on earth at least 3.8 billion years ago; Young Earth Creationists believe the Earth is 6,000 years old, dinosaurs lived in the Garden of Eden with humans and the Grand Canyon was formed by Noah’s flood. read more here
Regardless of their personal beliefs, evolutionary biologists use scientific methodology to critically examine their own and their colleagues’ work, just like every other respected and reputable scientist in the world.

If scientists discover tomorrow that life originated with a combination of chemicals, or by an electrical spark, or from a falling star, science would still be silent on divine intervention. And science would still explain our physical, material universe of matter and energy by testing theories with physical, material means.

“Science, fundamentally, is a game. It is a game with one overriding and defining rule:

Rule No. 1: Let us see how far and to what extent we can explain behavior of the physical and material universe in terms of purely physical and material causes, without invoking the supernatural.”

In the Minnetonka schools, the 7^th grade Science curriculum covers evolutionary biology, and students study it again in Biology (usually 11^th or 12^th grade) in high school. The State of Minnesota, through its legislature, requires high school students to have at least one credit of Biology.

Most colleges and universities want to see a Biology credit on a student’s transcript. But evolution underpins almost all of science, not just biology – it’s integral to geology and astronomy, and important to understanding physics and chemistry.

You can see the Minnesota Science Standards on the MN Department of Education web site. Go here and scroll down the page - you'll see instructions to open a Word document containing the standards.

Teaching science without fully teaching the scientific theory of evolution, or teaching students to doubt the validity of evolution makes about as much sense as teaching math without the number 666 because that number represents Satan to some people, or teaching the English language without the vowels a, i and u because those letters are used in swear words.

We could almost do it – with a lot of twisting and bending and maneuvering -but think what our kids would be missing!

“Intelligent Design” is not science. It’s a religious concept – the latest version of creationism.

Science doesn’t replace scientific questioning with religious certainty; our children’s science education shouldn’t either.

Teaching students that there is a “scientific controversy” about evolution or that science has “alternative theories” to evolution is wrong because it’s simply not true. Introducing religious concepts is a waste of valuable time in science classrooms.

Teaching students that an “Intelligent Designer” is the answer to anything science can’t yet explain violates that most American of values, the separation of church and state. If we teach religious concepts in public school classrooms, whose religion do we include? Whose do we leave out?

There is no substitute for a solid understanding of the science of evolution. We are cheating our children of an excellent education if we pretend otherwise.

We accept the theory of gravity; we know exactly what will happen if we jump off a bridge or a tall building. We accept the germ theory of disease; we refrigerate our food and wash our hands before we eat.

Scientists continue to expand and refine these and other theories, but very few people question the principles behind these theories.

Scientific Theory: a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses

Yes, they do. Scientists devote most of their time to questioning, critiquing and analyzing their own and other scientists’ work. They use scientific methodology – and only scientific methodology – to do this because they want their work to stand up to the scrutiny of the public and the scientific community. Respected and reputable scientists are perfectly comfortable having other scientists tear apart their work and examine every detail – even if the conclusion is different.

But asking elementary, middle school or high school students to understand the finer work of PhD level biologists without first giving them a solid background in the science of evolution is an exercise in frustration and confusion.

Minnetonka students are smart, but most of them can’t afford to skip right over the basics.

And if we want them to be scientifically literate, and to succeed in college, maybe even to major in the sciences or medicine, shouldn’t we make sure they’re fully prepared?

TonkaFocus thanks the following individuals for their help in preparing this article:

Jamie Crannell, Chemistry Instructor, Chaska High School, Member of the Minnesota State Science Standards Committee

Ed Hessler, Center for Global Environmental Education, Hamline University
Scott M. Lanyon, Director, Bell Museum of Natural History; Professor, Dept. of Ecology, Evolution, and Behavior, University of Minnesota
Melanie Reap, Associate Professor of Education, Winona State University, Member of the Minnesota State Science Standards Committee

“Nothing in Biology Makes Sense Except in the Light of Evolution” by Theodosius Dobzhansky

“New Analyses Bolster Central Tenets of Evolution Theory”, published September 25, 2005 in the Washington Post

“One Side Can Be Wrong” by Richard Dawkins and Jerry Coyne, Published September 1, 2005 in The Guardian

“Intelligent Design Has No Place in the Science Curriculum” by Harold Morowitz, Robert Hazen, James Trefil

“Grasping the Depth of Time as a First Step in Understanding Evolution” by Verlyn Klinkenborg