One in a series of letters to my son that I wrote to strengthen him as he began his high-school years
Many storylines from evolution fall apart when you look at them closely and question the details. A good example is your biology textbook's story about how the first organic molecules were formed. Read the first few sentences on evolution. You'll find them on Page 252. Here's how the story in your book begins:
"When Earth formed, about 4.5 billion years ago, it was a fiery ball of molten rock. Eventually, the planet's surface cooled and formed a rocky crust. Water vapor in the atmosphere condensed to form vast oceans. Most scientists think life first evolved in these oceans and that the evolution of life occurred over hundreds of millions of years." (1)
So how did life evolve in the oceans? Look on the next page, under "Formation of the Basic Chemicals of Life". Here's what you'll find:
"Most scientists think that life on Earth developed through natural chemical and physical processes." (2)
OK. That's fine. But what specific processes might we be talking about? Turn the page to read about the primordial soup model. You'll learn of a famous experiment in 1953 by Stanley Miller and Harold Urey. They put some gasses and water vapor into a glass apparatus and zapped the contents with electric sparks. The result was, in the words of your textbook: "some basic chemicals of life".
Your textbook authors spend the better part of a page on Miller-Urey before finally admitting that what they've been telling you fails to explain how the needed chemicals came to be. Here's what you'll find under "Reevaluating the Miller-Urey Model":
We now know that the reductant molecules used in Miller's experiment could not have existed in abundance on the early Earth.
Without ozone, ultraviolet radiation would have destroyed any ammonia and methane present in the atmosphere. When these gases are absent from the Miller-Urey experiment, key biological molecules are not made.
If the chemicals needed to form life were not in the atmosphere, where did they come from?
The correct answer has not been determined yet. (3)
"Ultraviolet radiation would have destroyed any ammonia and methane...". Any! So Miller-Urey's experiment proves nothing. To their credit, the authors admit as much in their final words: "The correct answer has not been determined yet.". Those words are a fancy way of saying that the authors have no explanation to offer.
It must be unsatisfying to end a section on the "Formation of the Basic Chemicals of Life" without actually explaining the formation of the basic chemicals of life. So the authors trot out "The Bubble Model". If you can't get the ammonia and methane from the atmosphere, perhaps you can fart in the tub instead. Ready? Here we go:
In 1986, the geophysicist Louis Lerman suggested that the key processes that formed the chemicals needed for life took place within bubbles on the ocean's surface.
Thus, the molecules of life could have appeared more quickly than is accounted for by the primordial soup model alone. (4)
Suggested? Could have? The authors' explanation here is weak sauce. The authors cite no trail of evidence leading up to the Bubble Model. They mention no fossilized bubbles. They do not cite any experiments to validate the model. They just trot out this fanciful tale that life began in blowing bubbles, and tell you that it "could have" been that way. That's weak sauce my son, weak sauce indeed.
What your textbook authors are essentially telling you is that:
- Chemical reactions on early Earth produced organic chemicals.
- Miller-Urey demonstrated those reactions in a lab.
- After some years we realized that Miller and Urey were wrong.
- We decided to like blowing bubbles instead.
Your textbook makes a weak case. The case gets even weaker, almost dishonest, when you dig into the details. The article Survival of the Fakest (PDF) (from The American Spectator, December 2000-January 2001) contains a section debunking Miller-Urey. Another good article is Jerry Bergman's Why the Miller–Urey research argues against abiogenesis. (The word "Abiogenisis" refers to creating life from non-living matter. Bergman argues that life can not arise from non-life).
Son, your textbook section on the "Formation of the Basic Chemicals of Life" ends without actually explaining anything. Do you see that? The authors do not prove the Primordial Soup model. They admit the Miller-Urey model is flawed and inadequate. They offer no evidence at all, of any sort, in support of the Bubble Model.
Read your textbook critically. Question the details. Push back against the hand-waving. Reject weak-sauce arguments that dodge around the true questions at hand.
1) Biology; Johnson & Raven; Holt, Rinehart and Winston; 2006; 0-03-074061-4; Page 252; Chapter 12, "History of Life on Earth" -> Section 1, "How Did Life Begin" -> Section on "The Age of Earth", Paragraph 1.
2) Page 253, Section on "Formation of the Basic Chemicals of Life"
3) Page 254, Section on "Reevaluating the Miller-Urey Model"
4) Page 255, Section on "The Bubble Model"