26 October 2006

Evolution for Dummies

From a Scientific American list of 15 common attacks on evolution. I'll spare the more mundane or ridiculous items (semantics about 'theory', no one has seen evolution, etc).

6. If humans descended from monkeys, why are there still monkeys?

This surprisingly common argument reflects several levels of ignorance about evolution. The first mistake is that evolution does not teach that humans descended from monkeys; it states that both have a common ancestor.

The deeper error is that this objection is tantamount to asking, "If children descended from adults, why are there still adults?" New species evolve by splintering off from established ones, when populations of organisms become isolated from the main branch of their family and acquire sufficient differences to remain forever distinct. The parent species may survive indefinitely thereafter, or it may become extinct.

8. Mathematically, it is inconceivable that anything as complex as a protein, let alone a living cell or a human, could spring up by chance.

This explanation is good, but leaves out a key element--the vast amount of time over which natural selection has in which to work. Similarly to the vastness of space, the vastness of time is something we all have trouble wrapping our minds around. We can look at the numbers in scientific notiation, even read examples and comparisons, but at the end of the day time and space are too vast for us to really take their measure in a way we can internalize.

Chance plays a part in evolution (for example, in the random mutations that can give rise to new traits), but evolution does not depend on chance to create organisms, proteins or other entities. Quite the opposite: natural selection, the principal known mechanism of evolution, harnesses nonrandom change by preserving "desirable" (adaptive) features and eliminating "undesirable" (nonadaptive) ones. As long as the forces of selection stay constant, natural selection can push evolution in one direction and produce sophisticated structures in surprisingly short times. As an analogy, consider the 13-letter sequence "TOBEORNOTTOBE." Those hypothetical million monkeys, each pecking out one phrase a second, could take as long as 78,800 years to find it among the 2613 sequences of that length. But in the 1980s Richard Hardison of Glendale College wrote a computer program that generated phrases randomly while preserving the positions of individual letters that happened to be correctly placed (in effect, selecting for phrases more like Hamlet's). On average, the program re-created the phrase in just 336 iterations, less than 90 seconds. Even more amazing, it could reconstruct Shakespeare's entire play in just four and a half days.

11. Natural selection might explain microevolution, but it cannot explain the origin of new species and higher orders of life.

Evolutionary biologists have written extensively about how natural selection could produce new species. For instance, in the model called allopatry, developed by Ernst Mayr of Harvard University, if a population of organisms were isolated from the rest of its species by geographical boundaries, it might be subjected to different selective pressures. Changes would accumulate in the isolated population. If those changes became so significant that the splinter group could not or routinely would not breed with the original stock, then the splinter group would be reproductively isolated and on its way toward becoming a new species. Natural selection is the best studied of the evolutionary mechanisms, but biologists are open to other possibilities as well. Biologists are constantly assessing the potential of unusual genetic mechanisms for causing speciation or for producing complex features in organisms. Lynn Margulis of the University of Massachusetts at Amherst and others have persuasively argued that some cellular organelles, such as the energy-generating mitochondria, evolved through the symbiotic merger of ancient organisms. Thus, science welcomes the possibility of evolution resulting from forces beyond natural selection. Yet those forces must be natural; they cannot be attributed to the actions of mysterious creative intelligences whose existence, in scientific terms, is unproved.

14. Living things have fantastically intricate features--at the anatomical, cellular and molecular levels--that could not function if they were any less complex or sophisticated. The only prudent conclusion is that they are the products of intelligent design, not evolution.

This "argument from design" is the backbone of most recent attacks on evolution, but it is also one of the oldest. In 1802 theologian William Paley wrote that if one finds a pocket watch in a field, the most reasonable conclusion is that someone dropped it, not that natural forces created it there. By analogy, Paley argued, the complex structures of living things must be the handiwork of direct, divine invention. Darwin wrote On the Origin of Species as an answer to Paley: he explained how natural forces of selection, acting on inherited features, could gradually shape the evolution of ornate organic structures.

Generations of creationists have tried to counter Darwin by citing the example of the eye as a structure that could not have evolved. The eye's ability to provide vision depends on the perfect arrangement of its parts, these critics say. Natural selection could thus never favor the transitional forms needed during the eye's evolution--what good is half an eye? Anticipating this criticism, Darwin suggested that even "incomplete" eyes might confer benefits (such as helping creatures orient toward light) and thereby survive for further evolutionary refinement. Biology has vindicated Darwin: researchers have identified primitive eyes and light-sensing organs throughout the animal kingdom and have even tracked the evolutionary history of eyes through comparative genetics. (It now appears that in various families of organisms, eyes have evolved independently.)

Today's intelligent-design advocates are more sophisticated than their predecessors, but their arguments and goals are not fundamentally different. They criticize evolution by trying to demonstrate that it could not account for life as we know it and then insist that the only tenable alternative is that life was designed by an unidentified intelligence.


Anonymous said...

Addressing #14 here...

From: http://www.creationapologetics.org/

What do ‘Probability Laws’ say about evolution?

To determine the mathematical sum of evolutionary probability we must employ the two rules of mathematical probability; The Law of Averages and The Multiplication Rule. The Law of Averages determines how many runs (attempts) are required for a simple cell to gather the required information necessary to form life, before it becomes a mathematical possibility. As it continues its attempt at self-organization, however, eventually it mathematically levels out to almost absolute predictability (equilibrium)– that is, the longer run serves to average out the fluctuation that you would experience in a shorter series. The longer it takes to reach such equilibrium, the greater the odds of accomplishment.

The Multiplication Rule is a bit more involved as it is the process of counting the number of possible outcomes of each step and then multiplying these numbers.(1) This rule is most often used where the various outcomes of a particular step are all equally probable and the steps are independent.

To build your understanding of the answer, let me offer an experiment using 10 quarter-dollars numbered one through ten and placed in a baseball cap. If we are calculating the chances of grabbing the number one coin on the first draw followed by the number two coin on the second draw we would first recognize that each draw represents a 1 x 10 chance (one chance out of 10 coins). When we draw for the second coin, there are also 10 possible outcomes as there are ten coins to choose from thus, the odds of drawing the number two coin on the second attempt is 1 x 10 x 10, or, 1 in 100. So the chance of getting the two desired coins in order is 1 in 100. The probability is 1/100, on the average. This means if we make enough attempts, about once in every 100 draws, the number one coin will be followed by the number two coin.

To attempt to draw all 10 coins in order we must multiply 10 by itself until the figure is used 10 times. 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 1010, or, 10,000,000,000. In this one example (short run), chance would succeed on the average only once in ten billion attempts.

At this point short runs would produce great deviations and so long runs would be required to then institute the law of averages and average out the results. This would give us the absolute - odds, as the average number would be identified as absolute equilibrium.

As I will clearly demonstrate, the laws of chance and mathematical probability are of no friend to the worshippers of evolution. All scientists are aware the idea of life forming by natural processes has been demonstrated to be in contradiction to these laws.(2)

To calculate the odds of evolution it must first be pointed out that each promoted, evolutionary step requires an entire set of complex biological changes where a living system must increase its information before evolving to the next level. To assertain with absolute certainty, each change in itself must be subjected to these two laws. If we examine the complete evolution of dinosaurs evolving into birds, as preached by the worshippers of evolution, to properly determine the probability, each biological step must be calculated and its number will compound along the way. Since I'm already aware the odds for evolution represents a number beyond human comprehension, I will simplify the process for your understanding by calculating the evolutionary odds of a tiny insulin molecule, which is an initial step required for life to evolve.

What is the probability a protein molecule, with all of its complex designs, might have evolved and been aligned by chance? These giant molecules are the chemical basis of all life and amongst the first ones to be mapped was insulin, which is the smallest molecule qualifying as a protein. It has fifty-one amino acid "links," in two strands, one with twenty-one and the other with thirty amino acids. The two strands are joined together by "sulfur bridges."(3) To bring this about, the cell first constructs a longer chain of more than 80 amino acids called "proinsulin." It ranges in length from around 81 to 86 in various animals. We will use an insulin molecule of length 84 amino acids of which can be found in a pig to determine our calculations.

This extended sequence of 84 units causes the chain to fold and cross-bond correctly, and then a particular section of 33 units is cut out by special enzymes, leaving the final 51 amino acids in two chains properly oriented with cross links between them.

Chance will therefore need to align 84 amino acids in correct order to form proinsulin, as the precursor for insulin. Since each of the 84 positions in the chain could be occupied by anyone of the 20 kinds, the total possible arrangements is 2084, which, after conversion to base 10, is approximately 10109. The different arrangements are considered equally probable; so the probability of any one molecule being in the correct order for insulin is 1 in 10109.

Remember, this is a 1 followed by 109 zeros and this is just one extremely small step along the promoted evolutionary trail. And to maintain our perspective, this is just the odds of getting one of the 400 or more proteins of the hypothetical minimum cell proposed by the evolutionists (real world ‘simple’ bacteria have about 2,000 proteins and are incredibly complex). Moreover, the program of the cell, encoded on the DNA, is also needed. In fact, the idea of such a simple cell forming by chance, using all the required ingredients, is worse than 1 in 1057800 – that is a 1 followed by 57,800 zeroes.(4) To put this number in perspective, it would take 11 full pages of magazine type to print this number.

So we can see the microscopic chance of the formation of an insulin molecule being a number most people will never understand and as we migrate up the process to that of a fully developed cell, the numbers are beyond our comprehension. Dr. Emile Borel, who first formulated the basic Law of Probability, determined that the occurrence of an event where the chances are beyond 1 chance in 1050 (the 200th power is used for scientific calculations), is an event which we can state with certainty will never happen, regardless of the time allotted or how many opportunities could exist for the event to take place.(5) The mathematical probability of a single living cell arising spontaneously has been calculated over and over again by evolutionary scientists and they have been unable to come up with a figure which falls under Borel's upper limit!

Let's look at the odds for evolution within other biological processes:

Odds calculated using probability theory associated with the evolution of the gene that encodes:

• The lens in the vertebrate eye = 1 chance in 2 x 1086
• One of the many proteins required to convert food to energy = 1 chance in 1.7 x 1048
• A protein required for cell locomotion = 1 chance in 1x10177

1. Irving Adler, "Probability and Statistics for Every Man," New York, John Day Co. 1963, pp. 58-59
2. D.A. Bradbury, "Reply to Landau and Landau," Creation/Evolution, 13(2):48-49, 1993.
3. J.F. Coppedge, "Evolution: Possible or Impossible?" First printing Zondervan, 1973; private reprint © 1993 p.98
4. Same as reference number 2.
5. Emile Borel, "Probabilities and Life", Dover 1962, chapters 1-3.

Anonymous said...

It can get quite depressing having to refute this hoary old argument time and time again. Take two packs of cards and shuffle them, then deal them out. The probability of this particular sequence of cards occurring is 1 in 104! (! Is a mathematical operation which is shorthand for 104 X 103 X 102 X … X 2 X 1), which works out at 1 in 10^165 (The ^ is the power operator). BUT this particular sequence of cards still occurred.
Try doing the same thing with ten packs of cards - the probability of any particular sequence of cards occurring is 1 in 520!. Most calculators and computers tend to hide under the bed in terror when asked to perform this calculation (my calculator takes the easy way out and reports it as 1 in “infinity”). BUT all you need to perform this absolutely impossible miracle of probability is ten packs of cards!
This site gives a good introduction to the technical issues involved:
For a bit of light relief, try this site: