Random chance

From RationalWiki
Jump to: navigation, search
A gradually improving article series on

Evolution

Icon evolution.svg
People
Science
Pseudoscience

A common claim by creationists is that evolution is nothing but random chance which they then follow by claiming that there is no way random chance could produce a particular adaptation or animal. This is most commonly used in association with an argument from design.

The "random chance" criticism is actually a straw man, since evolution does not rely only on random chance. While some elements of evolution are random, most notably mutation, the cornerstone of Charles Darwin's theory is natural selection, which is the opposite of chance. Natural selection is non-random and is one of the primary shaping forces for adaptation in nature. By ignoring natural selection in evolution, creationists are better able to argue that a god must have intervened, which is completely fallacious.

It is also interesting that because creationism makes no attempt (for it would represent a merely human limitation on divine power) to describe any regularities about the world, or to discriminate between what might happen and what might not happen as a consequence of creation (or intelligent design), there is no difference between the results of divine creation and random chance. While evolutionary biology rules out certain things - it is extremely unlikely that there would be a rabbit with ceramic armor or a supersonic hawk (unless a mad scientist decided to design one) - there is nothing that is less plausible than anything else in a creationist's world.

If we can say that "random chance" operates in evolution, we can say that it operates elsewhere in the world of life. One striking example is in the action of the adaptive immune system in jawed vertebrates. We jawed vertebrates are protected against diseases caused by certain viruses, fungi, bacteria, and parasites by changing our immune system to meet novel assaults. The adaptive immune system is the reason why vaccination works, and why we get certain diseases only once. The adaptive immune system generates great numbers of cells to detect alien biological molecules, and by "random chance" eventually one of these cells makes a match. This then allows our immune system to destroy the source of this novel alien molecule. As it turns out, relying on this "random chance" provides better protection against certain diseases than anything that we humans can "intelligently design".

"Random chance" is not incompatible with "intelligent design", or the achievement of goals. Creative artists often avail themselves of chance effects. There is the crackle glaze in pottery, which deliberately achieves artistic effects by encouraging the random patterns in the cooling of the pottery when it is removed from the kiln. Bronze outdoor sculptures are designed to acquire a patina. Performers respond to the unpredictability of the audience. Composers and playwrights release control over their works to the interpretation of the performers. Photographers and other visual artists respond to what is presented to them, for example the appearance of the model.

Contents

[edit] Malaria: A case study

The efficacy of evolution vs. design can be studied with respect to the malaria parasite and the ways of combatting it.[1] The standard evolutionary explanation for the development of sickle-cell anemia in humans is that it provides protection against the malaria parasite. Sickle-cell anemia is generally recognized as a result of a random mutation. It can cause a debilitating disease in humans, yet it also, more often, provides a defense against malaria. There are also several other random mutations in humans which can both cause diseases and defend against malaria. In the hemoglobin alpha chain, there are point mutations HbS, HbC, HbE; in the hemoglobin gamma chain, there is HPHF; in various parts of hemoglobin, there is thalassemia; and others.(page 39)[1] These various random mutations have provided defenses against malaria which have been working for a long time. We may characterize the competition between the random human evolution and the random malaria evolution as a stand-off. In contrast, there are the human-designed defenses against malaria. It is famous how malaria has evolved resistance to just about everything that we can design to go against it. Despite our best designs, not limited to drugs, the deaths from malaria continue in great numbers. (page 17)[1] "Resistance to one recent drug, atovaquone, arose in the lab scant weeks after a small culture of malaria was exposed to it. Almost a hundred thousand times as many clicks of the clock have passed since [the first appearance of sickle-cell]. About that much time since [HbC] ... and since thalassemia first appeared. Yet they are all still effective against malaria."(page 52)[1] On the other hand, the drug which was not designed seems to be somewhat intermediate: "Quinine, the natural drug that first turned the tide of battle toward humanity's side, is still pretty effective against [the malaria parasite]. But the bug is slowly gaining ground ... ."(page 260)[1]

In summary, in a contest between "random evolution" and "design", random is not just effective, but more effective; the closest contest is between the "random evolution" and the "chance discovery" of quinine.

[edit] So what does the Bible say about random chance?

Are the two elements needed for natural selection -- time and chance -- heretical or biblical? Bible thumpers should check out Ecclesiastes 9:11.

I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all.[2]

Whereas this verse is agreeable when read on its own, it's got problems when read in context. If one were to read the next verse, we would see:

For man also does not know his time: Like fish taken in a cruel net, Like birds caught in a snare, So the sons of men [are] snared in an evil time, When it falls suddenly upon them

The point of the verse and all of Ecclesiastes (if one was to actually read it) would be that man is nothing but random chance without God, that there is no value in a life without God. That is exactly the point of creationists. If this is taken in context with the rest of the bible we know that God is all knowing, so things to man may seem random, but they aren't to God. God creating the world with purpose would mean there would be no random chance, or selection.

[edit] See also

[edit] External links

[edit] Footnotes

  1. 1.0 1.1 1.2 1.3 1.4 The information presented here is taken from: Michael J. Behe, The Edge of Evolution: The Search for the Limits of Darwinism, New York: Free Press, 2007, ISBN 978-0-7432-9620-5, chapters 2 and 3 and appendix B. Behe is not responsible for this use of the data. He was making a quite different point: indeed, he claims that this shows a very narrow limit to the range of possibilities open to evolutionary development. Whether his point was made is irrelevant to the topic of this article.
  2. Emphasis added.
Personal tools
Namespaces

Variants
Actions
Navigation
Community
Tools
support