Randomness

[PhDP]

Here's an interesting article about the biais of biology students against randomness (something we see here very often, thank you very much Dawkins);

 

http://biology.plosjournals.org/archive/1545-7885/6/1/pdf/10.1371_journal.pbio.0060003-S.pdf

 

Both Lander and Lynch suggest that many professional biologists have problems appreciating the power of random processes. Given that much of evolutionary change is ultimately driven by, or is the result of, random processes rather than selection acting alone, and given the apparent tendency of students to reject or overlook random events as the cause

of emergent behaviors, what emerges is “neo-vitalist” mindset that presumes

the presence of directed processes and imposes a level of meaning on the

system (and its components) that may well not be present. Not all genetic changes have an immediate adaptive significance, and not all molecular

processes are actively directed. Does this view interfere with understanding?

The answer must be yes—since it leads one to assign purpose to a process (be it evolution or osmosis), and ignores what can be achieved at the underlying molecular level. From an evolutionary perspective, it leads to “just-so” stories that project meaning onto every variation, whether meaningful or not, and obscures the basic mechanisms that make evolutionary theory so valuable.

 

And the surprising part;

 

Lecoutre et al. describe an enlightening study of concepts of randomness and probability among French middle school students, psychology graduate students, and mathematicians, concluding that there exists a significant level of confusion in all groups.

[lucaspa]

First, "randomness" is used specifically in evolution. Lots of people misuse the word, and that is where a lot of the confusion lies. For instance, the phrase "Given that much of evolutionary change is ultimately driven by, or is the result of, random processes rather than selection acting alone" misportrays the role "random" plays in natural selection.

 

Natural selection is a two step process:

1. Variation

2. Selection.

 

The variation is "random". That is, individuals in the population vary randomly with respect to the needs of the individual or the population. Selection is totally non-random. Selection never acts "alone"; it must always be coupled with variation. No variation, no selection (among variants).

 

Second, natural selection does indeed have a "purpose", a short-term purpose. And that purpose is to design the population to cope with the present environment. What is overlooked is that natural selection is an algorithm (unintelligent process) that gives design. Once that is understood, everything else becomes clear. The environment presents design problems to the population. Natural selection solves those design problems, allowing the population to survive and prosper.

 

When people say natural selection has no "purpose", they mean no long-term purpose. Natural selection cannot "see" ahead to future environments. So it cannot "plan" for them and get the population ready for those future environments.

 

Dawkins made the use of the word "random" in evolution very clear:

 

"Darwinism is widely misunderstood as a theory of pure chance. Mustn't it have done something to provoke this canard? Well, yes, there is something behind the misunderstood rumour, a feeble basis to the distortion. One stage in the Darwinian process is indeed a chance process -- mutation. Mutation is the process by which fresh genetic variation is offered up for selection and it usually described as random. But Darwinians make the fuss that they do about the "randomness" of mutation only in order to contrast it to the non-randomness of selection, the other side of the process. It is not necessary that mutation should be random in order for natural selection to work. Selection can still do its work whether mutation is directed or not. Emphasizing that mutation can be random is our way of calling attention to the crucial fact that, by contrast, selection is sublimely and quintessentially non-random. It is ironic that this emphasis on the contrast between mutation and the non-randomness of selection has led people to think that the whole theory is a theory of chance." R Dawkins, Climbing Mt. Improbable, pp 80- 82.