Whoa! Whoa! dhw take notice!!! (The limitations of science)

by dhw, Tuesday, April 22, 2014, 14:11 (3869 days ago) @ xeno6696

MATT: Whoa! Whoa! Hold on just a minute here! My definition of Natural Selection was this: "Natural selection is a function that takes two inputs, a group of genetically compatible organisms, as well as changes in environment, and its output is changes in frequencies of certain alleles within that group of organisms, where the alleles can be traced back to the changes in environment."-I'm sorry I didn't recognize this as a definition, but as your previous post continued, I thought I was getting a clearer idea of what you were trying to say, and pointed out that my only disagreement was with your use of "NS", which I would have replaced with "evolution". I have a similar objection to this definition. (I appreciate your honesty in admitting that you sometimes conflate the two terms.) It seems to me that you are trying to incorporate all the phases of evolution into a computer programme called NS (function, input, output etc.?). Your definition does not even indirectly involve selection or the outcome of selection, which I would have thought was essential ... a dead organism will also undergo changes! ... and also it suggests that NS is responsible for the changes (see below), whereas it selects existing changes which are beneficial. I do wish you would say why you object to the conventional definitions. Here's another nice, simple one: "the process by which only plants and animals that are naturally suitable for life in their environment will continue to live and breed, while all others will die out." (Longman Dic. of Contemporary English)
 
Let me skip now to your summary: "If we agree that natural selection is a process, and we can agree that it requires both existing organisms and environmental changes, and that its output are sub-populations with traits that didn't exist prior, then we are in complete agreement."-I agree and I don't agree (and I much prefer the word "process"), because you have phrased it in such a way that it is highly ambiguous, as is made clear by your last paragraph:
 
MATT: Natural selection is just a mechanism proposed to explain evolutionary change. The mechanism requires organisms and environmental events, and by repeated application of the mechanism, you'll have your explanation for evolution.-Firstly, I don't like the word "mechanism", which I think would be far more applicable to whatever physical "machinery" exists within the organism that enables it to adapt (and innovate). That's why I prefer "process", which you have also accepted. Secondly, NS does not "explain" evolutionary change, it only explains why some organisms survive and others don't. That is the "selection". And this is where the ambiguity of your earlier summary comes into play. Of course NS requires existing organisms and environmental changes, because it can only come into operation when these exist. But what it requires does not tell us what it is or does. And if by "output" you mean what is left for us to see, then yes, the output is new traits. But if you mean the new traits are the PRODUCT of NS, then no, they are the product of the evolutionary process in which environmental change triggers organic change, whereas NS decides which of the changes will survive. NS does not produce anything, and Nature cannot select organisms or changes in organisms until they exist. NS preserves what is useful. Again, let me ask you why you object to this description of the evolutionary process.