Is “Natural Selection” a Superior Explanation?

_{Barry Arrington

October 9, 2014

Intelligent Design}

Share: Facebook; Twitter; LinkedIn; Flipboard; Print; Email

As so often is the case, one of Eric Anderson’s comments got me to thinking. Here it is:

in those extremely rare cases when we know what actually caused the differential survival, we can point to the actual cause without ever invoking a label of “natural selection” to help explain the process. And in those cases in which we don’t know what actually caused the differential survival, attaching a label of “natural selection” does not help us get any closer to an explanation. Indeed, more often than not it obscures.

I decided to test this. As Michael Behe discussed extensively in The Edge of Evolution, we know what causes Plasmodium to develop antibiotic resistance. Chloroquine resistance in Plasmodium is due to a fault in a transport protein that moves the poison into the organism’s vacuole.

OK. Let’s test Eric’s assertion.

Explanation 1: When a strain of Plasmodium develops antibiotic resistance due to a fault in a transport protein that moves the poison into the organism’s vacuole, that strain has comparatively higher reproductive success than strains that have not developed such resistance.

Explanation 2: Plasmodium strains that develop antibiotic resistance due to a fault in a transport protein that moves the poison into the organism’s vacuole are more fit, and that fitness is selected for by natural selection.

How is explanation 2 superior to explanation 1? If it is not superior, why is it necessary?

Comments

phoodoo, Evolution seems to always send one down a dead end road, where the further you go, the less healthy the population. It wants to come back to what its always been. I'm not sure I understand how this applies to family Canidae. Left alone, a Racoon dog does not turn into a Fox or a Wolf (Dog). In addition, because of chromosomal differences, many fox species can not interbreed, and thus can not "revert" or collapse into single species. That would mean that Canidae is not one baramin, or three, but possibly a dozen or so.rhampton7_{October 10, 2014
October
10
Oct
10
10
2014
06:00 PM
6
06
00
PM
PDT}

Eric, My impression of what Mahuna was saying, was simply that regardless of what you want to call the process of some individuals being more fit in an environment and surviving more than others who have slightly different compositions, the end game is that all of this variations are of little value to long term change, because invariably, just like in selective breeding exercises, there are costs for each of these variations, that are less robust than the common mutt variety. Things always want to return to one standard form. A dog is a dog and a bacteria is a bacteria-no matter how we manipulate it, soon enough it wants to return to what it always has been, the uncompromised version. Evolution seems to always send one down a dead end road, where the further you go, the less healthy the population. It wants to come back to what its always been.phoodoo_{October 10, 2014
October
10
Oct
10
10
2014
07:19 AM
7
07
19
AM
PDT}

I had hoped to work this up into a full OP and have it guest hosted, but it seems appropriate to post it here given the title of the OP.
At present there is no principled way of deciding who is right about the modal status of traits like smiling. This state of affairs places evolutionary biology in a particularly unwelcome position. For no putative explanation of a given phenomenon is warranted if it cannot eliminate relevant alternative explanations in a principled fashion. So, as things stand, evolutionary biologists appear to be committed to the following inconsistent set of individually plausible propositions: 1. One of the great merits of the neo-Darwinian synthesis is its extraordinary explanatory power. Indeed this explanatory power is one of the best reasons we have for accepting this theory as a true account of the living world. 2. Explanations in evolutionary biology are couched in terms of contrastive causes and alternative effects. 3. Contrastive explanations presuppose a reliable grasp of the modal character both of the effect and the non-actualised alternatives, but 4. There is currently no consensus on how to determine the modal character of the effect and the non-actualised alternatives. When presented in this fashion the challenge facing evolutionary biology is obviouos enough. The explanatory power of evolutionary biology must be illusory if (2), (3), and (4) are true. I do not wish to abandon evolutionary biology, nor do I think this is a serious option. But I see no way of plausibly denying (2) and (3). The only way to deal with this challenge is to rectify the state of affairs described by (4). - Stephen Boulter, Contrastive Explanations in Evolutionary Biology, in Classifying Reality.
Mung_{October 9, 2014
October
10
Oct
9
09
2014
05:24 PM
5
05
24
PM
PDT}

mahuna:
I think you’re being silly here. Behe explains the biology behind how a change can occur. The fact that the change has benefits for reproduction falls under the mechanism called “natural selection”. So we can in fact demonstrate that in isolated populations over short periods of time the mechanism called natural selection can do the same thing that humans can do through the mechanism called selective breeding.
I'm not sure whom you're referring to, but your paragraph misses the key nuance. Natural selection is not a mechanism. It is not a force. It is simply a label attached to the stochastic outcome of various real, physical forces which in most cases are left largely unknown or unstated. Again, if we want to agree that we are always going to use the words "natural selection" as a shorthand way to refer to various largely unknown, unidentified, undefined biological and environmental criteria, then fine. But then let's be very clear that that is all we are doing. The logical problem comes when natural selection, as is all too often the case, is trotted out as an explanation for this or that organism's survival. This is a nuance, yes. And one that takes some thought to put our heads around. But pointing out this fact and highlighting the rhetorical games played with "natural selection" (per the excellent quote from Remine that Mung provided above), is most certainly not silly.
So what can’t be demonstrated is any natural selection string that provides a trait of such obvious and general advantage that a new species arises from the series of natural selections. Even after 150 years of Darwin’s finches.
Quite true. And this is where much of the practical debate is focused. I apologize for referring to my own comment in a prior thread, but since I've already written it, it might be best to just link. At any rate, right down the lines of your comment -- and how it relates to my nuanced criticism of natural selection -- my response to Box may be of interest in case you haven't seen it before: https://uncommondescent.com/intelligent-design/commenter-apparently-believes-that-only-part-of-darwinian-evolution-is-blindmindlessunguided-maybe-if-we-ask-nice-he-will-enlighten-us-poor-benighted-id-slobs-about-which-part/#comment-486594Eric Anderson_{October 9, 2014
October
10
Oct
9
09
2014
05:13 PM
5
05
13
PM
PDT}

Mung @6, your quoted passage is essentially saying that evolutionists are weavers of lies and deception. But we knew that.Mapou_{October 9, 2014
October
10
Oct
9
09
2014
05:02 PM
5
05
02
PM
PDT}

Thanks, Mung. A very apt description of what so often occurs in the rhetorical game.Eric Anderson_{October 9, 2014
October
10
Oct
9
09
2014
05:01 PM
5
05
01
PM
PDT}

Inventive natural selection is the distinctive evolutonary mechanism - essential to Darwinian theory. Evolutionists presume it creates new adaptations by somehow traversing the hills and valleys of the fitness terrain. But they do not attempt to defend it as testable science. Rather, for the defense they shift back to the naive version - survival of the fittest. Then they might offer some tautology to help expunge all doubt. When challenged, they shift between various formulations. They use naive natural selection to convince the public that evolution is simple, testable, and virtually inevitable. When opponents point out that such continually uphill evolution is refuted by the data, evolutionists effortlessly shift away from naive natural selection. Then they charge that the opponent has a poor understanding of evolutionary theory. In short, evolutionists merely shifted away from criticism, then focused their arguments (and your attention) in a direction that seemed to overcome the criticism. This phenomenon occurs at several levels. Biological adaptation by natural selection is not inevitable, nor is the theory scientific. It had merely lent support to the philosophy of naturalism. - Walter James ReMine. The Biotic Message
Chapter 4 of this book is a must read. Heck, the entire book is a must read!Mung_{October 9, 2014
October
10
Oct
9
09
2014
04:14 PM
4
04
14
PM
PDT}

Plasmodium did not evolve "antibiotic resistance". The defect was already there. This is a case of survival of the defective. "Oh, but defective means fittest in this case". Whatever. Literally, whatever.ppolish_{October 9, 2014
October
10
Oct
9
09
2014
02:06 PM
2
02
06
PM
PDT}

I think you're being silly here. Behe explains the biology behind how a change can occur. The fact that the change has benefits for reproduction falls under the mechanism called "natural selection". So we can in fact demonstrate that in isolated populations over short periods of time the mechanism called natural selection can do the same thing that humans can do through the mechanism called selective breeding. The problem comes from the fact that even selective breeding suffers from the natural tendency to "revert to type". That is, if you allow show horses to mate randomly with wild horses, most of the carefully developed specialization will disappear. This is easier to show with feral dogs: overly large and overly small domestic dog breeds disappear. So what can't be demonstrated is any natural selection string that provides a trait of such obvious and general advantage that a new species arises from the series of natural selections. Even after 150 years of Darwin's finches.mahuna_{October 9, 2014
October
10
Oct
9
09
2014
01:25 PM
1
01
25
PM
PDT}

Thanks, Barry. I appreciate the kind words and the specific example to help make the point. I would just add that even Explanation 1 is in need of additional details: "Explanation 1: When a strain of Plasmodium develops antibiotic resistance due to a fault in a transport protein that moves the poison into the organism’s vacuole, that strain has ~~comparatively higher reproductive success than~~ __ % less likelihood of contracting the poison (based on observations), which coupled with the particular environmental factors a, b and c, result in an overall greater likelihood of survival in the particular environment of __ %, compared to strains that have not developed such resistance." The point is that when we really know what is going on -- what is really occurring at the molecular level, with the molecular machines, as integrated into the overall organism, within the particular environment -- at that point we can now (and not before) point to an actual cause of organism X's comparative survival over organism Y. Again, we could use the two words "natural selection" to describe that process in a shorthand way. The problem that comes up so often with natural selection is a combination of the facts that: (i) the underlying detail is almost always missing or poorly understood, (ii) natural selection has historically been personified as some kind of actual force in nature when it is not, and (iii) the speaker generally is lulled into thinking that by invoking "natural selection" they have somehow explained the phenomenon in question, when all they have done is gloss over our lack of understanding of what really happened. Anyway, somewhat esoteric, but I think these are important nuances for us to keep in mind.Eric Anderson_{October 9, 2014
October
10
Oct
9
09
2014
12:10 PM
12
12
10
PM
PDT}

I have one also... 1) parasitic fly feed on chirping crickets. Noisy ones get eaten, quiet ones don't. Quiet ones become plentiful. 2) crickets evolve quietness through Natural Selection,ppolish_{October 9, 2014
October
10
Oct
9
09
2014
11:55 AM
11
11
55
AM
PDT}

Natural Selection = death ...speaking of death - Staying Ebola Free – Helpful Tips on Avoiding Ebola Heartlander_{October 9, 2014
October
10
Oct
9
09
2014
09:26 AM
9
09
26
AM
PDT}

You must be logged in to post a comment.

Leave a Reply