By Daniel Miessler on October 24th, 2005: Tagged as Science
Since every improvement in one species will lead to a selective advantage for that species, variation will normally continuously lead to increases in fitness in one species or another. However, since in general different species are coevolving, improvement in one species implies that it will get a competitive advantage on the other species, and thus be able to capture a larger share of the resources available to all. This means that fitness increase in one evolutionary system will tend to lead to fitness decrease in another system. The only way that a species involved in a competition can maintain its fitness relative to the others is by in turn improving its design.
The Red Queen Principle
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There are some logical flaws in that principle (or at least in that statement of it). “Improvement” in a species does not LEAD to selective advantage … it is DEFINED as selective advantage … or rather is defined as improving the ability to reproduce successfully. In this way, the “improvements” are “selected” for. It certainly does not follow that “variation” normally continuously leads to increases in fitness. Variation by random mutation is random. Sometimes it leads to increases in fitness, sometimes not (probably USUALLY not). It is true that species have evolved simultaneously (in a geologic sort of time frame), but it does not follow that improvement in one species necessarily implies a disadvantage in others. Life in Earth’s biosphere is NOT a zero-sum game. The fact that one species gains does NOT mean that another species must lose. Interactions among species do not really boil down to the simplistic notion of two species competing for the same resources. It is more complicated than that. Even in cases of preditor-prey relationships between species where one might expect the prey species to benefit from the destruction of the preditor species, things can get complicated. In some cases, destruction of the preditor species would cause the prey species to temporarily flourish (in a population explosion) … only to find that they have exhausted their own food resources. This can have devastating results on the prey species (including potentially leading to their extinction).
Comment by Carl M — 10/24/2005 @ 8:58 pm
While each individual mutation is random, and doesn’t necessarily lead to anything that improves a given species, on a large scale, over time, mutation does (indirectly) tend to improve species.
The reason for this is that changes take place and nature selects those that are succssful. The mutation itself didn’t know this was going to happen; it just happened. And depending on environment, the current competitors, and a whole myriad of other factors, the changes either help the species or hurt it. Well, if they hurt it, then those with that set of traits gets phased out due to competition. If it helps, they become one of the new standards.
I think that’s all that’s being said here — not something else along the lines of intelligent design.
Comment by Daniel — 10/25/2005 @ 10:52 pm
I didn’t see it as being along the lines of intelligent design. Perhaps my complaint there was more with the word “continuously.” In fact, improvements (when they occur) are by their very nature discrete (as opposed to continuous).
But my bigger issue is with the “success here” means “failure there” viewpoint. In addition to the preditor-prey example I gave, let me give an example that brings to light the implied assumption that the “resources available to all” is some FIXED amount of resources. That’s simply not true. If a plant evolves a more efficient method of extracting energy from sunlight and uses it to store extra energy reserves for an uncertain future, that could GREATLY benefit those who feed on the plant. And, it may or may not cause harm to other species. One could certainly envision a situation in which no harm came to other species.
The assumption that every competitive situation is a zero-sum game is a common one. However, it is a false one.
Comment by Carl M — 10/26/2005 @ 11:36 am