Types of mutations in coevolution
There are the following basic types of mutations in coevolution:
(1) A mutation in just one species produces a benefit for that species and maybe also for other species -- there is no need for a corresponding mutation in another species (and in parasitism and predation a corresponding mutation in other species might actually counteract the first mutation's benefit). This type of mutation is common in parasite/host and predator/prey relationships. Because a benefit is produced, such a mutation is likely to spread rapidly, and such a rapid spread will increase the chances that this mutation will meet a corresponding mutation in another kind of organism. Sometimes this single mutation may never meet a corresponding mutation in another kind of organism -- that situation is sometimes not considered to be coevolution because the prefix "co" means "mutual," "together," or "reciprocal," implying that there are corresponding adaptations in other kinds of organisms. However, if the prefix "co" is interpreted as meaning "together" with other living things, then even a one-sided adaptation to other living things can be considered to be coevolution. Whether or not a mutation is coevolutionary should not depend on whether or not there is ever a corresponding mutation in another type of organism, hence IMO all mutations that are adaptations to other organisms should be considered to be coevolutionary. A one-sided adaptation could be difficult if the adaptation is very specific and complex, e.g., some kinds of parasitisms and orchids' mimicry of female wasps' sex pheromones. I propose calling these one-sided adaptations "unilateral" coevolutionary adaptations or mutations.
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(2) Corresponding mutations are required in both kinds of organisms to produce a benefit. Isolated mutations of this type (i.e., mutations not accompanied by the corresponding mutation in the other organism at the same time and place) will not tend to spread rapidly because there is no benefit and hence will have a low tendency to meet a needed corresponding mutation, and this is obviously a big problem for coevolution. This type of mutation can be further subdivided into mutations that are neutral when isolated and mutations that are fatal or harmful when isolated -- the latter type of mutation is obviously even less likely to survive and spread. This need for corresponding mutations can exist even where coevolution can be gradual. An additional problem with this kind of mutation is that the two kinds of organisms might only be able to interact in large numbers, requiring large numbers of both kinds of organisms to suddenly appear at the same time and place. I propose calling these two-sided adaptations "bilateral" coevolutionary adaptations or mutations.
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(1) A mutation in just one species produces a benefit for that species and maybe also for other species -- there is no need for a corresponding mutation in another species (and in parasitism and predation a corresponding mutation in other species might actually counteract the first mutation's benefit). This type of mutation is common in parasite/host and predator/prey relationships. Because a benefit is produced, such a mutation is likely to spread rapidly, and such a rapid spread will increase the chances that this mutation will meet a corresponding mutation in another kind of organism. Sometimes this single mutation may never meet a corresponding mutation in another kind of organism -- that situation is sometimes not considered to be coevolution because the prefix "co" means "mutual," "together," or "reciprocal," implying that there are corresponding adaptations in other kinds of organisms. However, if the prefix "co" is interpreted as meaning "together" with other living things, then even a one-sided adaptation to other living things can be considered to be coevolution. Whether or not a mutation is coevolutionary should not depend on whether or not there is ever a corresponding mutation in another type of organism, hence IMO all mutations that are adaptations to other organisms should be considered to be coevolutionary. A one-sided adaptation could be difficult if the adaptation is very specific and complex, e.g., some kinds of parasitisms and orchids' mimicry of female wasps' sex pheromones. I propose calling these one-sided adaptations "unilateral" coevolutionary adaptations or mutations.
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(2) Corresponding mutations are required in both kinds of organisms to produce a benefit. Isolated mutations of this type (i.e., mutations not accompanied by the corresponding mutation in the other organism at the same time and place) will not tend to spread rapidly because there is no benefit and hence will have a low tendency to meet a needed corresponding mutation, and this is obviously a big problem for coevolution. This type of mutation can be further subdivided into mutations that are neutral when isolated and mutations that are fatal or harmful when isolated -- the latter type of mutation is obviously even less likely to survive and spread. This need for corresponding mutations can exist even where coevolution can be gradual. An additional problem with this kind of mutation is that the two kinds of organisms might only be able to interact in large numbers, requiring large numbers of both kinds of organisms to suddenly appear at the same time and place. I propose calling these two-sided adaptations "bilateral" coevolutionary adaptations or mutations.
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posted by Larry Fafarman | 7/06/2009 10:03:00 PM
10 Comments:
I was starting to think you weren't serious about writing this paper. This is a good start - you need to get your ideas down on paper. Since this paper is intended for an academic journal, you'll have to work it up to academic standards, including backing up your thoughts with references, but for now you can just concentrate on getting your thoughts down on "paper" as it were.
That said, I'd like to offer two observations.
First, although it is implied, I think you really need to state something explicitly. What you call a unilateral mutation can be benificial on its own and mutually reinforcing in the presence of a corresponding mutation.
Second, a mutation is not the same thing as a trait. A mutation is a change in a trait, delta-trait if you will. As a consequence, it is entirely possible for a mutation in an obligate mutualism to be a unilateral mutation, even though the traits themselves are, to use your term, bilateral.
>>>>>> I was starting to think you weren't serious about writing this paper. This is a good start <<<<<<<
Actually, this post was not intended to be the start of a paper, though it could be incorporated into a paper. And the ideas expressed here are mostly a rehash of ideas that I have already posted on this blog.
It is hard to find the time to write a paper -- there are so many distractions.
>>>>>> First, although it is implied, I think you really need to state something explicitly. What you call a unilateral mutation can be benificial on its own and mutually reinforcing in the presence of a corresponding mutation. <<<<<<
That's true -- but if it is beneficial on its own, at least it will have a tendency to spread rapidly without a mutually reinforcing mutation in another organism -- and sometimes the mutation in the other organism can be opposing, as in the "arms races" of parasitism and predation.
>>>>>> Second, a mutation is not the same thing as a trait. A mutation is a change in a trait, delta-trait if you will. <<<<<<<
A mutation is not necessarily a change in a trait -- a mutation can be something completely new, with no precursor.
>>>>> it is entirely possible for a mutation in an obligate mutualism to be a unilateral mutation <<<<<<
Yes, in describing the two types of mutations, I did not restrict them as to the type of relationship, e.g., obligate mutualism, parasitism, and commensalism.
This is an improvement over your usual braying.
What? Does that mean that you agree that coevolution is a weakness of evolution theory?
> What? Does that mean that you agree that coevolution is a weakness of evolution theory? <
Of course not. It looked like you were finally accepting that it was not a weakness.
> I said, "this is obviously a big problem for coevolution." >
You neglected to put that in this post.
>>>>>> You neglected to put that in this post. <<<<<<<
I might have -- I sometimes make small, trivial additions or changes after I publish a post. However, it should have been obvious from the rest of my post -- as well as from my other posts on this blog -- that I was describing what I believe to be a weakness of evolution theory.
>>>>>> After which you admit you didn't say it. This makes you look like a stupid fathead. <<<<<<<
No, I did not admit that I didn't say it. I said that it might not have been in the original post. However, I checked the post's final draft and the statement "this is obviously a problem for coevolution" was there, so it probably was in the original post. Anyway, I said that I otherwise made it clear that I consider coevolution to be a weakness of evolution theory.
Observation: Unilateral mutations are not a problem for evolution
Fact: Neutral mutations greatly outnumber benficial mutations
Observation: Due to their large numbers, neutral bilateral mutations are not a problem for evolution
Observation: Harmful bilateral mutations are a problem for evolution
Fact: Almost all obligate mutualisms can be traced to unilateral or neutral bilateral mutations
Conclusion: Coevolution is not a problem for evolution
What a dumb comment.
>>>>>> Fact: Neutral mutations greatly outnumber benficial mutations <<<<<<
So what?
>>>>> Due to their large numbers, neutral bilateral mutations are not a problem for evolution <<<<<<<
I never said they were a problem. And why do you say that there are large numbers of them? Bilateral mutations are beneficial when in combination with a corresponding mutation in another kind of organism, and beneficial mutations of any kind are rare.
>>>>> Observation: Harmful bilateral mutations are a problem for evolution
Fact: Almost all obligate mutualisms can be traced to unilateral or neutral bilateral mutations <<<<<<
What support do you have for that "fact"?
>>>>>> Conclusion: Coevolution is not a problem for evolution <<<<<<<
What about the obligate mutualisms that cannot "be traced to unilateral or neutral bilateral mutations"?
Also, I never said that my post here discussed all the problems of coevolution -- for example, there is the problem of extremely specific and complex adaptations in parasitism.
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