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C1-3) If a mutation does not help an organism reproduce, there will not be any pressure for that change in genetic information to promulgate.
* This is microevolution by natural selection. We see it all the time in antibiotic-resistant bacteria.
Alun wrote:C3-4) Evolution in the past can be explained as a consequence of species divergence due to reproductive pressure.
ape wrote:Your conclusions are fair and excellent!:)
Belinda wrote:Aren't some mutations linked with other,more reproduction -significant mutations? I mean, some of the traits we see in various creatures may not help the individual to live to be someone's ancestor because that trait is either redundant or is positively bad for the possible ancestor but because it is linked to and trumped by the 'good' trait, it survives.
Meleagar wrote:If we assume that a process which can acquire X amount of variation (microevolutionary variances), it does not follow that such a process can achieve any amount of variation or change, because the landscape between two variances might include obstacles that are categorically different than that which is known to be travresable by the accepted process.
I intended to refer to the overall effect of a single process of mutation--rather than a single changed gene, which seems to be how you read it.
Belinda wrote:My mistake. I note your reply to Meleagar, about this being a philosophy forum, not a science form.I will try to remember your phrase 'conceptually convincing'.
Belinda wrote:However, in our capacity as philosophers, is the motivations of the particular philosopher relevant or not?
What I am saying ...
Perhaps if you could be more specific, I could understand your criticism. Here is what I hear you saying so far: I gave examples of two species that diverged from a single species do to reproductive selective pressure. That is, evolution from point A to point B.
You're saying that when species divergence occurred from point C to D to E in the past, it is unreasonable to suppose and gather evidence which suggests it might have happened in the same manner as it has been observed between A to B. What I don't understand is what is distinct about the past scenario that makes this unreasonable.
Scott wrote:I also think the walking to the moon example is a false analogy. Walking to the moon is categorically different to walking across town in a way that walking across the country is not categorically different than walking across the town.
In contrast, developing the trait of stereoscopic vision or any one of traits that in combination enable one to fly is not categorically different than developing other traits.
I could see how it would be categorically different to suggest a mouse suddenly gave birth to a bat capable of flight or that a bird gave birth to a fish capable of breathing under water. But of course the numerous drastic differences between those species are extremely greater than the differences that would evolve in a single generation or in a single instance of speciation. But when species G evolves from F which evolved from E which evolved from D which evolved from C which evolved from B which evolved from A, the difference between A and G may be much greater than the difference between A and B or between B and C, etc. This is part of why the moon analogy fails--because the question isn't so much whether the difference between G and A is categorically different than the difference between B and A but rather the question is whether the difference between G and F is categorically different than B and A.
If walking across the country can be done by walking across town after town, then even though the difference between 1000 miles and 10 miles is great the difference between any one 10-consecutive-mile set in the 1000 miles and any other 10-consecutive-mile set is not so great; thus it is reasonable to say that both can be done by walking. The theory of evolution does not call for a leap as great as going from point A to F directly, but rather through a gradual step-by-step process, and unlike the difference between going to the moon and going across town, none of those small, gradual steps is that categorically different than the rest. For example, in reference to flying, even among the species that are currently alive right now--not counting the billions who have gone extinct--we can see a vast spectrum from those that can not fly including completely flightless birds and those that can fly best of all with many shades of grey in the middle marked by species who can glide a little to ones who fly for brief, awkward sets occasionally.
Meleagar wrote:Yes, that was my point. Until one knows they are not making a categorical mistake, then claiming that a process that can lead to one goal can accumulatively lead to the other. We don't know that the two goals are in the same category.
Meleagar wrote:Please support this assertion. You might begin by defining "traits", then showing what traits have been empirically demonstrated to be produced by natural selection, and what is involved in generating a trait like stereoscopic vision.
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