It’s always awesome to see Richard Dawkins in action, but where’s the substance? So rhino horn count might or might not be adaptive. Blood groups might or might not be adaptive. The ‘tongue-rolling’ gene might or might not have adaptive pleiotropic effects. These questions aren’t ‘boring’ exactly but they’re minutiae.
Reading Darwin’s Dangerous Idea gave me the impression that the fundamental divide between the “adaptationists” and their opponents is whether all non-trivial instances of “design” in nature are the result of natural selection (including sexual selection) for something (which may or may not be the same thing that the design is currently used for) or whether somehow ‘constraints’ and genetic drift can funnel the progress of evolution towards complex (“designed-looking”) characteristics that confer no adaptive advantage.
(To me, the latter still seems weird and unmotivated, though I’m not ideologically wedded to it being wrong.)
… whether somehow ‘constraints’ and genetic drift can funnel the progress of evolution towards complex (“designed-looking”) characteristics that confer no adaptive advantage.
(To me, [that] still seems weird and unmotivated, though I’m not ideologically wedded to it being wrong.)
I suppose the epistemological point that Lewontin would harp on here is that if you go in expecting Nature to only do things that seem well-motivated and ‘natural’, then you are going to produce ideologically biased science.
But as to whether evolution can produce complex ‘designed-looking’ characteristics that are not positively adaptive, give a look to this single-topic blog by Arlin Stoltzfus and this paper discussing an idea known as Constructive Neutral Evolution (pdf).
The last features a pretty bizarre definition of “neutral”:
In this broader sense, “neutral” changes would include not only random fixations and genetic hitchhiking (fixation of an allele tightly linked to a selected allele), but also pleiotropic effects of selective allele fixations.
It’s always awesome to see Richard Dawkins in action, but where’s the substance? So rhino horn count might or might not be adaptive. Blood groups might or might not be adaptive. The ‘tongue-rolling’ gene might or might not have adaptive pleiotropic effects. These questions aren’t ‘boring’ exactly but they’re minutiae.
Reading Darwin’s Dangerous Idea gave me the impression that the fundamental divide between the “adaptationists” and their opponents is whether all non-trivial instances of “design” in nature are the result of natural selection (including sexual selection) for something (which may or may not be the same thing that the design is currently used for) or whether somehow ‘constraints’ and genetic drift can funnel the progress of evolution towards complex (“designed-looking”) characteristics that confer no adaptive advantage.
(To me, the latter still seems weird and unmotivated, though I’m not ideologically wedded to it being wrong.)
I suppose the epistemological point that Lewontin would harp on here is that if you go in expecting Nature to only do things that seem well-motivated and ‘natural’, then you are going to produce ideologically biased science.
But as to whether evolution can produce complex ‘designed-looking’ characteristics that are not positively adaptive, give a look to this single-topic blog by Arlin Stoltzfus and this paper discussing an idea known as Constructive Neutral Evolution (pdf).
The last features a pretty bizarre definition of “neutral”: